Electronic system, method for transmitting temperature information, and associated computer program

Abstract

An electronic system comprises a measuring device (2) and an electronic control unit (10) that are connected by way of a communication interface (6). The measuring device (2) comprises: - an acquisition module (20) configured to produce a matrix of temperature values on the basis of measurements carried out by a thermal sensor; and - a processing module (22) configured to determine, for each of a plurality of predefined zones of the matrix, temperature information obtained taking into account all temperature values located in the predefined zone in question. The measuring device (2) is configured to transmit the temperature information to the electronic control unit (10) via the communication interface (6). An associated method and computer program are also proposed.

Description

[0001] Description

[0002] Title of the invention: Electronic system, method for transmitting temperature information and associated computer program. Technical field of the invention

[0003] The present invention relates to the technical field of temperature measurement.

[0004] It relates in particular to an electronic system, a method for transmitting temperature information and an associated computer program.

[0005] State of the art

[0006] It is known to use a matrix thermal sensor (e.g., embedded in a thermal camera) to determine temperature information relating to a part of the environment facing that matrix thermal sensor.

[0007] Such solutions are notably used in motor vehicle interiors to obtain temperature information (e.g. average temperature, minimum temperature and / or maximum temperature) relating to a part of the environment such as a part of the body (hand or face) of an occupant of the interior.

[0008] The temperature values ​​produced by the matrix thermal sensor can be used by an electronic control unit to control the vehicle's heating and / or air conditioning system. However, this requires a connection with sufficient data transfer capacity between the thermal sensor and the electronic control unit to transmit all the temperature values ​​produced by the matrix thermal sensor.

[0009] Presentation of the invention

[0010] In this context, the present invention proposes an electronic system comprising a measuring device and an electronic control unit connected by means of a communication interface, in which the measuring device comprises:

[0011] - an acquisition module configured to produce a matrix of temperature values ​​based on measurements taken by a thermal sensor; and

[0012] - a processing module configured to determine, for each of a plurality of predefined zones of the matrix, a temperature information obtained by taking into account all the temperature values ​​located in the predefined zone concerned,

[0013] and in which the measuring device is configured to transmit temperature information to the electronic control unit via the communication interface.

[0014] The plan is to determine within the measuring device temperature information relating to predefined zones, which avoids having to transmit all the temperature values ​​of the measuring device to the electronic control unit.

[0015] The pre-processing carried out within the measuring device thus makes it possible to lighten the processing carried out by the electronic control unit and to reduce the required throughput on the communication interface.

[0016] The electronic control unit is configured, for example, to send instructions to a heating, ventilation, or air conditioning unit.

[0017] The number of elements (i.e., temperature values) in the matrix can be greater than 500 (and even greater than 900 in the example described below).

[0018] The measuring device is configured, for example, to transmit, for each acquisition of a matrix of temperature values, a number of temperature information less than 50 (for example, between 20 and 50).

[0019] The communication interface may, for example, have a data rate lower than 20 kbit / s. In practice, the communication interface may be a local interconnected network. Furthermore, the processing module may be configured to identify a set of temperature values ​​from the matrix and / or to determine at least one temperature reading based on the temperature values ​​of the identified set.

[0020] The processing module is then configured, for example, to identify said set of values ​​by identifying contiguous temperature values ​​in the matrix, within a predefined range of values ​​and whose number is between a first threshold and a second threshold.

[0021] The temperature information transmitted may include, for example, at least an average of the temperature values ​​located in one of the said predefined zones and / or at least a maximum value among (all) the temperature values ​​located in one of the said predefined zones and / or at least a minimum value among (all) the temperature values ​​located in one of the said predefined zones.

[0022] The invention also proposes a method for transmitting temperature information, comprising the following steps:

[0023] - production, by a measuring device, of a matrix of temperature values ​​based on measurements made by a thermal sensor;

[0024] - determination, by the measuring device and for each of a plurality of predefined zones of the matrix, of a temperature information obtained by taking into account all the temperature values ​​located in the predefined zone concerned;

[0025] - transmission of temperature information to an electronic control unit via a communication interface linking the measuring device and the electronic control unit.

[0026] The optional features presented above in terms of electronic system can also be applied to this process.

[0027] The invention finally proposes a computer program comprising instructions executable by a processor and designed to implement a process such as proposed above when these instructions are executed by the processor.

[0028] Of course, the different features, variants and embodiments of the invention can be combined with each other in various ways as long as they are not incompatible or mutually exclusive.

[0029] Detailed description of the invention

[0030] Furthermore, various other features of the invention become apparent from the attached description made with reference to the drawings which illustrate non-limiting embodiments of the invention and where:

[0031] [Fig. 1] schematically represents a system in which the invention can be implemented;

[0032] [Fig. 2] represents part of the system in Figure 1;

[0033] [Fig. 3] represents an example of a thermal image corresponding to a matrix of temperature values ​​as used in the invention; and [Fig. 4] is a flowchart showing the main steps of an example of a process according to the invention.

[0034] Figure 1 schematically represents a heating and air conditioning system of a vehicle (here a motor vehicle) in which the invention can be implemented.

[0035] The system in Figure 1 includes an electronic measuring device 2, which acts as a thermal detector and is located in a vehicle compartment 4. The system in Figure 1 also includes an electronic control unit 10, a ventilation unit 12, a heating unit 14, and an air conditioning unit 16.

[0036] The electronic control unit 10 controls the operation of the heating and air conditioning system and sends instructions to the ventilation unit 12 and / or the heating unit 14 and / or the air conditioning unit 16.

[0037] As shown in Figure 2, the measuring device 2 comprises an acquisition module 20, a processing module 22 and a communication unit 24.

[0038] The measuring device 2 (specifically its communication unit 24) and the electronic control unit 10 are connected via a communication interface 6.

[0039] This communication interface 6 is, for example, a local interconnected network (or LIN for "Local Interconnect Network"). In this context (or with other low-bandwidth networks), communication interface 6 may have a bandwidth of less than 20 kbit / s.

[0040] Alternatively, communication interface 6 could be an automotive communication bus, for example a CAN type bus (for "Controller Area Network").

[0041] In the example described here, the acquisition module 20 is a thermal camera equipped with a matrix thermal sensor and configured to produce a matrix of temperature values ​​based on measurements taken by this matrix thermal sensor within the environment where this matrix thermal sensor is located, here the passenger compartment 4 of the vehicle.

[0042] The elements of the aforementioned matrix are thus the temperature values ​​measured by the thermal sensor in a set of spatial directions relative to the thermal sensor. The temperature values ​​therefore indicate the respective temperatures of different regions located in the environment (here, the vehicle's interior) in different spatial directions relative to the thermal sensor.

[0043] In practice, the matrix includes, for example, a number of columns between 16 and 64 and / or a number of rows between 16 and 64. The matrix can thus include a number of elements (or pixels), that is to say a number of temperature values, greater than 256, and, in some cases, greater than 500.

[0044] For example, here we use a Heimann HTPA32x32d thermal camera, with a resolution of 32 elements x 32 elements (i.e., a number of elements greater than 900) and covering a total angular field of view of 120° x 120° so as to cover the entire passenger compartment.

[0045] Such a thermal camera practically provides a stream of matrices (for example, at a frequency between 1 Hz and 10 Hz). However, we will focus in the following on the processing of a single matrix (at a given acquisition time), as this processing can be reproduced for each matrix in the stream.

[0046] The processing module 22 is here a processor (for example a microcontroller) which receives the matrix of temperature values ​​produced by the acquisition module 20 and processes these temperature values ​​(as explained below) in order to obtain information relating to a part of the environment

[0047] It is noted that the example described here, where the acquisition module 20 and the processing module 22 physically correspond respectively to a thermal camera and a processor, represents only one possible implementation of the invention.

[0048] Alternatively, we could consider, for example, that the acquisition module 20 is implemented by the cooperation of a thermal sensor making measurements in the environment and a processor processing these measurements (due to the execution of first instructions) in order to produce the matrix of temperature values, while the processing module 22 could then be implemented either by this same processor (executing second instructions distinct from the first instructions) or by another processor.

[0049] In the case where the same processor is used to implement the acquisition module 20 and the processing module 22, a computer program (grouping the first and second instructions mentioned above) can thus include instructions executable by this processor and designed to implement a process including steps such as steps E2 to E12 described below with reference to Figure 4 when these instructions are executed by this processor.

[0050] As explained below, the processing module 22 produces, based on the temperature values ​​of the matrix, temperature information relating each to a predefined area of ​​the matrix and, optionally, temperature information relating each to an evolving set of temperature values, identified (in real time) by the processing module 22.

[0051] The processing module 22 stores (for example, in non-volatile, possibly rewritable memory) initial data defining a plurality of predefined areas within the temperature value matrix. At least some of these predefined areas may be rectangular (the use of non-rectangular areas is also possible). One of the predefined areas may, for example, cover the entire temperature value matrix.

[0052] Several methods are possible for defining each predefined area using the initial data. For example, when the predefined area is rectangular, the initial data could include the coordinates (row and column in the matrix) of the upper-left corner of the predefined area, the width (in number of columns) of the predefined area, and the length (in number of rows) of the predefined area. In another possible embodiment, the initial data could include the list of coordinates (row and column in the matrix) of all the elements of the matrix that make up the predefined area.

[0053] The processing module 22 can thus determine, for each predefined zone (defined by some of the first data), a temperature information relating to the predefined zone concerned, obtained by taking into account all the temperature values ​​located in the predefined zone concerned.

[0054] The processing module 22, for example, determines the average of the temperature values ​​located in the relevant predefined area.

[0055] The processing module 22 can also determine the maximum value among the temperature values ​​located in the relevant predefined area.

[0056] The processing module 22 can also determine the minimum value among the temperature values ​​located in the relevant predefined zone. According to a possible embodiment, the aforementioned predefined zones are not defined by initial data as described above, but the determination of the temperature information relating respectively to the different predefined zones results from the programming of the processing module 22.

[0057] Furthermore, for each part of the environment (potentially moving) for which we wish to obtain at least one temperature information (relating therefore to an evolving set of temperature values), the processing module 22 stores (for example in a non-volatile, possibly rewritable memory):

[0058] - second data defining an area within the matrix;

[0059] - one or more third data points defining a range of temperature values;

[0060] - a first threshold and a second threshold.

[0061] In the example described here, the first threshold is strictly less than the second threshold. The area defined by the second data point (or predefined area) is the area of ​​the matrix corresponding to the region of the environment (here, the passenger compartment) in which the part of the environment in question is likely to be located.

[0062] For example, if the part of the environment concerned is the driver's face, the predefined area (defined by the given seconds) is an area (on the matrix) corresponding to the places (in the passenger compartment) where the driver's face can be located in the driving position (taking into account the different possible sizes of the driver, the different movements he can usually make and the different possible adjustment positions of the driver's seat).

[0063] Thanks to the processing performed in the following steps (identifying a set of values ​​meeting certain criteria), the predefined area (defined by the given seconds) can be chosen relatively broadly. For example, if the relevant part of the environment is the face of a rear passenger, the predefined area (defined by the given seconds) can extend over an area corresponding to the entire width of the rear seat.

[0064] In some embodiments, the predefined area (defined by the given seconds) can cover the entire matrix (the identification described below then being performed within the set of temperature values ​​in the matrix). As already mentioned previously regarding the first data, several ways are possible to define the predefined area using the given seconds. For example, when the predefined area is rectangular, the given seconds can include the coordinates (row and column in the matrix) of the upper left corner of the predefined area, the width (in number of columns) of the predefined area, and the length (in number of rows) of the predefined area. According to another possible embodiment, the given seconds can include the list of coordinates (row and column in the matrix) of all the elements of the matrix forming the predefined area.

[0065] The range of temperature values ​​can be chosen according to the part of the environment concerned and / or the phenomenon that one wishes to take into account or detect.

[0066] If the part of the environment in question is a part of the human body (such as a part of the body of a vehicle occupant) exposed to the elements (for example, an occupant's face or hand), the range of values ​​is defined, for example, by a lower limit between 20°C and 30°C and an upper limit between 33°C and 40°C. In the example described here, a lower limit of 28°C and an upper limit of 35°C are used, resulting in a range of values ​​between 28°C and 35°C.

[0067] If the part of the environment concerned is a part of the passenger compartment where it is desired to be able to detect a possible fire, the range of value is for example limited by a lower limit only, this lower limit being for example greater than 100 °C (or even 150 °C).

[0068] The third data point(s) mentioned above (defining the range of values) is (are) for example representative of the lower bound and / or the upper bound.

[0069] The first and second thresholds are defined based on the expected size of the environmental segment within the matrix (i.e., based on the physical dimensions of this environmental segment and the distance between this segment and the thermal sensor). As will become clear from the explanation that follows, the first and second thresholds are designed to bracket the number of matrix elements that typically correspond to the environmental segment in question. In the example described here, when the environmental segment is an occupant's face, the first threshold is between 5 and 10 (and is 8 in the example described) and / or the second threshold is between 15 and 30 (and is 20 in the example described). When the studied environmental segment is moving within the predefined area, the second threshold is generally strictly less than the number of values ​​in that predefined area.

[0070] The processing module 22 is configured (i.e. programmed for example when it is a processor) to identify, within the area of ​​the matrix defined above, a set of contiguous temperature values ​​in the matrix, included in the aforementioned range of values ​​and whose number is between a first threshold and a second threshold.

[0071] For example, we consider two temperature values ​​to be contiguous in the matrix when these two temperature values ​​are located on the same row of the matrix and in adjacent columns, or on the same column and in two adjacent rows.

[0072] When a set of temperature values ​​as defined above is identified, each temperature value in the set is contiguous with at least one other temperature value in the set.

[0073] In practice, the processing module 22 is, for example, designed to build such a set by scanning the temperature values ​​of the predefined area and, during this scanning:

[0074] - by detecting a temperature value within the range of values, then, iteratively:

[0075] - by adding to the set any temperature value within the range of values ​​and contiguous in the matrix to a temperature value already present in the set.

[0076] When all the temperature values ​​in the predefined area have been considered (scanned), the processing module 22 counts the number of elements (i.e., temperature values) in the constructed set:

[0077] - if this number is between the first threshold and the second threshold, this set is identified as a set of contiguous temperature values ​​in the matrix, within the range of values ​​and whose number is between the first threshold and the second threshold (we then consider that the part of the environment we are interested in is detected);

[0078] - if this number is not between the first threshold and the second threshold (that is, if the number of elements of the constructed set is strictly less than the first threshold or strictly greater than the second threshold), the constructed set is not considered as a set as defined above and we can therefore consider that the part of the environment in which we are interested has not been detected.

[0079] Figure 3 represents an example of a thermal image corresponding to a matrix of temperature values.

[0080] Temperature values ​​below the lower bound of the range are represented by pixels consisting of dots. Temperature values ​​between the lower and upper bounds (and therefore within the temperature range) are represented by pixels consisting of simple hatching. Temperature values ​​above the upper bound of the range are represented by crosshatching.

[0081] Region R1 contains a single pixel corresponding to a value within the specified range, and therefore does not meet the criterion regarding the number of values ​​in the set. Consequently, no set is identified for region R1.

[0082] The R2 region comprises 9 contiguous pixels corresponding to values ​​(therefore contiguous in the matrix) within the range of values, so that the set of values ​​corresponding to the R2 region is identified as a set of temperature values ​​contiguous in the matrix, within the range of values ​​and whose number is between the first threshold and the second threshold.

[0083] The processing module 22 is also designed to, when such a set of contiguous temperature values ​​in the matrix, within the range of values ​​and whose number is between the first threshold and the second threshold is identified, determine the temperature information sought based on the temperature values ​​of the identified set.

[0084] The processing module 22 determines, for example, the average of the temperature values ​​of the identified set (case where the temperature information sought is the average temperature of the part of the environment). The processing module 22 can also determine the maximum value among the temperature values ​​of the identified set (case where the temperature information sought is the maximum temperature of the part of the environment).

[0085] The processing module 22 can also determine the minimum value among the temperature values ​​of the identified set (case where the temperature information sought is the minimum temperature of the part of the environment).

[0086] The processing module 22 can thus determine several temperature information, this temperature information being able to relate to a predefined area (i.e. based on all the temperature information located in a predefined area, defined here by some of the first data mentioned above) or to an identified area (in real time) in accordance with the algorithm proposed above (for example among those that have just been indicated).

[0087] The processing module 22 produces, for example, between 20 and 50 such temperature information at each acquisition time (i.e., for each acquisition of a matrix of temperature values ​​within the measuring device 2).

[0088] The communication unit 24 is designed to transmit the temperature information determined by the processing module 22 to the electronic control unit 10 via the communication interface 6.

[0089] The aforementioned temperature information, which is inexpensive in terms of bandwidth, can be transmitted via a low-speed bus such as the local interconnected network (or LIN) used here.

[0090] In the aforementioned variant where a CAN type network is used, the advantage of low bandwidth cost of temperature information is retained, especially since such a communication bus can be shared between different vehicle systems.

[0091] The electronic control unit 10 is designed to receive (via the communication interface 6) the temperature information determined by the processing module 22 and to determine, based on the temperature information received, instructions (for example, setpoints) intended respectively for the ventilation unit 12 and / or the heating unit 14 and / or the air conditioning unit 16. The electronic control unit 10 is designed to send each determined instruction to the unit concerned (ventilation unit 12 or heating unit 14 or air conditioning unit 16).

[0092] For each piece of information relating to an area identified (in real time) by the measuring device 2 (i.e. to an evolving set of temperature values), the processing module 22 can also be designed to, when no set of contiguous temperature values ​​in the matrix, included in the range of values ​​and whose number is between the first threshold and the second threshold is identified, set the temperature information concerned to a predefined value indicative of an absence of detection of the part of the environment concerned.

[0093] In this case also, the temperature information is transmitted to the electronic control unit 10 by the communication unit 24 via the communication interface 6 in order to inform the electronic control unit 10 of the absence of detection and therefore of the unavailability of the information sought.

[0094] Figure 4 is a flowchart showing the main steps of a process that can be implemented in the system of Figure 1.

[0095] The process begins with a step E2 of production of a matrix of temperature values ​​by the acquisition module 20, based on measurements made by the thermal sensor equipping the acquisition module 20.

[0096] The process then includes a step E4 of determination, by the measuring device 2 (specifically here by the processing module 22) and for each of a plurality of predefined areas of the matrix (areas defined here by the first data), of a temperature information obtained by taking into account all the temperature values ​​located in the predefined area concerned.

[0097] This temperature information can be the average of the temperature values ​​located in the relevant predefined area, or the maximum value among the temperature values ​​located in the relevant predefined area, or the minimum value among the temperature values ​​located in the relevant predefined area.

[0098] The process continues with an E6 identification step, within another predefined area of ​​the matrix (area defined here by the second data stored in the processing module 22 for the part of the environment concerned), of a set of contiguous temperature values ​​in the matrix, within a predefined range of values ​​(range defined here by the third data stored in the processing module 22 for the part of the environment concerned) and whose number is between the first threshold and the second threshold (this first threshold and this second threshold being stored here in the processing module 22 for the part of the environment concerned).

[0099] This section describes the implementation of a step to determine such temperature information (for example, an average temperature, a maximum temperature, or a minimum temperature) for a specific part of the environment (here, the vehicle's interior). This specific part could be, for example, the face of an occupant of the vehicle (possibly the driver's face). Other steps of the same type can be implemented, either in parallel or at separate times, for another part of the environment or for other temperature information.

[0100] If an assembly is identified at step E6 (i.e. in case of identification, arrow P in figure 4), the process continues with a step E8 of determining the temperature information based on the temperature values ​​of the identified assembly.

[0101] If the temperature information sought is the average temperature of the relevant part of the environment, the temperature information determined in step E8 is the average of the temperature values ​​of the identified set.

[0102] If the temperature information sought is the minimum temperature of the relevant part of the environment, the temperature information determined in step E8 is the minimum value among the temperature values ​​of the identified set.

[0103] If the temperature information sought is the maximum temperature of the relevant part of the environment, the temperature information determined in step E8 is the maximum value among the temperature values ​​of the identified set.

[0104] If no set as defined above is identified in step E6 (i.e., in the absence of identification of such a set, arrow N in figure 4), the process includes a step E10 of setting the temperature information to a predefined value indicative of the absence of detection of the relevant part of the environment. In both cases considered above, the process then includes a step E12 during which the processing module 22 commands the transmission (here by the communication unit 24) of the temperature information (determined in steps E4, E8 and / or E10) to the electronic control unit 10 via the communication interface 6.At each E12 transmission step (carried out following an E2 production step of a matrix of values), the number of temperature information transmitted is, for example, less than 50, here between 20 and 50, in order to reduce the amount of data transmitted and the subsequent processing carried out by the electronic control unit 10.

[0105] The process then includes a step E14 of determining instructions and / or setpoints by the electronic control unit 10, based on the temperature information received by the electronic control unit 10. The electronic control unit 10 may, however, take into account other parameters to determine these instructions and / or setpoints.

[0106] The process finally includes a step E16 of sending the determined instructions and / or guidelines to the ventilation unit 12 and / or the heating unit 14 and / or the air conditioning unit 16.

Claims

Demands

1. Electronic system comprising a measuring device (2) and an electronic control unit (10) connected by means of a communication interface (6), in which the measuring device (6) comprises: - an acquisition module (20) configured to produce a matrix of temperature values ​​based on measurements taken by a thermal sensor; and - a processing module (22) configured to determine, for each of a plurality of predefined areas of the matrix, a temperature information obtained by taking into account all the temperature values ​​located in the predefined area concerned, and in which the measuring device (2) is configured to transmit the temperature information to the electronic control unit (10) via the communication interface (6).

2. Electronic system according to claim 1, wherein the electronic control unit (10) is configured to send instructions to a heating or ventilation or air conditioning unit (12; 14; 16).

3. Electronic system according to claim 1 or 2, wherein the number of elements in the matrix is ​​greater than 500.

4. Electronic system according to any one of claims 1 to 3, wherein the measuring device is configured to transmit, for each acquisition of a temperature value matrix, a number of temperature information less than 50.

5. Electronic system according to any one of claims 1 to 4, wherein the communication interface (6) has a throughput of less than 20 kbit / s.

6. Electronic system according to any one of claims 1 to 5, wherein the communication interface (6) is a local interconnected network.

7. An electronic system according to any one of claims 1 to 6, wherein the processing module (22) is configured to identify a set of temperature values ​​from the matrix and to determine at least one temperature information based on the temperature values ​​of the identified set.

8. An electronic system according to claim 7, wherein the processing module (22) is configured to identify said set of values ​​by identifying contiguous temperature values ​​in the matrix, within a predefined range of values ​​and the number of which is between a first threshold and a second threshold.

9. Electronic system according to any one of claims 1 to 8, wherein the transmitted temperature information includes at least an average of the temperature values ​​located in one of said predefined zones.

10. A method for transmitting temperature information, comprising the following steps: - production (E2), by a measuring device (2), of a matrix of temperature values ​​based on measurements made by a thermal sensor; - determination (E4), by the measuring device (2) and for each of a plurality of predefined areas of the matrix, of a temperature information obtained by taking into account all the temperature values ​​located in the predefined area concerned; - transmission (E12) of temperature information to an electronic control unit (10) via a communication interface (6) linking the measuring device (2) and the electronic control unit (10).

11. A computer program comprising instructions executable by a processor and designed to implement a process according to claim 10 when these instructions are executed by the processor.

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