Preheating Method of Post-Processing Device

Abstract

A preheating method is provided for controlling the temperature rise of an aftertreatment device (100) of a vehicle that is at least partially driven by an internal combustion engine. The preheating method comprises a starting step (6) of preheating the aftertreatment device (100) to a threshold heating power level (22, 44), and at least one cycle (40, 42) following the starting step (6), the cycle (40, 42) comprising a step (7, 8) of detecting a user action included in a list (103) of key actions representing a request to start the vehicle, and a step (9, 10) of increasing the heating power level to a higher heating power level when a key action (103) representing a request to start the vehicle is detected.

Description

Technical Field

[0001] The present invention relates to the field of pollution removal of vehicles driven at least in part by an internal combustion engine, i.e., for example, hybrid vehicles or pure thermal vehicles. More particularly, the present invention relates to a method for preheating a device for post-treatment of pollutant emissions from the engine, configured to control the temperature rise of a post-treatment device.

Background Art

[0002] Automobile manufacturers aim to reduce pollutant emissions from internal combustion engines, particularly emissions of unburned hydrocarbons (HC), nitrogen oxides (NOx), nitric oxide (NO), and carbon dioxide (CO2), which is a greenhouse gas, for those vehicle models driven at least in part by the above internal combustion engine.

[0003] One well-known method of reducing the emission of pollutant molecules contained in the combustion gases of these engines into the outside air is to add a post-treatment device to the vehicle exhaust circuit. For example, these systems can be exhaust catalytic converters that treat exhaust gases, particularly in the case of gasoline engines, three-way catalytic converters that oxidize unburned hydrocarbons and carbon monoxide and reduce nitrogen oxides. Currently, in-vehicle catalytic converters available on the market need to reach a specific temperature, which can be expressed as the ignition temperature, in order to reach their maximum capacity when converting pollutant molecules into less harmful ones, i.e., to achieve sufficient efficiency. Generally, the temperature required for a catalytic converter to operate properly is about 450°C.

[0004] Therefore, in order to reach the priming temperature of the post-treatment system as soon as possible after the vehicle is started, the in-vehicle post-treatment system needs to be preheated. As is well known, manufacturers perform this preheating operation by adding an electrical device such as a heating grid to the catalytic converter. These grids are used to raise the temperature of the catalytic converter.

[0005] The electrical energy used to activate the pollution control system by these preheating means is taken from the battery, and the battery naturally has a certain storage capacity.

[0006] As described above, it is known to perform a preheating operation so that the catalytic converter becomes effective immediately after the vehicle is started. It is known to anticipate the preheating operation so that the user is not forced to wait unnecessarily long before starting their own vehicle. The preheating operation starts at a specific point in time, for example, when the user approaches the vehicle.

[0007] Generally, the user starts the vehicle and its internal combustion engine immediately after the preheating stage of the aftertreatment device. Thereafter, the battery can be recharged by an alternator or a similar system. Such a system is known in the prior art, especially in Patent Document 1.

[0008] One drawback of such a system is the risk that the aftertreatment device will be preheated even if the vehicle, which is at least partially driven by the internal combustion engine, is not subsequently started. This can generally be the case when the user follows the conventional starting steps (unlocking the vehicle, getting into the driver's seat, etc.) but does not actually start the vehicle. In this case, the battery cannot be recharged as in a conventional scenario. Repeated occurrences of this scenario will result in a large amount of energy being taken from the battery, leading to a significant decrease in the battery level and ultimately a reduction in the preheating capacity.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Summary of the Invention

[0010] The object of the present invention is to provide a solution to the above technical problem by proposing a method for preheating a post-treatment device and enabling the temperature rise to be adapted to a future operating mode. By this method, the preheating of the post-treatment device can be optimized.

[0011] Accordingly, an object of the present invention is a preheating method for controlling the temperature rise of a post-treatment device of a vehicle powered at least in part by an internal combustion engine, the preheating method comprising a starting step of preheating the post-treatment device to a threshold heating power level, with at least one cycle following the starting step, the cycle comprising a step of detecting a user action included in a list of key actions representing a request to start the vehicle, and a step of raising the heating power level to a higher heating power level when a key action representing a request to start the vehicle is detected.

[0012] The starting step is triggered by the detection of a predetermined situation representing a request to use the vehicle. This predetermined situation can consist, for example, of the relationship between the vehicle and the user when the user approaches the vehicle and their remote unlocking key or their phone is detected, or when the user brings their hand close to the door handle. Specific sensors may be used to detect this predetermined situation, or sensors may already be installed in the vehicle. The predetermined situation may consist, for example, of an exact moment in the case of the daily operation of the starting step. For example, if the vehicle is unlocked at a specific time every day, this exact moment may be set in the system or may be acquired when the vehicle is used.

[0013] It should be noted that the predetermined situation is an indication of the intention to use the vehicle, that is, the intention or action to enter the vehicle or the intention to sit in the driver's seat, but not an indication of the intention to start.

[0014] According to the present invention, an action representing such a starting request is determined during one cycle following the starting step, and at least one step for detecting this action and one step for raising the temperature of the post-treatment device are performed.

[0015] The detection step executes means capable of detecting one or more key actions from a list of key actions representing a starting request. These key actions representing a starting request are detected by means capable of detecting one or more actions taken by the user in relation to the vehicle. By way of example, a key action representing a request to start the vehicle can be fastening the seat belt.

[0016] As described above, by the raising step, the heating power level can be raised to an intermediate level and approaches or reaches the maximum heating power level.

[0017] It should be noted that the method comprises at least one cycle following the starting step, which may comprise a plurality of consecutive cycles. The end of the raising step of the first cycle corresponds to triggering the detection step of the subsequent cycle. Each of these consecutive cycles has an intermediate heating power level, and the intermediate heating power level of a cycle is higher than the heating power level of the previous cycle or a threshold heating power level. By the continuation of these cycles, the heating power level can reach the maximum heating power level in successive steps.

[0018] Preheating of the post-treatment device is performed by a thermal system such as an electric heating grid powered by a battery. It is understood that the maximum heating power level corresponds to an operating mode that gives the maximum thermal energy that the thermal system can supply.

[0019] Advantageously, the preheating method performs a starting step, at least one cycle comprising at least one detection step taking into account user actions, and a rising step. The configuration of the preheating method with the rising in successive stages of the thermal power level facilitates dealing with the case where the user decides not to start or to delay the starting of the vehicle while being present in the passenger compartment, departing from the conventional vehicle starting method, thereby avoiding the maximum energy loss due to a meaningless complete preheating of the aftertreatment device. The energy loss will be limited to an intermediate heating level reached by the system. In other words, the step-by-step rise of the heating level as described above enables approaching the maximum power level and activates the aftertreatment device when the vehicle is started. On the other hand, it shows the possibility of the user delaying or aborting the starting of the vehicle when the level reached during preheating has not yet reached the maximum, thereby saving the energy consumed by the thermal system. This will reduce the energy supplied by the alternator to the battery at startup, delaying the depletion of the battery and reducing the energy consumption. Thereby, as long as the alternator takes in energy from the internal combustion engine to recharge the battery, the fuel consumption of the engine decreases, and thus the emission of its carbon dioxide, which is a greenhouse gas, decreases.

[0020] According to another feature of the invention, the at least one cycle is a final cycle having a final detection step and a final rising step at the end of which the heating power level becomes equal to the maximum heating power level.

[0021] In other words, the final cycle is the last cycle executed by the preheating method, and this final cycle enables reaching the maximum heating power level representing the maximum thermal energy that can be supplied by the thermal system. According to the invention, this final cycle is not triggered immediately, but at least following the execution of the starting step that contributed to raising the heating power to a threshold, such that the maximum heating power is not triggered and energy savings are achieved if no key action indicating the intention to start, which should be detected during the final detection step, is detected.

[0022] According to another feature of the present invention, after the start-up step, a plurality of consecutive cycles having at least one intermediate cycle performed between the start-up step and the final cycle are executed. The intermediate cycle includes an intermediate detection step and an intermediate increase step that enables the heating power level to change from a threshold heating power level to an intermediate heating power level. It is understood that the intermediate heating power level is a value higher than the threshold heating power level and lower than the maximum heating power level. When there are a plurality of intermediate cycles, continuous reaching of a plurality of intermediate heating power levels is possible in the process of the method, the intermediate heating power levels form a stepwise increase in the heating level independently of each other, and the intermediate heating power level reached at the end of the intermediate stage is higher than the intermediate heating power level reached at the start of the intermediate stage.

[0023] The number of intermediate cycles and the type of key action representing the start-up request that triggers this intermediate cycle are predefined by the manufacturer, and each intermediate cycle has its own intermediate heating power level.

[0024] In the first case, the preheating method may not include an intermediate cycle, and the method includes only a start-up step and a final cycle. In this case, only one cycle, that is, only the final cycle, is performed after the start-up step. The increase step is such that the intermediate level referred to becomes equal to the maximum heating power level.

[0025] In the second case, the preheating method may include at least one intermediate cycle, and the preheating method includes a start-up stage, one or more intermediate cycles, and finally a final cycle. In this case, after the start-up step, a plurality of cycles including the final cycle follow one another. The increase step is such that the heating power level is continuously increased from the threshold heating power level reached after the start-up step to the maximum heating power level, so that the intermediate level approaches the maximum heating power level with a plurality of consecutive intermediate heating power levels.

[0026] According to an optional feature of the present invention, the predetermined situation that can trigger the startup step is the detection of the proximity of the user to the vehicle. According to an optional feature of the present invention, the key actions that can represent a request to start the vehicle, which can be detected in the intermediate cycle, consist of actions related to the positioning of the user in contact with the vehicle, such as opening the vehicle door or taking a seat in the driver's seat, or the positioning of the user inside the vehicle.

[0027] The manufacturer defines which key actions are indications of a startup request and whether they represent the startup of the intermediate cycle or the startup of the final cycle. The database groups together all the key actions representing the startup request, and this database is associated with the control unit of the thermal system. The key actions representing the startup command are implemented in the database by the manufacturer. The key actions representing the request to start are associated with the heating power level of the thermal system associated with the post-processing device, and the value of this heating power is selected in relation to the proximity of the associated key action to the actual startup of the vehicle. More specifically, the heating power level corresponding to an action estimated to be very close in time to the actual startup of the vehicle is high and close to the maximum heating power level. On the other hand, the heating power level corresponding to an action estimated to be far in time from the actual startup of the vehicle is low but higher than the threshold heating power level to achieve a gradual increase. An action representing a request to start that is considered not to be the closest to the actual startup can consist, for example, of opening the door. On the other hand, an action representing a request to start that is considered to be the closest to the actual startup can consist, for example, of detecting a gesture by the user in the direction of the starting device. By ordering the key actions representing the request to start, it becomes possible to gradually approach the maximum heating power level, while avoiding generating the maximum heating power level for a key action representing a request to start that is not the closest to the start, such as opening the driver's seat door, thereby limiting the number of times the maximum heating power is supplied when the user does not actually start the vehicle.

[0028] According to another feature of the present invention, the key action representing the request to start the vehicle that can be detected in the final cycle consists of the hand position within the area of the vehicle starting device.

[0029] Alternatively, the last key action representing the request to start, i.e., the display key action that can be detected in the final cycle, may be independent of the action associated with the starting device. For example, it may consist of the user operating the clutch or brake before starting. The last key action representing the request to start is selected by the manufacturer.

[0030] According to a further feature of the present invention, the verification step is configured to monitor the actual start of the vehicle over a predetermined period and starts when the maximum heating power level is reached.

[0031] In other words, following the final cycle, a verification phase over a predetermined period is triggered. The predetermined period is preselected by the manufacturer and can be adjusted by implementing the user's learning about starting the vehicle. During this time, if the starting device is activated, the preheating method stops.

[0032] According to another feature of the present invention, the verification step includes detecting the temperature of the aftertreatment device when the actual start is not detected. This detects whether the aftertreatment device has reached the priming temperature.

[0033] The present invention also relates to a preheating system configured to execute the aforementioned preheating method for controlling the temperature rise of an aftertreatment device of a vehicle at least partially driven by an internal combustion engine. The preheating system includes at least one thermal system configured to raise the temperature of the aftertreatment device, detection means configured to detect a key action representing a request to start the vehicle, and a control unit configured to lead an increase in the heating power level of the thermal system in response to the detection of the key action.

[0034] The preheating system includes at least one thermal system, such as a heating grid, configured to supply heat to the post-treatment device by an appropriate power source.

[0035] The preheating system includes a control unit configured to correct the level of heating power assigned to the thermal system in response to start request detection information, and the start request detection information is an indication of a key action of a start request included in the database of the control unit.

[0036] In particular, the post-treatment device may be included in at least a portion of the vehicle exhaust pipe.

[0037] According to another feature of the present invention, the detection means includes at least one heterodyne sensor configured to detect the presence in the region near the starting device by the voltage difference between sensors.

[0038] The preheating system includes at least one heterodyne sensor configured to determine the distance between the sensor and the driver's hand, the position of the hand is not known, and this detection gives a range of possible hand positions. By this detection, it is possible to detect the direction of the hand and thus detect the intention of the action.

[0039] According to a further feature of the present invention, three heterodyne sensors are positioned at a predetermined distance from each other around the region of the starting device.

[0040] The preheating system may include three heterodyne sensors configured to determine the position of the hand in space. This position is determined by triangulating the information on the presence of the user's hand within the detection area common to the sensors.

[0041] Other features, details and advantageous effects of the present invention will become clearer by reading, on the one hand, the following detailed description and, on the other hand, the examples of embodiments given by way of illustration and not limitation with reference to the accompanying drawings.

Brief Description of the Drawings

[0042]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0043] The features, modifications, and various embodiments of the present invention may be combined with each other in various ways, provided that they are not contradictory or mutually exclusive. In particular, when the selection of features provides a technical effect and / or is sufficient to distinguish the present invention from the prior art, it is possible to conceive of a modification of the invention having only the selection of the features described below, independent of the other features described.

[0044] The present invention relates to an apparatus for preheating an aftertreatment system of a motor vehicle. In order to comply with increasingly stringent pollution prevention standards for vehicles that are at least partially driven by an internal combustion engine, vehicle manufacturers need to find ways to reduce the amount of pollutant molecules (such as HC, CO, NOx, etc.) that these vehicles can generate. To achieve this, the exhaust system is adapted to a post-treatment device such as a catalytic converter that reduces the release of these pollutants into the outside air by filtering the combustion gases discharged from the vehicle engine. Furthermore, vehicle manufacturers aim to minimize the emission of CO2, which is a normal product of engine combustion and also a greenhouse gas.

[0045] The post-treatment device also includes a thermal system, and its function is to raise the temperature of the post-treatment device as needed without starting the vehicle, and perform a preheating operation so that the post-treatment device reaches an optimal operating temperature, for example, about 450 °C as soon as the vehicle is started. The thermal system can be an electrical device driven by the vehicle battery, such as a heating grid.

[0046] Figure 1 shows a preheating system of a post-treatment device according to the present invention configured to perform the preheating method described below.

[0047] The preheating system of the post-treatment device 100 includes a thermal system 101 and a control unit 102 configured to drive the thermal system 101 in particular, and also includes detection means 104 that can detect a key action AC representing a start request and communicate with the control unit 102.

[0048] The control unit 102 is configured to drive the thermal system 101. More specifically, according to the present invention, the control unit 102, on the one hand, causes the ignition of the thermal system 101, resulting in steps for starting the preheating method of the post-treatment device 100, and on the other hand, is configured to control the level of heating power generated by the thermal system 101.

[0049] One advantageous effect of the present invention is that when the vehicle is started to ensure its efficiency, the temperature rise of the aftertreatment device 100 is modulated during the preheating stage to ensure that the aftertreatment device 100 reaches an appropriate temperature. On the other hand, when the vehicle is not actually started, the situation where all the power is supplied to the thermal system 101 to supply the maximum heat to the aftertreatment device 100 is avoided.

[0050] The control unit 102 is specific to the thermal system 101 of the present invention and may be specialized for controlling the thermal system 101 to enable preheating of the aftertreatment device 100. Alternatively, the control unit 102 may be integrated into the vehicle's central computer.

[0051] The control unit 102 includes a database in its memory, in which a list 103 of key actions indicating the intention to start is implemented, and the database is implemented together with the heating power level of the thermal system 101 associated with each key action AC indicating the intention to start. In other words, the control unit generates a command to control the thermal system at a given heating power level according to the display key action AC detected and identified by the control unit. The number of key actions representing start commands present in the list implemented in the database is selected by the manufacturer and can thus vary between vehicle applications.

[0052] The detection means 104 is configured to detect the occurrence of a key action AC representing a start command. Specific detection means are required for each key action indicating the intention to start. The detection of key actions representing a start request can also be performed by diverting detection means already present in the vehicle, such as a seating sensor.

[0053] As described below, the operation of such a control unit enables the intermediate heating power level to be triggered for the progressive temperature rise of the post-treatment device 100, and the intermediate heating power level has a heating level that traverses from the threshold heating level obtained after the start-up step that enables the first stage of the temperature rise to the maximum heating level obtained after the final cycle. According to an embodiment, the control unit includes in its database only one key action indicating the intention to start. And the preheating method includes only the start-up stage and the final cycle triggered by the detection of this single key action. As a non-limiting example, as detailed below, this single key action indicating the requirement to start can be the presence of the driver's hand near the start-up device 2. In other embodiments, the control unit includes in its database a plurality of key actions indicating the requirement to start, which requires a plurality of detection means.

[0054] Various display key actions and associated detection means are selected by the manufacturer according to the presence of these detection means on the vehicle and / or the validity of the action considered to indicate the requirement to start. And the preheating method includes the start-up stage, the final cycle that can also be started by detecting the presence of the driver's hand near the start button here, and at least one intermediate cycle that can be generated by detecting other key actions.

[0055] The occurrence of a predetermined situation causes the step of starting the preheating method to start. This predetermined situation can be an automatic situation, for example, a daily situation, or a situation that occurs somewhat away from the vehicle, for example, the start of preheating by the user via an appropriate application.

[0056] The key action indicating the requirement to start can be, but is not limited to, a link between the user and the vehicle when the user is outside the vehicle, such as a user action on the vehicle key or the detection of the user's hand on the vehicle door handle, or a link between the user and the vehicle, such as the opening of the vehicle door or the presence of the user on one of the vehicle seats.

[0057] The detection means used to detect these key actions can be means specialized for these detections, or existing means such as door opening detection sensors, seat belt buckle detection sensors, or pressure sensors present in the driver's seat that already exist in most current vehicles.

[0058] It should be noted that each of the actions given only as examples as key actions representing a start request can also constitute the above-mentioned predetermined situation, that is, a situation that triggers the start-up stage of the preheating method.

[0059] Figure 1 also shows a series of steps in a preheating method according to an aspect of the present invention executed by the preheating device described above. When a key action AC representing a start request is detected by the detection means 104, the detection information is transmitted to the control unit 102. The control unit 102 analyzes the validity of the received data by comparing the detection information, in particular, with a list 103 of display key actions stored in a database associated with the control unit 102. Then, the control unit identifies the display key action and the associated heating power level.

[0060] After this analysis, the control unit 102 communicates a heating power level correction command to the thermal system 101 to enable correction of the temperature of the post-processing device 100.

[0061] Figures 2 and 3 show in more detail the first mode of execution of the preheating method. In the first mode, two main stages occur, which include a start-up stage 6 and a final cycle 40 including a final detection stage 7 and a final increase stage 9 of the heating power level of the thermal system.

[0062] As shown in the flowchart of Figure 2, the preheating method starts with a start-up step 6 that is initiated by the occurrence of a predetermined situation. The start-up step sets the heating power level of the thermal system to a threshold power level.

[0063] In the first embodiment of this preheating method, the final cycle 40 starting at the above-described final detection step 7 follows the startup step. If no key action AC indicating a startup request is detected (23), the heating power level does not change and a new final detection step 7 is started. If a key action AC indicating a startup request is detected (24), the final rise step 9 is started and the control unit sets the thermal system to the maximum heating power level 26.

[0064] Figure 3 shows the gradual change in the heating power level of the thermal system 101 during the preheating method, where the change is expressed here as a percentage relative to the maximum heating level, particularly together with the threshold heating level 22 and the maximum heating level 26. Curve 20 shows the temperature of the post-treatment device 100 as a function of time and heating power level from the start of the preheating method.

[0065] As can be seen from Figure 3, the startup step 6 drives the control unit 102 to operate the thermal system 101 at a threshold heating level 22 on the order of 40% of the maximum heating power of the thermal system, whereby the temperature of the post-treatment device 100 gradually increases with time due to the first significant rise 28 in curve 20. When a key action indicating a startup request is detected during the final detection step 7 that starts the final cycle 40, the final rise step 9 triggers an increase to the maximum level 26 of the heating power level. Thus, the temperature of the post-treatment device 100 rises more steeply with time to form a final rise gradient 30 visible on curve 20, whereby the post-treatment device 100 reaches the desired temperature. The final cycle 40 in this method is represented by the succession of the final detection step 7 and the final rise step 9.

[0066] Figures 4 and 5 show a second embodiment of the preheating method. The preheating method here comprises at least three main stages including a startup stage 6 and a final cycle 40 similar to those described above, and at least one intermediate cycle 42 between the startup stage and the final cycle, the intermediate cycle 42 comprising an intermediate detection stage 8 and an intermediate rise stage 10.

[0067] As shown in the flowchart shown in FIG. 4, the preheating method according to the second embodiment, like the first embodiment, is also started here by the occurrence of a predetermined situation, and starts with a startup step 6 in which the heating power level is set to the threshold power level 22, which constitutes the first heating power increase stage. Different from the first embodiment, the final cycle 40 does not directly follow the startup step, but at least one intermediate cycle 42 between the startup stage 6 and the final cycle 40 follows. By each of these intermediate cycles, the heating power level of the thermal system can be gradually increased from the threshold power level 22 through the intermediate power level to the maximum power level.

[0068] In the second embodiment of the preheating method, an intermediate cycle 42 starting with an intermediate detection step 8 follows the startup step. If there is no detection (32) of the key action AC representing the startup request, the heating power level does not change, and a new intermediate detection step 8 is started. If the key action AC representing the startup request is detected (34), an intermediate increase step 10 is started, and the control unit drives the heating system to the intermediate threshold level (44).

[0069] Therefore, the succession of the intermediate detection step 8 and the intermediate increase step 10 constitutes an intermediate cycle 42 specific to this second embodiment, and other intermediate cycles having a new intermediate detection step and a new increase step following the intermediate increase step may follow.

[0070] If the detection 34 of the key action AC representing the startup request is related to the key action AC existing in the list 103, which the manufacturer has determined to be closest to actually starting the vehicle, the relevant or one of the intermediate cycles 42 is extended by the final cycle 40. As described above, the final cycle 40 is triggered by setting the heating power level of the thermal system to the maximum power level 26.

[0071] The second embodiment is also worth noting in that, as described above, it includes a verification step 46 that starts when the maximum heating power level 26 is reached.

[0072] The verification step 46 consists of a confirmation stage that verifies whether the vehicle has actually started, for example, by confirming that an action has been performed on the starting device 2, such as rotating the vehicle key over a predetermined period since the verification step started. If it is detected that the starting device 2 has been turned on, a first operation 48 to stop the preheating method is generated. On the other hand, if it is detected that the starting device has not been turned on, a second operation 50 to confirm that the aftertreatment device is turned on by measuring the temperature of the aftertreatment device is generated.

[0073] If the first result 54 indicates that the aftertreatment device 100 has not reached its priming temperature, the heating power level is maintained at maximum and the second operation is looped until the priming temperature is reached. Alternatively, if the second result 56 indicates that the aftertreatment device 100 has reached its priming temperature, the heating power level is reduced to a low level that can be the threshold heating power level 22 or the intermediate heating power level 44. Such a reduction to a low heating power level reduces the power consumption of the thermal system 101 while allowing the thermal inertia to be maintained within the aftertreatment device 100.

[0074] Although the verification step 46 has been described only for the second embodiment, it should be noted that the verification step 46 is also executable in the first embodiment of the preheating method without departing from the background of the present invention.

[0075] FIG. 5 shows the rate of change of the heating level of the thermal system during the preheating method, where the rate of change is expressed here as a percentage of the maximum heating level, particularly by the threshold heating level 22, the intermediate heating level 44, and the maximum heating level 26. Curve 60 shows the temperature of the aftertreatment device 100 as a function of time from the start of the preheating method and the heating power level.

[0076] As can be seen from FIG. 5, start-up step 6 drives the control unit 102 to operate the thermal system 101 at a first threshold heating level 22 on the order of 30% of the maximum heating power of the thermal system, whereby the temperature of the post-treatment device 100 gradually increases with time by a first significant rise 62 on curve 60 that sets the system to the first temperature level. When a key action representing a start-up request is detected during the intermediate detection step 8 of the intermediate cycle 42, the intermediate rise step 10 triggers an increase in the intermediate threshold heating power level 44, in this case to 70% of the heating power level. This completes the first intermediate cycle 42. This increase in power results in a steeper temperature rise of the post-treatment device 100, and this rise 64 becomes prominent on curve 60 of FIG. 5. The final cycle 40 ends this preheating method 4 with the temperature of the post-treatment device 100 rising as steeply as possible on curve 60 of FIG. 5 by increasing the heating power level to its maximum heating power level 26.

[0077] The preheating method may include a plurality of intermediate cycles 42 between the start-up step 6 and the final cycle 40. The second embodiment is non-limiting in terms of the possible number of intermediate cycles 42, and the number of intermediate cycles 42 between the start-up step 6 and the final cycle 40 is related to the display key action detected and reported to the control unit.

[0078] The power level assigned to the thermal system 101 during various stages related to the type of key action AC representing a start-up request may vary in relation to the learning method executed by the control unit. In other words, to optimize the energy cost for subsequent preheating operations and in particular to optimize the different heating thresholds associated with the detection of the key action AC, the last cycle and the resulting energy cost executed during the previous preheating operation are planned to be recorded.

[0079] With reference to FIGS. 6 and 7, an example of a detection system will be described here. It is understood that this example using at least one heterodyne sensor should be considered a non-limiting example of the present invention.

[0080] At least one heterodyne sensor comprises a pair of oscillators having a variable-frequency oscillator with an antenna and a fixed-frequency oscillator without an antenna. The frequency of the variable-frequency oscillator can change when the user's hand passes through the detection region of the variable-frequency oscillator antenna.

[0081] When nothing interferes with the detection region of the antenna, the frequency of the variable-frequency oscillator remains the same, i.e., substantially equal to the frequency of the fixed-frequency oscillator. When the body, particularly the user's hand, enters the detection region of the antenna, the frequency of the variable-frequency oscillator changes due to the body. The frequency of each oscillator is calculated in a dedicated computer, and the output signal calculated there changes in relation to the frequency of each oscillator, particularly in relation to the variation in the frequency of the variable-frequency oscillator. The analysis of the output signal reveals the distance between the body and the sensor and gives the range of possible body positions relative to the heterodyne sensor.

[0082] FIG. 6 shows an embodiment in which a single heterodyne sensor 66 is used. In this embodiment, the heterodyne sensor 66 is located near the starting device 2. When the driver's hand is within the detection region 68 of the sensor 66, the heterodyne sensor 66 can determine the distance between the hand and the starting device. The result is information about the position of the user's hand relative to the start button. The control unit can calculate this information in its original form by, in particular, triggering the operation of the thermal system when the distance between the hand and the start button is less than a distance threshold, or in a more analytical way, taking into account the gradual change in this distance value between the user's hand and the starting device, particularly triggering the operation of the thermal system when the distance below a certain threshold tends to decrease.

[0083] FIG. 7 shows a modified example in which three heterodyne sensors 70 are used and distributed around the starting device 2. By way of example, the first heterodyne sensor is disposed substantially in the region of the steering wheel, and the second and third heterodyne sensors are disposed on the dashboard at a predetermined distance from each other. Each heterodyne sensor operates as described above and, when a hand is detected, i.e., when the hand is within the detection area 68 around the heterodyne sensor, returns information to the control unit. By using three heterodyne sensors 70, it is possible to perform triangulation of the hand position and thereby obtain highly accurate information without the need to dispose a sensor with respect to the start button as described above.

[0084] The present invention described above achieves its stated objectives and makes it possible to provide a method for preheating a post-treatment device in successive temperature stages. The heating power level varies throughout the method following the start-up step and when a key action representing a request to start the vehicle is detected. Thus, according to the present invention, the preheating method is particularly promising in the following respects. It reduces CO2 production on a larger scale by avoiding waste of electrical energy from the battery during false starts and by reducing the resistance of the alternator used to recharge the battery once the vehicle has started. The preheating method is also promising in the following respect. It takes into account the thermodynamics of the post-treatment device material because excessive and repeated heating of the post-treatment device can have an adverse effect on the post-treatment device material. Variations not described herein can be implemented without departing from the context of the present invention, provided that the present invention is adapted to the step of increasing the heating level in successive stages.

Claims

1. A preheating method for controlling the temperature rise of an aftertreatment device (100) of a vehicle driven at least partially by an internal combustion engine, comprising: a starting step (6) of preheating the aftertreatment device (100) at a threshold heating power level (22, 44); and at least one cycle (40, 42) following the starting step (6), the cycle (40, 42) comprising: a step (7, 8) of detecting a user action included in a list (103) of key actions representing a request to start the vehicle; and a step (9, 10) of increasing the heating power level to a higher heating power level when a key action (103) representing a request to start the vehicle is detected.

2. The preheating method according to claim 1, wherein at least one of the cycles is a final cycle (40) having a final detection step (7) and a final increase step (9) at the end of which the heating power level becomes equal to the maximum heating power level (26).

3. After the starting step, a plurality of consecutive cycles are executed having at least one intermediate cycle (42) performed between the starting step (6) and the final cycle (40), the intermediate cycle (42) comprising an intermediate detection step (8) and an intermediate increase step (10) of increasing the heating power level from the threshold heating power level to an intermediate heating power level (22, 44). The preheating method according to claim 1.

4. The key action (103) representing a request to start the vehicle, which is detectable in the intermediate cycle (42), is an action related to ignition or the user's positioning within the vehicle. The preheating method according to claim 1.

5. The key action (103) representing a request to start the vehicle, which is detectable in the final cycle (40), consists of the position of the hand within the area of the vehicle starting device (2). The preheating method according to claim 2.

6. The verification step (46) is configured to detect the actual start of the vehicle over a predetermined period and starts when the maximum heating power level (26) is reached. The preheating method according to claim 1.

7. The verification step (46) comprises detecting the temperature of the aftertreatment device (52) when the actual start is not detected. The preheating method according to claim 6.

8. A preheating system configured to execute the preheating method according to claim 1, which aims to control the temperature rise of a post-treatment device (100) of a vehicle driven at least partially by an internal combustion engine, at least one thermal system (101) configured to raise the temperature of the post-treatment device (100), detection means (104) configured to detect a request to start the vehicle, and a control unit (102) configured to lead an increase in the heating power level of the thermal system (101) in response to the detection of the key action. A preheating system comprising:

9. The detection means (104) is at least one heterodyne sensor (66), and the preheating system according to claim 8, comprising a heterodyne sensor (66) configured to detect the presence in a region near the starting device by a voltage difference applied to the heterodyne sensor.

10. The preheating system according to claim 9, wherein three heterodyne sensors (70) are positioned at a predetermined distance from each other around the region of the starting device (2).

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