FR2755261A1 - Simplified user control of temperature inside vehicle cabin - Google Patents

Abstract

The automatic control circuit (CC) has a control (41) where the user can set the desired cabin temperature. The control circuit drives a number of actuators setting the temperature (90), the air flow rate (93), and the distribution of the air (91) inside the cabin. A command module (MC) defines the signals driving each of these to bring the temperature inside the cabin towards the desired temperature, as a function of a chosen law. The command module has a computer (61) that determines a magnitude linked to the existing temperature, as a function of the position of the temperature setting control. The control module sets the air distribution under a second function of the position of the temperature control.

Description

Simplified devices to aid thermal comfort on board a vehicle
The invention relates to thermal comfort aid installations on board a vehicle, more particularly the automatic control circuits which such installations comprise.

Comfort assistance is provided from a water / air exchanger for air heating from engine cooling, most often accompanied by a cold exchanger forming part of a refrigerant circuit fitted with a compressor. The temperature of the air blown into the passenger compartment is adjusted by mixing hot and cold air (the latter, refrigerated or not). An air distribution device makes it possible to distribute the air in at least three ways, towards the glazing (windshield), towards aerators (level of the users' face), and downwards (feet of the users). There is also an adjustment of the air flow, and, most of the time, manual controls for the commissioning of the refrigerant circuit, the recirculation of the air inside the passenger compartment, as well as the defrosting .

The greater the level of comfort desired, the more complex it becomes to be controlled by the user, who is often the driver. To lighten the task of the latter, and the attention which is asked of it consequently, one seeks to automate as best as possible the control circuit for assisting thermal comfort.

i
Until now, this automation has focused on temperature control, and has been carried out on the basis of different temperature sensors, for the supply air, the passenger compartment, and the exterior of the vehicle.

This leaves it up to the user to choose the air distribution. However, the Applicant has observed that this function is often poorly understood by the user, who takes decisions that are sometimes contrary to the desired comfort. It then sought to avoid this difficulty, and this in a general manner, that is to say even for relatively simple and inexpensive thermal comfort assistance installations, in which the temperature is controlled, but not regulated. .

The problem is then to have temperature information in all cases, even in the absence of the appropriate temperature sensor.

One of the aims of the present invention is to provide a solution to this problem.

A second object of the invention is to automate in priority the control of air distribution in the passenger compartment.

An additional aim of the invention is to allow the omission of any air distribution command.

The invention also aims to eliminate the outside air temperature sensor, and even the air temperature sensor in the passenger compartment.

The invention also aims, in an advanced version, to improve the phases of convergence towards the desired temperature.

The known starting point of the invention is an automatic control circuit for aiding thermal comfort on board a vehicle, of the type comprising at least one member for controlling the desired temperature, and outputs respectively connected to actuators for adjusting the air temperature, the air flow rate, and the air distribution in the passenger compartment of the vehicle, as well as a control module for defining the states of at least some of the outputs as a function of the state of the temperature control member, using at least one variable linked to the existing temperature, so as to bring the cabin temperature closer to the desired temperature, according to selected laws.

According to a general definition of the invention, the control module comprises calculation means suitable for establishing said quantity linked to the existing temperature, in the form of a predetermined function of the position of the temperature control member.

For the satisfaction of the second object of the invention, the control module has at least one working mode, in which it controls the distribution of air from another function, established taking into account said predetermined function, the position of the temperature control member.

In a simple embodiment, the temperature control member is mechanically coupled to a temperature adjustment actuator, in particular a hot air / cold air mixing flap.

According to a more advanced variant, the device has an input for a supply air temperature sensor, and the control module is arranged to regulate the supply air temperature as a function of the measurement of this supply air temperature sensor. and the position of the temperature control member.

The control module can also be arranged to automatically control a renewed air / recycled air mode actuator (recirculation) during said regulation.

The air flow can be set manually, using an air flow control member, acting on the corresponding actuator.

According to an even more advanced version, the control module has a mode in which it automatically regulates the air flow rate according to a third predetermined function of the position of the temperature control member.

Other characteristics and advantages of the invention will appear on examining the detailed description below and the attached drawings, in which - FIG. 1 illustrates a general functional diagram of an installation for assisting thermal comfort on board a vehicle; - Figure 2 illustrates a form of the control panel used in a device according to the invention; - Figure 3 is the block diagram of the actuator responsible for the distribution of air in the passenger compartment; - Figure 4 illustrates the first embodiment of the invention; - Figure 5 is a table illustrating the operating mode of the device of Figure 4; - Figure 6 illustrates a second embodiment of the invention; - Figure 7 is a table illustrating three modes of operation of the device of Figure 6; FIG. 8 is a third embodiment of the invention; - Figure 9 is a table illustrating different modes of operation of the device of Figure 8; - Figures 10A, 10B and 10C are three corresponding diagrams having on the abscissa the full scale of a desired temperature control member, and on the ordinate, respectively, the supply air temperature, the speed control rate of the blower by compared to its full scale, and the percentage of air flow among the three outlets feet, aerator, and defrosting among the three outlets towards the bottom of the passenger compartment, towards the aerators, and towards the windows (defrosting).

- Figure 11 illustrates another form of the control panel, used in the device according to Figure 8; - Figure 12 illustrates yet another form of the control panel, corresponding to a variant of the previous embodiments.

The attached drawings are, for the most part, certain. Consequently, they will not only make it possible to better understand the description, but also contribute to the definition of the invention, if necessary.

This applies in particular to the table of FIGS. 5, 7 and 9, as well as to the graphs of FIGS. 10A to 10C.

In accordance with FIG. 1, an installation for assisting thermal comfort on board a vehicle comprises an electrical supply 1. It also comprises probes 2, for example of temperature, which provide measurements illustrated functionally in 3. It also includes control panels 4, which provide user requests, illustrated functionally at 5. From a set of constraints defined in 7, as well as measurements 3 and requests 5, an actual control module 6 acts on pilots or "drivers" 8, for controlling actuators (not shown here). In the embodiment shown, the commands established by the module 6 pass through the functional block 7 illustrating the constraints.

 It is of course possible to do otherwise.

As will be better understood below, the control panel made available to the user (FIG. 2) can be reduced according to the invention to a desired temperature control 41, here illustrated in the form of a rotary button between two extreme positions, a button for controlling the air flow inside the passenger compartment, also illustrated in the form of a rotary button 43 having a zero stop position, and four increasing speeds. I1 are added switches or push buttons 44 for switching on the air conditioning system or "air conditioning", button 45 for the forced implementation of the air recirculation function, and button 46 for the forced implementation of the defrosting function.

Air distribution in the passenger compartment is usually carried out in at least three ways. I1 is known for this purpose to provide a motor 92, acting on a system of one or more mechanical shutters 920, to allow to distribute the air between the glazing (at least the windshield), aerators, which appear at less on the dashboard, and may include a manual closing control, and low gills, directed towards the feet of users, at least at the front.

The realization of the shutter system 320 can be done in different ways, considered here as known to those skilled in the art. We can use the so-called "drum" shutters, the principle of which is described in the French patent.
FR-A-1 359 909.

Three different and progressively more advanced embodiments are illustrated in FIGS. 4, 6 and 8.

These figures have common parts. They show the control circuit CC, which includes a control module MC, which includes functions 6 and 7 in FIG. 1, and in principle function 8 in FIG. 1, at least in part.

As control circuit inputs, light supply lines (0V Li, + Li) are provided, which in particular allow the lighting of the panel indicators. It is also possible to use the existence of lighting as an indication for night travel, which can lead to more intense heating.

The electronic circuits receive three supply lines: 0V El (zero electronic volts), as well as + APC (positive supply "after contact"), and + APCC (positive supply "after contact" and engine running), in known manner) .

Although it is possible to apply the invention to a vehicle not provided with air conditioning, it is here considered, as a preferential measure, that the vehicle is provided with a refrigerant circuit, the reference 99 of which illustrates the compressor. Correspondingly, there is then provided an evaporator probe illustrated at 25.

The figures concerned also show a unit for adjusting the supply air temperature, such as a mixing shutter VM, bearing the reference numeral 90.

The reference numeral 91 illustrates a unipolar distribution motor which, as already described with reference to FIG. 3, actuates the air distribution system 910. In 1992, a direct current recirculation motor (MRCC) actuates the shutter making it possible to put the passenger compartment in recirculated air mode or, on the contrary, in outside air intake, and this in all or nothing. An MVPR blower fan is also planned, bearing the reference 93.

The button for controlling the desired temperature 41 is provided with an electrical feedback system, for example using a cursor moved along a resistor 410 as a function of the rotation of the button 41, on its full scale.

Also found in Figures 4, 6 and 8 the four switches 44 to 46 already mentioned.

In FIGS. 4 and 6, the control of the blower is carried out by the switch with four active positions of FIG. 2, which directly controls the blower motor by means of a resistive ladder 930. For this purpose, the positive battery pole (+ BA) arrives through an APC "after contact" switch on the central point of switch 43.

We will see that it is different for Figure 8.

We will now describe each of the embodiments individually.

In the embodiment of FIG. 4, the button 41 is mechanically connected to the mixing shutter VM. I1 therefore directly controls the position of this flap, as a function of a desired temperature law, to which we will return later.

The electrical feedback allowed by the resistor 410 is applied to the control module MC, more precisely to a calculation means 61 placed therein. The control module
MC uses this information to prioritize the regulation of air distribution using motor 91.

This module MC also performs the management of the commands of the compressor 99 as a function of the measurements supplied by the evaporator probe 25 and of the existing temperature information (an estimate of the outside temperature), given by the calculation means 61, such as we will see it later. If necessary, it also manages the interface with the injection of the vehicle engine, to adjust this as a function of the power demanded from the engine by the refrigeration compressor, which is itself a function of the temperature. outside. Optimizing this adjustment makes it possible to better meet anti-pollution standards. For example, the teachings of French patent application No. 93 12 767, in the name of the Applicant (FR-A2 711 731), are used.

In this embodiment, the recirculation function is only manual, by actuation of button 45.

The control module MC admits at least two different operating modes. In a first mode, called "stabilized distribution" (DIS1), the air distribution or distribution rate between the windshield, the aerators and the feet, is established as a function of the mechanical position of the organ 41, as electrically defined by resistor 410.

However, another mode is provided, when the control button 41 is placed in the maximum position, and the vehicle is started. In this case, the distribution is forced in defrosting mode, as indicated by the lower boxes "DEGI" in the table of FIG. 5.

We now turn to the second embodiment of Figure 6. Compared to that of Figure 4, this embodiment of Figure 6 is increased by a supply air temperature sensor 24. In this case, the button 41 is no longer mechanically connected to the mixing flap 90. I1 is used, by its electrical feedback at 410, to control the temperature in the form of a function F, which expresses the temperature of the blown air as a function of the position of the button 41, along its full scale (first line of the table in Figure 7.

Preferably, an automatic management by the control module MC of the air recirculation actuator 92 is added to this second embodiment, in order to improve the convergences towards the desired temperature, from either a state too cold, or too hot (at least when there is air conditioning).

The rest of the device of FIG. 6 is similar to that of FIG. 4.

A third embodiment is illustrated in FIG. 8. I1 differs from the previous one essentially in that the control of the air flow is more advanced. Instead of being in five positions, as illustrated in FIG. 2, the button 43 (FIG. 11) has a special position called "automatic", as well as a stroke going continuously from a minimum value to a maximum value. air flow.

In this case, the control module MC delivers a setpoint to an interface 193, which in turn controls the speed of rotation and consequently the flow rate of the actuator 93.

If the button 43 is in its progressive manual control zone, the control module MC consequently controls the unit 193.

We will now consider the situation where the button 43 is in its automatic position. In this case, three different modes are possible - a stabilized flow mode, according to which the flow level is determined according to the required supply air temperature; - a convergence mode, in which the flow level is controlled as above, but also taking into account a gain error, that is to say the difference between the supply air temperature and its value setpoint. The fact that the blower is forced to its minimum speed of rotation is advantageously added to this condition as long as the supply air temperature remains below a threshold value at low temperatures, typically 10 C.

- a defrosting mode, where the speed of rotation of the blower is automatically forced to its maximum value.

These three modes are recalled in the table of FIG. 9, in which said modes are coupled to the corresponding modes of the dispensing actuator. With such a coupling, the current operating mode for the control module, for example the "stabilized" mode, is taken with regard to the state of three variables, which are the temperature, the flow rate and the distribution.

In all the embodiments, it is possible to force the recirculation mode by the button 45, or the defrosting by the button 46.

The recirculation mode (all or nothing) depends on the recirculation control (priority), as well as the gain error of the supply air temperature loop, and the defrost control (automatic or manual).

The control of the air conditioning compressor by the control module depends on the air conditioning control (all or nothing), the air renewal / recirculation set point, the evaporator temperature, as well as the injection of the propulsion engine (for example, the compressor being mechanically coupled to this engine, the available cooling power is zero when the vehicle engine is stopped, low when it is idling).

 I1 is now referred to in FIGS. 10A to 10C, the scales of which on the abscissa correspond.

FIG. 10A illustrates a preferred example of a temperature control law. Its abscissa scale is graduated in percentages of the full scale, from 0% to 100%.

In the drawings, this full scale is illustrated by the symbol Ce.

For the implementation of the invention, first of all, this existing scale of the desired temperature control member corresponds to an existing temperature scale, which in principle corresponds approximately to the temperature outside the vehicle. In the example illustrated, currently considered preferential, an outside temperature of -30 ° C. is taken when the desired temperature control is set to its maximum (0%), and +40 "C. when the desired temperature control is set to its minimum (100%) On the abscissa, it will be noted that the definition of the full scale percentages of the temperature control and the definition of the scale of the corresponding existing temperatures are in opposite directions to each other.

Experience has shown, on the one hand, that certain users set the desired temperature in inverse proportion to the existing temperature (at start-up, it is the outside temperature), on the other hand that it is relatively easy to encourage the all users to operate in this way, which seems natural to them.

From point A1 to point A2, that is to say for the half high (desired) temperatures of the full scale of the temperature control member, the desired temperature drops by about 100C. This corresponds to a variation of just under 40 "C for the associated existing temperature.

When the air conditioning is out of service, or if the vehicle does not have a refrigerant circuit, we continue on the same slope until point A3.

With the refrigerant circuit, the control module is arranged to decrease the temperature of the mixed air, at a rate of approximately 20 when one goes towards the desired low temperatures, from the middle zone of the full scale of the organ. temperature control (point A2), until the capacity of the refrigerant circuit is saturated (segment A4-A5).

 It is also conceivable to operate in mode at two temperature levels ("bi-level"), by stratifying the mixed air: a warmer flow goes towards the feet (A2-A3), and a cooler flow towards the tall air vents and face (A2-A4). This is illustrated, in combination, in Figures 10A and 10C.

This defines a first function f (C) which passes from the scale of the desired temperatures to the values of the set temperatures for the supply air.

Figure 10C concerns the air distribution, with the conventions indicated. Zone C1 corresponds (vertically) to the rate of air sent to the windshield (defrosting or demisting). Starting from around 80% for 0% of the Ce scale, the rate defined by the vertical extent of the C1 zone gradually decreases to around 10% for two-thirds of the Ce scale, and remains marginal for the rest.

Zone C2 corresponds to the air which is sent to the feet of users (before, in principle). The growth of the rate follows the decrease of the C1 rate, up to about two thirds of the full scale Ce, to decrease very quickly towards zero thereafter. Zone C3 corresponds to the air which is sent for ventilation. On the last third of the full scale Ce, this zone complements 100% of zones C1 and C2. In general, the air distribution favors the bottom of the passenger compartment substantially for the high temperature half of the full scale Ce, and the top of the passenger compartment, substantially for the rest of the full scale Ce.

To avoid disturbing the distribution, users can be encouraged not to close the aerators, or eliminate the possibility of closing them, leaving only the fins for orienting the air flow. This defines a second function g () of the full temperature scale Ce.

The function seems to have several results (C1 to C3); but it has only one, related to the control of a distribution system by a motor. The air distribution system is for example that described in FR-A-1 359 909, already cited. This function g () is established taking into account the definition of the function f () mentioned above.

In a variant (not shown), this other function (g) also includes a distribution of air in aeration, at least for the extreme part of said desired high temperature half of the full scale, in particular for demisting at start-up. In other words, an "aeration" segment can be provided between the zones C1 and C2 on the desired high temperature side of the full scale. This "aeration" segment can relate to a low rate (up to 10%) on the extreme side of said desired high temperature half of the full scale. Afterwards, a progressive transition zone can be provided with the zone C3. This can be used in particular for demisting at startup, and / or to warm users' hands, at very low outside temperatures.

For the embodiment of FIG. 8, and in automatic mode, the air blower is controlled according to a third function h (), which has a general shape of flattened V open upwards (FIG. 10C), with a slope stronger on the desired high temperature side than on the desired low temperature side. The flow rates are given in
Kg / hour.

These curves relate to at least one operating mode of the control module (the "stabilized" mode, with the hot and cold convergence modes, in the case of FIG. 8).

This control module will act differently in other modes, such as in the case of pure defrost, as well as in the transient starting or stopping regimes known to those skilled in the art.

The functions described above can be implemented within the control module in the form of a digital calculation element (for example microprocessor and tables in memory) or analog (amplifiers with adjusted gain curve).

We now refer to Figure 12.

The button 41 may include two full scales ceî and C02, for example symmetrical with respect to the vertical axis X1.

The one on the left corresponds to operation with air conditioning (AC), and the one on the right corresponds to operation without air conditioning (ECO). The key 44 is then deleted.

The button 44 can also have two full scales, for example symmetrical with respect to the vertical axis X2. As the symbols indicate, the one on the left corresponds to the "air renewal" mode, and the one on the right corresponds to the "air recirculation" mode. Graduation is continuous, or stepwise (as shown), with a separate automatic mode, on at least one side. Key 45 is then deleted.

When the two buttons are thus arranged, only the defrost / demister button 46 remains, in addition to the two buttons.

The order is then particularly simple and clear for the user.

Of course, the variant of FIG. 12 could be used independently of the embodiments of FIGS. 4, 6 and 8.

In the above, the supply air temperature is adjusted by a mixing flap. Of course, it could also be done in another way, in particular by acting on the flow of hot water in the water / air exchanger for air heating.

 It is also clear that the curves in FIGS. 10 illustrate an example currently considered to be preferential. They are subject to change. These modifications can take account first of all of the way in which a full scale of outside temperatures is made to correspond to the desired temperature scale. They will also take into account the material structure of the air distribution system, and the characteristics of the blower, if applicable.

The invention offers particularly interesting advantages. First, calculating an estimate of the existing (outdoor) temperature from the desired temperature control button allows you to delete the outdoor temperature sensor. Full and priority automation of the distribution makes it possible to eliminate the distribution command, at the same time as preventing the frequent misunderstanding of this command by the users leading them to operate the comfort aid under conditions that are contrary to its effectiveness. further, the embodiment of Figure 4 removes the supply air temperature sensor; that of FIG. 12 removes two of the three switches from the user panel, also improving the understanding of the user. These advantages also result in a reduction in costs, while retaining good efficiency, which is likely to facilitate the desired development of air conditioning systems on board vehicles, in particular of small displacement.

Claims (13)

Claims 1. Automatic control circuit (CC) for aiding thermal comfort on board a vehicle, of the type comprising at least one control member, for the desired temperature (41), and outputs respectively connected to actuators of regulation of air temperature (90), air flow (93), and air distribution (91) in the passenger compartment of the vehicle, as well as a control module (MC) to define the states of at least some of the outputs as a function of the input or inputs, and of the state of the temperature control member, using a quantity linked to the existing temperature, so as to approximate the temperature d cabin of the desired temperature, according to selected laws, characterized in that the control module (MC) comprises calculation means (61) suitable for establishing said quantity linked to the existing temperature, in the form of a function predetermined (f) of the position of the temperature control member. 2. Device according to claim 1, characterized in that the calculation means (61) of the control module establish said predetermined function over an interval ranging from approximately -30 C to approximately + 40 "C, for the maximum, respectively the minimum, at desired temperature, of the full scale of the temperature control member. 3. Device according to claim 2, characterized in that the control module (MC) is arranged to decrease the temperature of the mixed air, at a rate of about 10 on the high temperature half of the full scale of the temperature control. 4. Device according to claim 3, comprising a refrigerant circuit, characterized in that the control module (60) is arranged to decrease the temperature of the mixed air, at a rate of about 20 when going towards the desired low temperatures , from the middle zone of the full scale of the temperature control member, until saturation of the capacities of the refrigerant circuit. 5. Device according to one of the preceding claims, characterized in that the control module (MC) has at least one working mode, in which it controls the distribution of air from another function (g), established taking into account said predetermined function (f), the position of the temperature control member. 6. Device according to claim 5, characterized in that said other function (g) comprises an air distribution favoring the cabin bottom substantially for the desired high temperature half of the full scale of the temperature control member, and an air distribution favoring ventilation, at the top of the cabin, substantially for the rest of the full scale of the temperature control member. 7. Device according to one of claims 5 and 6, characterized in that said other function (g) also comprises a distribution of air in aeration on the extreme side of said desired high temperature half of the full scale, in particular for the demisting at startup. 8. Device according to one of the preceding claims, characterized in that the temperature control member (41) is mechanically coupled to a temperature adjustment actuator, in particular a hot air / cold air mixing flap (90) . 9. Device according to one of claims 1 to 7, characterized in that it comprises an inlet (24) for a supply air temperature sensor, and in that the control module (MC) is arranged to regulate the supply air temperature as a function of the measurement of this supply air temperature sensor and the position of the temperature control member. 10. Device according to one of the preceding claims, characterized in that it further comprises an air flow control member (43), acting on the corresponding actuator (93). 11. Device according to one of claims 1 to 9, characterized in that the control module (MC) has a mode in which it automatically regulates the air flow according to a third predetermined function (h) of the position of the temperature control device. 12. Device according to claim 11, characterized in that said third function (h) has a general shape of flattened V open upwards, with a steeper slope on the side of the desired high temperatures than on the side of the desired low temperatures. 13. Device according to one of claims 11 and 12, characterized in that the control module (MC) has a second air flow mode, in which it also takes into account the error between the temperature of supply air and its desired value.