Patent Publication Number: US-2020282796-A1

Title: Device for operating a motor vehicle air conditioning system and interior temperature sensor unit for such an air conditioning system

Description:
The invention relates to a device for operating a vehicle heating, ventilation and/or air conditioning system, as well as to an interior temperature sensor unit for such heating, ventilation and/or air conditioning system. 
     Typically, a vehicle heating, ventilation and/or air conditioning system is controlled in and by a control unit installed in the vehicle, in particular an air conditioning control unit, which is a unit separate from other control units. For the control, various sensor variables are typically required, such as e.g. relative to the interior temperature, as well as to the current operational states of various components of the air conditioning system and to the vehicle environment (e.g. outside temperature, solar irradiation etc.). 
     Examples for devices for controlling an air conditioning system and/or a plurality of vehicle components are known from DE-A-199 41 951, DE-B-10 2008 064 011 and EP-A-1 080 956. 
     With vehicles, a trend has prevailed in recent years to operate a plurality of different vehicle components through a common control unit, this common control unit also performing the calculation of the sensor variables required for the various vehicle components. The concentration of the software for controlling the various vehicle components is advantageous with regard to production costs in that the computing power required for controlling the vehicle components can be concentrated in a single or a few processors. 
     During the development phase, however, uniting a plurality of software functions for a plurality of vehicle components in a single control unit causes problems in that software updates have to be coordinated among a plurality of vehicle parts suppliers that supply the individual components to be controlled by the central control unit. This coordination may cause delays in the development of the software for e.g. the air condition control of a vehicle. 
     It is an object of the invention to provide a conception for a device for operating a vehicle heating, ventilation and/or air conditioning system, in which, despite the integration of the operation of the heating, ventilation and/or air conditioning system with the operation of other components in a central control unit, the degree of freedom in designing the software is nonetheless increased. 
     To achieve this object the invention provides a device for controlling and operating a vehicle heating, ventilation and/or air conditioning system and further vehicle components, the heating, ventilation and/or air conditioning system being provided inter alia with
         a blower,   a plurality of actuating motors for controlling flaps at and/or in channels directing air into the vehicle,   a heating and/or cooling aggregate,   a plurality of first sensors for sensing measuring variables necessary for the operation of the heating, ventilation and/or air conditioning system and   at least one second sensor as an interior temperature sensor for sensing an actual value representing the interior room temperature of the vehicle,   wherein the device is provided with
           an operating and control unit for
               the input of inter alia a set temperature for the interior of the vehicle,   the input of parameters and operating commands for the operation of the heating, ventilation and/or air conditioning system and the further vehicle components,   the output of air condition control signals for controlling the blower, the actuating motors and the heating and/or the cooling aggregate of the heating, ventilation and/or air conditioning system, and   the determination and the output of component control signals for the control of the further vehicle components,   
               
           a processing unit arranged outside of and/or separate from the operating and control unit and connected with the operating and control unit, to which processing unit measuring signals can be supplied from the at least one interior temperature sensor, as well as from at least some of the first sensors of the heating, ventilation and/or air conditioning system, the processing unit further processing these measuring signals into air conditioning control signals which can be supplied to the operating and control unit for controlling the blower, the actuating motors and/or the heating and/or the cooling aggregate or for further processing for controlling the blower, the actuating motors and/or the heating and/or the cooling aggregate of the heating, ventilation and/or air conditioning system.       

     Further, the above object is achieved according to the invention with an interior temperature sensor unit for a vehicle heating, ventilation and/or air conditioning system comprising an actuator system, wherein the interior temperature sensor unit is provided with
         at least one and preferably a plurality of interior temperature sensors for determining a variable representing the interior temperature of the vehicle and   a processing unit to which measuring signals can be supplied from the interior temperature sensor or sensors, as well as data representing measuring signals from other sensors of the heating, ventilation and/or air conditioning system, and which processing unit provides signals for the actuator system of the heating, ventilation and/or air conditioning system for transmission to an external control unit for controlling this actuator system of the heating, ventilation and/or air conditioning system.       

     Basically, the invention consists in the splitting of the functions of the heating, ventilation and/or air conditioning regulation or control between an operating and control unit for a plurality of vehicle components, inter alia also for the heating, ventilation and/or air conditioning system, and a processing unit arranged externally thereof. This processing unit is advantageously associated to the interior temperature sensor and is in particular comprised in one structural unit with the same. The processing unit receives signals from other sensors of the heating, ventilation and/or air conditioning system, whose measuring variables are necessary for regulation/control. 
     Thus, according to the invention, at least a part of the air condition regulation functions is transferred from the central operating and control unit associated to a plurality of vehicle components to the interior temperature sensor, i.e. a processing unit associated to the same. Together, these functions form in particular the core functions of air conditioning such as the evaluation of (in particular the entire) sensor system and the calculation of the necessary quantity of air, air temperature, as well as the heating or cooling requirement necessary therefor. 
     The essential part of the core functions of air conditioning also includes, inter alia, the calculation of the actuation variable for the actuator system of the heating, ventilation and/or air conditioning system, such as e.g. the actuation variables for the actuating motors of the flaps at and/or in channels directing air into the vehicle, for the blower and for the heating and/or the cooling aggregate. These are eventually calculated from the requirements made with respect to air quantities, air temperatures, air distribution, heating powers and cooling powers. Thereby, not only the interior temperature is processed in the decentralized processing unit, but also a considerable number of further air condition regulation functions is performed. In order to calculate these functions, the required information is made available to the processing unit e.g. via a bus communication. The calculation results are transmitted via the bus communication to further control units and in particular to the operating and control unit which can use these to operate the various actuator systems of the heating, ventilation and/or air conditioning system. 
     The advantage of splitting the air conditioning functions, as provided by the invention, between the control of the air conditioning system by the central operating and control unit and the calculation of the actuation variables for the control of the air conditioning system by a processing unit which is decentralized with respect to the operating and control unit, consists in the flexibility in the software development for the heating, ventilation and/or air conditioning system. Prior thereto, the interfaces between the processing unit or the interior temperature sensor on the one hand and the central operating and control unit have to be defined. Here, the connection is feasibly made via a standard bus communication, e.g. CAN. Software changes for determining the signals and data for controlling the air conditioning system, which are to be transmitted via this bus communication interface, now require no change in the software for operating the central operating and control unit, which means additional flexibility as far as the software designer is concerned. 
     In an advantageous embodiment of the invention it may be provided that the first sensors are connected to the operating and control unit and supply their measuring signals to the same, wherein the operating and control unit supplies data representing these measuring signals to the processing unit. In this variant of the invention the various sensors for the operation of the are conditioning system are connected to the central operating and control unit. This does not apply to the at least one interior temperature sensor. The further sensors (first sensors) are of various types and hardware and in part provide analog measuring signals, but in part also provide digitalized measuring signals. They may be used for different functions. For example the outside temperature sensor, which is typically required for the operation of an air conditioning system, may also be used to indicate to a driver in winter that temperature has fallen below a minimum. But also in very general terms it is common today that the outside temperature is displayed on the dashboard of a vehicle. The measuring signals of these first sensors are advantageously converted in the operating and control unit to be subsequently transmitted to the external processing unit via e.g. a bus (CAN or LIN bus). Together with the measuring signal from the at least one interior temperature sensor, the actuation variables required for the operation of the air conditioning system are then determined in the processing unit, and these data are transmitted from the processing unit via the bus communication link to the operating and control unit from where they are supplied to the individual components of the air conditioning system to control the same accordingly. 
     Regarding the type of the interior temperature sensor, the same may be vented or not vented. Besides a temperature-sensitive element, a vented internal temperature sensor further requires a ventilation motor. Recently, so-called non-vented interior temperature sensors are increasingly used which comprise a plurality of elements that differ in sensitivity and are sensitive to different ambient parameters. Such non-vented temperature sensors typically comprise two temperature-sensitive measuring elements, as well as a radiation-sensitive element that senses the heating of the non-vented interior temperature sensor caused by heat or solar radiation. The measuring signals of these three elements in common calculated to generate a signal representing the temperature in the interior of the vehicle, which signal is supplied as the actual value of the interior temperature to the regulator (controller) of the air conditioning system. 
     In a further suitable embodiment of the invention the first sensors may comprise: at least one sensor for sensing the temperature of the air flowing from at least one of the channels and/or at least one sun sensor for sensing the solar irradiation the vehicle interior is exposed to and/or at least one humidity sensor for sensing the relative air humidity of the air reaching in particular a window, in particular the windshield of the vehicle, and/or at least one outside temperature for sensing the temperature of a heating aggregate of the air conditioning system and/or a sensor for sensing the temperature of a cooling aggregate of the air conditioning system. 
    
    
     
       The invention will be explained hereunder in more detail with reference to an embodiment and with reference to the drawings. In the Figures: 
         FIG. 1  schematically illustrates a part of a vehicle with some components of an air conditioning system, and 
         FIG. 2  schematically shows the splitting of the air conditioning functions between a central operating and control unit and a decentral processing unit. 
     
    
    
       FIG. 1  is a side view and schematic illustration of the front part of a vehicle  10  comprising an air conditioning system  12 . The air conditioning system  12  comprises, inter alia, a blower  14 , a heating aggregate  16 , a cooling aggregate  18 , a plurality of air supply channels  20  with actuating motors  26  for flaps  24 , and a sensor system comprising e.g. an interior temperature sensor  26 , a sun sensor  28  and an outside temperature sensor  30 . The interior temperature sensor  26  may comprise one or a plurality of temperature sensors which in their entirety serve to determine an actual variable representing the temperature in the interior. 
     A central operating and control unit  32  is installed in the dashboard or in the centre console of the vehicle  10 , the unit comprising e.g. a touchscreen  34 . The operating and control unit  32  serves to control the actuator system of the air conditioning system  12  and e.g. a navigation system  36 , and further serves to adjust and/or temperature-control (heat or vent) the seats (see  38  in  FIG. 2 ). Further components such as e.g. an infotainment system or a sunroof device or an automatic roof opening and closing system (in case of a convertible) may also be controlled via the central operating and control unit  32 . 
     According to the invention a part of the air condition control functions has been transferred from the operating and control unit  32  to external means. In the present exemplary case a decentral processing unit  40 , which is integrated with e.g. the interior temperature sensor  26 , is located in a separate structural unit  42  which communicates with the central operating and control unit  32  via a bus communication  44 . Here, the measuring data of other air condition sensors, such as e.g. the sun sensor  28  or the outside temperature sensor  30  or the motor water temperature sensor, the air ejection sensor, the humidity sensor, the heating aggregate sensor, i.e. the heat exchanger temperature sensor, the cooling aggregate sensor, i.e. the evaporator temperature sensor (not illustrated in detail, but indicated by the dots between  28  and  30  in  FIG. 2 ), can be supplied to the processing unit  40  preferably also via bus communication. The above sensors and possibly other sensors (except for the interior temperature sensor  20 ) supply their measuring signals or measuring data to the central operating and control unit  32  in which these signals are converted for transmission to the processing unit  40  via the bus communication line  44 . Together with the measuring signal of the interior temperature sensor  26 , the processing unit  40  then calculates the actuation variables for the individual components of the air conditioning system  12 , such as e.g. the blower  14 , the heating aggregate  15 , the cooling aggregate  18  and the various air distribution flaps  24  and also a central mixing flap. These actuation variables are transmitted back to the central operating and control unit  32  via the bus communication line  44 , from where they are transmitted to the corresponding components of the air conditioning system  12 . 
     LIST OF REFERENCE NUMERALS 
     
         
           10  vehicle 
           12  air conditioning system 
           14  blower 
           16  heating aggregate 
           18  cooling aggregate 
           20  air supply channels 
           22  actuating motors 
           24  flaps 
           26  interior temperature sensor 
           28  sun sensor 
           30  outside temperature sensor 
           32  control unit 
           34  screen 
           36  navigation system 
           40  processing unit 
           42  structural unit 
           44  bus communication