DESC:FILED OF THE INVENTION
[0001] The present invention relates to the field of Heating, Ventilation, and Air-Conditioning (HVAC) systems. In particular, the present invention relates to a system and method for switching functioning of actuators for HVAC systems.

BACKGROUND
[0002] The information in this section merely provides background information related to the present invention and may not constitute prior art(s) for the present invention.
[0003] Heating, Ventilation and Air Conditioning (HVAC) systems are used in a closed environment such as in a vehicle to maintain good indoor air quality (IAQ) by controlling multiple parameter values, such as the temperature and humidity of the air inside the vehicle and also to purify and circulate air throughout the vehicle.
[0004] A typical HVAC system incorporates several technologies to maintain adequate ventilation, filtration, and to provide thermal comfort. For example, the HVAC systems include various types of sensors, such as temperature sensors, humidity sensors, air quality sensors, etc. The sensors may be installed inside and outside of the vehicles, and the HVAC system may receive an input from said sensors for continuously capturing real-time parameter values, which enables the HVAC system to instantly compare the real-time captured parameter values with a pre-set desired parameter value. The HVAC systems further include one or more actuators, and as the air in the HVAC system flows through ducts or pipes, the one or more actuators enable the opening or closing of certain portions of the duct or pipes to control the temperature inside the vehicle or to control a direction of the airflow inside the vehicle. The HVAC system controls the position of the one or more actuators to regulate the temperature inside the vehicle or to control the direction of the airflow.
[0005] A conventional HVAC system uses a feedback-based mechanism to control the position of the one or more actuators. The HVAC system may receive feedback from the actuators, in the form of a signal, to determine the exact position of one or more actuators. This information facilitates the HVAC System to control and monitor its operation. For example, the conventional HVAC system may detect whether the one or more actuators have reached a desired position based on the feedback signal received from the one or more actuators, and based on the detection, the HVAC system may stop the one or more actuators once the one or more actuators reach the desired position.
[0006] However, the conventional HVAC systems are susceptible to failure due to malfunctioning of the feedback-based mechanism. In one exemplary situation, the feedback-based mechanism may fail when the one or more actuators fail to provide a feedback signal to the HVAC system. In this situation, in the absence of the feedback signal, the conventional HVAC system may continue to expect a feedback signal and may reattempt to receive the feedback signal from the one or more actuators. However, even after multiple reattempts, if the feedback signal is not received, the actuator may not stop at the desired position, and after a certain time duration may lead to the failure of the HVAC system. In another exemplary situation, the feedback-based mechanism may fail when the one or more actuators provide wrong feedback to the HVAC system. In this situation, upon receiving the wrong feedback from the HVAC system, the actuator may fail to stop at the desired position, which may lead to the failure of the HVAC system after a certain time duration. Therefore, the conventional systems may fail on malfunctioning of the feedback-based mechanism of the one or more actuators, thereby degrading the user experience.
[0007] Hence, there is a need to provide a system and a method that can overcome the above-discussed problems of the conventional HVAC systems.
[0008] The drawbacks and limitations of the conventional techniques explained in the background section are just for exemplary purposes and the invention would never limit its scope only such limitations. A person skilled in the art would understand that this invention and below mentioned description may also solve other problems or overcome the other drawbacks/disadvantages of the conventional arts which are not explicitly captured above.

SUMMARY
[0009] This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended for determining the scope of the invention.
[0010] The present invention relates to a system for switching functioning of actuators for an HVAC system.
[0011] According to another aspect of the present invention, a Heating Ventilation and Air Conditioning (HVAC) system for switching functioning of actuators using a time-based logic is disclosed. The HVAC system includes an actuator feedback module, a determination module, an actuator module, and a switch scanning module. The actuator feedback module is configured to receive feedback from the actuators at regular intervals for a first predetermined time duration. The determination module is in communication with the actuator feedback module. The determination module is configured to compare a value associated with the feedback with a threshold value. The actuator module is in communication with the determination module. The actuator module is configured to transmit one of the plurality of control signals to the actuators based on the comparison results. The switch scanning module is in communication with the determination module. The switch scanning module is configured to determine a current position of a plurality of switches. The actuator module in communication with the determination module is configured to switch the actuators between a feedback-based logic to time-based logic by producing a plurality of control signals for the actuator based on the determined direction and time duration of movement of the actuators as well as the current position of at least one of the plurality of switches in case of detected absence or incorrectness of feedback signals.
[0012] According to an aspect of the present invention, a method for switching functioning of actuators using a time-based logic is disclosed. The method includes receiving, by an actuator feedback module, feedback from the actuators at regular intervals for a first predetermined time duration. The method further includes evaluating, by a determination module, whether a value associated with the feedback in real-time is equal to or greater than a threshold value. The method further includes transmitting one of the plurality of control signals based on the evaluation, by an actuator module, to the actuators. The control signals include a first signal to continue the feedback mechanism and to stop the actuator once the actuator has reached the desired position, in case of the value associated with the feedback is less than the threshold value. The control signals further include a second signal to stop the actuators and switch from the feedback-based logic to a time-based logic, in case of the value associated with the feedback is equal to or greater than the threshold value.
[0013] The method further includes determining, by a switch scanning module, a current position of at least one of the plurality of switches for the time-based logic, in case of the value associated with the feedback is equal to or greater than the threshold value. The method further includes determining, by the determination module, a direction and a time duration for a movement of the actuators based on the determined current position of the at least one of the plurality of switches. Further, the method includes determining, by the determination module a time out duration for the movement of the actuators and allowing movement of actuators for a second predetermined time duration. Further, the method includes transmitting, by the actuator module to the actuators, a third signal to resume the movement of the actuators in the determined direction for the second predetermined time duration. Further, the method includes transmitting, by the actuator module to the actuators, a fourth signal to stop the movement of the actuators upon completion of the second predetermined time duration. Furthermore, the method may include transmitting, by the actuator module to the actuators, a fifth signal to restart the movement of the actuators and resume the functionality based on the feedback logic.
[0014] To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0016] FIG. 1 illustrates a schematic block diagram depicting an environment for Heating Ventilation and Air Conditioning (HVAC) system for switching functioning of one or more actuators using a time-based logic, in accordance with an embodiment of the present invention;
[0017] FIG. 2 illustrates a schematic block diagram depicting an exemplary HVAC system incorporated in the HVAC controlling device for switching functioning of the one or more actuators using a time-based logic, in accordance with an embodiment of the present invention;
[0018] FIG. 3 illustrates a functional block diagram of an HVAC system for switching functioning of the one or more actuators using a time-based logic, according to an embodiment of the present invention;
[0019] FIG. 4 illustrates a feedback type circuit diagram for the HVAC control unit, according to an embodiment of the present invention;
[0020] FIG. 5 illustrates a flowchart depicting an exemplary method for switching functioning of one or more actuators for the HVAC system, according to an embodiment of the present invention; and
[0021] FIG. 6 illustrates a flow chart of a method for switching functioning of the one or more actuators for the HVAC system 200, according to an embodiment of the present invention.
[0022] Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

DETAILED DESCRIPTION
[0023] For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the various embodiments and specific language will be used to describe the same. It should be understood at the outset that although illustrative implementations of the embodiments of the present disclosure are illustrated below, the present invention may be implemented using any number of techniques, whether currently known or in existence. The present disclosure is not necessarily limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary design and implementation illustrated and described herein, but may be modified within the scope of the present disclosure.
[0024] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the invention and are not intended to be restrictive thereof.
[0025] Reference throughout this specification to “an aspect”, “another aspect” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase “in an embodiment”, “in another embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
[0026] It is to be understood that as used herein, terms such as, “includes,” “comprises,” “has,” etc. are intended to mean that the one or more features or elements listed are within the element being defined, but the element is not necessarily limited to the listed features and elements, and that additional features and elements may be within the meaning of the element being defined. In contrast, terms such as, “consisting of” are intended to exclude features and elements that have not been listed.
[0027] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term “or” as used herein, refers to a non-exclusive or unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0028] As is traditional in the field, embodiments may be described and illustrated in terms of blocks that carry out a described function or functions. These blocks, which may be referred to herein as units or modules or the like, are physically implemented by analog or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits, or the like, and may optionally be driven by firmware and software. The circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like. The circuits constituting a block may be implemented by dedicated hardware, by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block. Each block of the embodiments may be physically separated into two or more interacting and discrete blocks without departing from the scope of the invention. Likewise, the blocks of the embodiments may be physically combined into more complex blocks without departing from the scope of the invention.
[0029] The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents, and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.
[0030] The present invention delineates an improved Heating Ventilation and Air Conditioning (HVAC) system for switching functioning of one or more actuators. Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[0031] FIG. 1 illustrates a schematic block diagram depicting an environment 100 for Heating Ventilation and Air Conditioning (HVAC) system for switching functioning of one or more actuators 108 using a time-based logic, in accordance with an embodiment of the present invention. The environment 100 includes the HVAC control unit 102, a user input control 104, an intake/evaporator sensor 106, and one or more actuators 108. The HVAC control unit 102 may be configured to receive a feedback signal 110 from the one or more actuators 108.
[0032] In an embodiment, the HVAC control unit 102 is configured to receive a signal from the user input control 104 (preferably referred to as input control 104). The signal from input control 104 may correspond to a signal from at least one of the switches on a control panel of the HVAC system. Alternatively, the HVAC control unit 102 may also be configured to receive the signal from the input control 104 from a handheld remote-control device (not shown in the figure) via infrared or Bluetooth connectivity, or a like. The input control 104 may regulate the temperature and an airflow setting of the HVAC system.
[0033] The HVAC control unit 102 may also be in connection with a plurality of sensors that continuously capture real-time parameter values from the interior and exterior surroundings of a cabin of a vehicle. In an embodiment, the HVAC control unit 102 may be adapted to receive a signal from the intake/evaporate sensor 106. The environment 100 may further include numerous other sensors essential for the functioning and operation of the HVAC system, however, for the purpose of explanation only intake/evaporate sensor 106 is illustrated in the figure. The intake/evaporate sensor 106 may be responsible for measuring the evaporator core temperature. Since the operating temperature of the evaporator is closer to about 0°C, the intake/evaporate sensor 106 may provide real-time parameter values to the HVAC control unit 102 to take appropriate measures to prevent the core from freezing.
[0034] In an embodiment, the HVAC control unit 102 may provide a signal to control the movement of the one or more actuators 108. In an exemplary non-limiting embodiment, the one or more actuators 108 may include an AC motor actuator responsible for the actuation of the AC motor operation. In another exemplary non-limiting embodiment, the one or more actuators 108 may include a defogging motor actuator, responsible for the actuation of the defogging motor operation. In an embodiment, the one or more actuator 108 may be configured to send feedback 110 at regular intervals. The feedback 110 from the one or more actuators 108 may help to determine the exact position of the actuator to the HVAC control unit 102.
[0035] In an embodiment, the HVAC control unit 102 of the present invention is configured to monitor if any change in the feedback 110 is detected. In case any change in feedback 110 or any abnormal feedback is detected, the HVAC control unit 102 may provide a signal to the one or more actuators 108 to switch the functioning from the feedback-based logic to a time-based logic. The time-based logic functioning may allow the one or more actuators 108 to move for a predetermined time duration in a direction as may be indicated in the received signal to achieve the intended feedback. Accordingly, the one or more actuators 108 may stop on completion of the predetermined time duration. The direction of the movement provided to the one or more actuators 108 may be in accordance with the signal received from input control 104 on operating at least one switch on the control panel of the HVAC system. In an embodiment, the HVAC control unit 102 of the present invention is configured to stop the one or more actuators 108 in an event of absence or incorrectness of the feedback 110. Therefore, the present invention may avoid costly damage, which otherwise may be caused in case of the absence of feedback or incorrect feedback received by the HVAC control unit 102. In an example scenario, dampers may be controlled by the one or more actuators 108 to allow outside air to enter for a brief moment to prevent coils from freezing. However, in case of wrong feedback 110 or absence of feedback 110 from the one or more actuators 108, the correct position of the dampers may not be known. This may lead to improper controlling of the one or more actuators 110, resulting in improper controlling of the dampers, which may result in the freezing of the evaporator core. Such an example scenario may cause serious damage to the evaporator core and diminish the overall HVAC operation.
[0036] In an embodiment, the one or more actuators 108 may be used for controlling the air distribution flap. In an embodiment, the position of the air distribution mode flap may be detected based on a position feedback voltage from the one or more actuators 108. The one or more actuators 108 shall be moved either in a clockwise or counter-clockwise direction to achieve the intended position feedback voltage in accordance with a selected mode. In an embodiment, the position feedback voltage from the one or more actuators 108 may be continuously monitored, and if any change in feedback voltage is detected, the one or more actuators 108 may be moved accordingly to achieve the intended feedback.
[0037] The HVAC system of the present invention overcomes the limitation of the conventional techniques, as mentioned in the above mentioned scenario, by providing a switching functioning of the one or more actuators 108 using a time-based logic, wherein the one or more actuators 108 may turn off after the completion of the predetermined time duration. Therefore, the present invention ensures unobstructed functioning of the operations of the HVAC system even on detection of a failure of the feedback-based mechanism or absence of signal from the feedback-based mechanism of the one or more actuator 108 in the HVAC system.
[0038] FIG. 2 illustrates a schematic block diagram depicting an exemplary HVAC system 200 for switching functioning of the one or more actuators 108 using a time-based logic, in accordance with an embodiment of the present invention.
[0039] The system 200 may include the HVAC control unit 102, wherein the HVAC control unit 102 may include, but is not limited to, one or more processors 202, a memory 204, an Input/Output (I/O) interface 206, one or more modules 208, and data 210. The one or more modules 208 and the memory 204 may be coupled to the one or more processors 202.
[0040] As a non-limiting example, the one or more processors 202 can be a single processing unit or several units, all of which could include multiple computing units. The one or more processors 202 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the one or more processors 202 are adapted to fetch and execute computer-readable instructions and data stored in the memory 204. Among other capabilities, the one or more processors 202 may be configured to fetch and execute computer-readable instructions and data stored in the memory 204. The one or more processors 202 may be disposed in communication with one or more input/output (I/O) devices via the IO interface 206. The I/O interface 206 employ general wireless and/or wired communication techniques.
[0041] The memory 204 is configured to store instructions executable by the one or more processors 202. In one embodiment, the memory 204 communicates via a bus within the system 200. The memory 204 includes, but is not limited to, a non-transitory computer-readable storage media, such as various types of volatile and non-volatile storage media including, but not limited to, random access memory, read-only memory, programmable read-only memory, electrically programmable read-only memory, electrically erasable read-only memory, flash memory, magnetic tape or disk, optical media and the like. In one example, the memory includes a cache or random-access memory (RAM) for the one or more processors 202. In alternative examples, the memory 204 is separate from the one or more processors 202 such as a cache memory of a processor, the system memory, or other memory. The memory 204 is an external storage device or a database for storing data. The memory 204 is operable to store instructions executable by the one or more processors 202. The functions, acts, or tasks illustrated in the figures or described are performed by the programmed processor for executing the instructions stored in the memory 204. The functions, acts, or tasks are independent of the particular type of instruction set, storage media, processor, or processing strategy and may be performed by software, hardware, integrated circuits, firmware, micro-code, and the like, operating alone or in combination. Likewise, processing strategies include multiprocessing, multitasking, parallel processing, and the like.
[0042] The one or more modules 208, amongst other things, include routines, programs, objects, components, data structures, etc., which perform particular tasks or implement data types. The modules 208 may also be implemented as, signal processor(s), state machine(s), logic circuitries, and/or any other device or component that manipulates signals based on operational instructions.
[0043] Further, the one or more modules 208 can be implemented in hardware, instructions executed by a processing unit, or by a combination thereof. The processing unit can comprise a computer, a processor, such as the one or more processor 202, a state machine, a logic array, or any other suitable devices capable of processing instructions. The processing unit can be a general-purpose processor which executes instructions to cause the general-purpose processor to perform the required tasks or, the processing unit can be dedicated to performing the required functions. In another embodiment of the present invention, the one or more modules 208 may be machine-readable instructions (software) which, when executed by a processor/processing unit 202, perform any of the described functionalities.
[0044] In an embodiment, the one or more modules 208 may include an actuator feedback module 212, a determination module 214, an actuator module 216, and a switch scanning module 218. The actuator feedback module 212, the determination module 214, the actuator module 216, and the switch scanning module 218 may be in communication with each other. The data 210 serves, amongst other things, as a repository for storing data processed, received, and generated by one or more of the one or more modules 208. In an embodiment, the plurality of modules 208 may be configured to perform various operations or steps that may be discussed and explained in detail in conjunction with FIG. 5 and FIG. 6.
[0045] In an embodiment, the actuator feedback module 212 may be configured to receive feedback 110 from the one or more actuators 108 at regular intervals for a first predetermined time duration. In an embodiment, the actuator feedback module 212 includes a plurality of logic circuits in communication with a feedback circuit containing sensors or similar devices capable of taking/receiving information on current position of the actuators. The plurality of logic circuits includes a set of instructions configured therein. In a non-limiting example, the first predetermined time duration may be of two seconds. In another non-limiting example, the first predetermined time duration may be of four seconds. In yet another non-limiting example, the first predetermined time duration may be of any user defined time duration.
[0046] In an embodiment, the determination module 214 may be in communication with the actuator feedback module 212. In particular, the determination module 214 may be a plurality of logic circuits configured with a set of instructions, in communication with the actuator feedback module 212. The determination module 214 may be configured to compare a value associated with the feedback 110 with a threshold value.
[0047] In an embodiment, the switch scanning module 218 may be in communication with the determination module 214. In particular, the switch scanning module 218 includes a plurality of logic circuits in communication with the determination module 214 and a plurality of switches. The plurality of logic circuits are configured with an application configured to determine the current position of the plurality of switches by receiving and analysing signals from them. In an embodiment, the plurality of switches associated with the HVAC system 200 may include a temperature knob, a rotary switch, and mode control switches. In an embodiment, the actuator feedback module 212 receives feedback 110 from the one or more actuators 108, upon the plurality of switches are operated by a user. In an embodiment, the switch scanning module 218 may be configured to scan the plurality of switches at regular intervals. In particular, the switch scanning module 218 may be configured to scan the plurality of switches every 10 msec. In an embodiment, the determination module 214 may be configured to determine, based on a result of the scanning, whether the plurality of switches are operated by the user.
[0048] In an embodiment, the actuator module 216 may be in communication with the determination module 214. In particular, the actuator module 216 includes a plurality of logic circuits configured with an application in communication with the determination module 214 and is configured to produce a plurality of control signals. The actuator module 216 may be configured to transmit one of the plurality of control signals to the one or more actuators 108 based on the comparison results. In an embodiment, the actuator module 216 is configured to switch the one or more actuators 108 between a feedback-based logic to time-based logic by producing a plurality of control signals for the one or more actuators 108 based on the determined direction and time duration of movement of the one or more actuators 108 as well as the current position of at least one of the plurality of switches in case of detected absence or incorrectness of feedback signals 110.
[0049] In an embodiment, the plurality of control signals produced by the actuator module 216 may include a first signal that may allow the feedback mechanism to continue and may stop the one or more actuators 108 once the one or more actuators 108 have reached a desired position, in case of the value associated with the feedback 110 is less than the threshold value of the feedback 110. The desired position may correspond to a pre-determined destination position of the one or more actuators 108 to move into in correspondence to information received from the plurality of control signals. In an embodiment, the plurality of control signals produced by the actuator module 216 may include a second signal that may stop the one or more actuators 108 and may switch the functioning of one or more actuators 108 from the feedback-based logic to a time-based logic, in case of the value associated with the feedback 110 is equal to or more than the threshold value. In an embodiment, the plurality of control signals produced by the actuator module 216 may include a third signal that may resume the movement of the one or more actuators 108 in a determined direction for a second predetermined time duration. In an embodiment, the second predetermined time duration is greater than the first predetermined time duration. In a non-limiting example, the second predetermined duration may be of four seconds. In another non-limiting example, the second predetermined duration may be of six seconds. In yet another non-limiting example, the second predetermined time duration may be of any user defined time duration. In an embodiment, the plurality of control signals produced by the actuator module 216 may include a fourth signal that may stop the movement of the one or more actuators 108 upon completion of the second determined time duration. In an embodiment, the plurality of control signals produced by the actuator module 216 may include a fifth signal that may restart the movement of the one or more actuators 108 based on the received feedback 110. In a further embodiment, on the determination that the user has operated the one of the plurality of switches, the actuator module 216 may turn the actuators 108 ON or OFF as per the pressed switch.
[0050] FIG. 3 illustrates a functional block diagram 300 of an HVAC system 200 for switching functioning of the one or more actuators 108 using a time-based logic, according to an embodiment of the present invention.
[0051] The HVAC system 200 or HVAC control system 200 may include the HVAC control unit 102 (preferably referred to as control unit 102) comprising a microcontroller 102a. The system 200 may further include an electronics compressor variable displacement (ECVD)/AC driver 302, a connector 304, a power supply 306, a servo H-bridge driver 308, an evaporator sensor 106, LED switches 310, and an HVAC control panel comprising a rotary switch 312, a rotary switch potentiometer (POT) 314 (preferably referred to as temperature knob 314), and mode control switches 316.
[0052] In an embodiment, the microcontroller 102a is an Electronic Temperature Controller (ETC). In an embodiment, the microcontroller 102a may, using one or more modules 208, be configured to interact with and control all peripherals of electronics, hardware components, and temperature controls of the system 200.
[0053] In an embodiment, the ECVD/AC driver 302 may be a high side driver configured to turn ON and turn OFF an AC blower. In an embodiment, the power supply 306 may provide 5 Vdc VCC to the microcontroller 102a for powering the system 200. The input voltage range of electronic components and temperature control input voltage may range from 8 Vdc to 16 Vdc. The HVAC control panel may further include, Hexa Half Bridge Driver, and voltage regulator.
[0054] In the operation of the HVAC system 200 for switching functioning of one or more actuators 108 using a time-based logic, the actuator feedback module 212 may receive feedback 110 from the one or more actuators 108 at regular intervals for the first predetermined time duration. The feedback 110 may further indicate the current position of the actuator 108. In an embodiment, the actuator feedback module 212 may further receive feedback 110 from one or more feedback devices, including sensors to determine the position and working of the one or more actuators 108. The feedback received by the actuator feedback module 212 from the one or more actuators 108 may enable the determination module 214 of the microcontroller 102a to monitor and determine the exact position of the one or more actuators 108, which is essential for the accurate and precise operation of the HVAC system 200.
[0055] In an embodiment, the evaporator 106 may be configured to absorb heat, remove humidity from the air, and distribute cooling effects to the inside of the cabin via an AC blower fan. The evaporator 106 may include an evaporator sensor. The evaporator sensor may be in direct connection with the microcontroller 102a, facilitating in receiving of the temperature feedback by the actuator feedback module 212. The evaporator sensor may be configured to measure the temperature in duct forefront air streams. In an embodiment, the evaporator sensor may be a resistor whose value may change with the change in the temperature. Accordingly, the feedback 110 received by the actuator feedback module 212 may be transmitted to the determination module 214 in communication with the actuator feedback module 212.
[0056] The determination module 214 may analyse the value associated with the feedback by comparing the value with the threshold value. In particular, the determination module 214 may evaluate whether the value associated with the feedback 110 in real-time is equal to or greater than the threshold value. In particular, analysis of the feedback 110 allows the determination module to determine if the actuator 108 has reached the desired position. Accordingly, the determination module 214 may provide its analysis to the actuator module 216.
[0057] The actuator module 216 may transmit one of a plurality of control signals to the one or more actuators 108, to control the one or more actuators 108, based on the comparison results or analysis of the determination module 214. In an embodiment, the actuator module 216, upon receiving an input from the determination module 214, may transmit one of the plurality of control signals to the one or more actuators 108 for activating one of the one or more actuators 108 to control the temperature flap position for cabin cooling/heating. In another embodiment, the actuator module 216, upon receiving an input from the determination module 214, may transmit one of the plurality of control signals to the one or more actuators 108 for activating one of the one or more actuators 108 to control the air intake flap/damper, thereby allowing at least one of, fresh atmospheric air to enter the cabin and/or recirculation of cabin air for cabin cooling.
[0058] In one scenario, if the determination module 214, based on the evaluation, determines that the feedback 110 received by the actuator feedback module 212 is less than the threshold value, the actuator module 216 may transmit the first signal to continue the feedback mechanism and to stop the actuator 108 once the actuator 108 has reached the desired position.
[0059] In another scenario, if the determination module 214, based on the evaluation, determines that the feedback 110 received by the actuator feedback module 212 is equal to or greater than the threshold value, the actuator module 216 may transmit the second signal to stop the one or more actuators 108 and switch from a feedback-based logic to a time-based logic.
[0060] In an embodiment, the actuator module 216 may transmit one of the plurality of control signals to the one or more actuators 108 via servo H-bridge driver 308. In particular, the servo H-bridge driver 308 may be configured to drive the one or more actuators 108 on receiving one of the plurality of control signals from the actuator module 216. Further, the servo H-bridge driver 308 may be configured to turn ON/OFF the actuator motor in response to the plurality of control signals received from the actuator module 216. The actuator motor may rotate the flap of the AC blower as per the received control signals from the actuator module 216. In an embodiment, there may be two or more actuators 108 depending upon the number of zones in which the temperature and the air flow control may be required. In a preferable embodiment, there may be four or more actuators 108, depending upon the number of zones in which the temperature and the air flow control may be required.
[0061] In one example, the actuator feedback module 212 may receive an AC motor actuator feedback 110a from the AC motor actuator after every predetermined interval. In an embodiment, the AC motor actuator feedback 110a may be used for sensing a position of the AC motor actuator via ADC value. Further, the determination module 214 may evaluate that the feedback 110a received by the actuator feedback module 212 is either absent or incorrect. Accordingly, the actuator module 216 may transmit the second control signal to one of the one or more actuators 108, for example, an AC motor actuator, responsible for the actuation of the AC motor operation, based on the analysis of the determination module 214. Accordingly, the actuator module 216 may switch the AC motor actuator from the feedback-based logic to the time-based logic by producing a plurality of control signals for the AC motor actuator. These plurality of control signals are generated based on the determined direction and time duration of movement of the AC motor actuator as well as the current position of at least one of the plurality of switches of the control panel in case of detected absence or incorrectness of feedback signals 110.
[0062] In another example, the actuator feedback module 212 may receive a defogging motor actuator feedback 110b from the defogging motor actuator after every predetermined interval. In an embodiment, the defogging motor actuator feedback 110b may be used for sensing a position of the defogging motor actuator via ADC value. Further, the determination module 214 may evaluate that the feedback 110b received by the actuator feedback module 212 is either absent or incorrect. Accordingly, the actuator module 216 may transmit the second control signal to one of the one or more actuators 108, for example, a defogging motor actuator, responsible for the actuation of the defogging motor operation, based on the analysis of the determination module 214. Accordingly, the actuator module 216 may switch the defogging motor actuator from the feedback-based logic to the time-based logic by producing a plurality of control signals for the defogging motor actuator. These plurality of control signals are generated based on the determined direction and time duration of movement of the defogging motor actuator as well as the current position of at least one of the plurality of switches of the control panel.
[0063] In an embodiment, the switch scanning module 218, including the set of instructions and logic circuits, may determine the current position of the plurality of switches. In an embodiment, the switch scanning module 218 may receive an input signal from an HVAC control panel comprising one or more switches. The HVAC control panel may include mode control switches 316 the rotary switch 312 and the temperature knob 314 to control the temperature and airflow setting for the HVAC system 200.
[0064] Further, the switches of the control panel may implement an input position-based mechanism, where output values of an analog-to-digital converter (ADC) coupled to the switch may be taken as input by the switch scanning module 218. In an embodiment, the temperature knob 314 may send ADC value to the switch scanning module 218 for increasing and decreasing the temperature values to detect max cool and max hot positions on the temperature knob 314. In an exemplary embodiment, every position from a center position to an extreme position in a counter-clockwise direction may correspond to “cool” function, with the extreme position in the counter-clockwise direction being “Max cool” function, and similarly, every position from the center position to an extreme position in a clockwise direction may correspond “hot” function, with the extreme position on the clockwise direction being “Max hot” function in the HVAC system 200.
[0065] In an embodiment, the microcontroller 102a may be adapted to receive an input from the HVAC control panel for activating one of the one or more actuators 108 for controlling the AC blower speed for cabin cooling.
[0066] In yet another embodiment, the microcontroller 102a may further function as a mode control unit (MCU) which may be configured to switch between one or more modes of air flow for cabin cooling. In an embodiment, the switch scanning module 218 may receive a signal on selecting the mode on the HVAC control panel via the mode control switch 316. Accordingly, the actuator module 216 may transmit one of the plurality of control signals to the one or more actuators 108 for controlling different modes of air flow for cabin cooling. In an embodiment, the one or more modes may include a face mode, a defrost mode, and the like.
[0067] The LED switch 310 may be adapted to indicate the input selected by a user, in particular, indicating which switch is pressed by the user. For example, on selection of an AC switch by the user on the HVAC control panel, the microcontroller 102a may light up an LED indication corresponding to the AC function on the LED switch 310, indicating the activation of AC function. Similarly, on selection of a defogging switch on the HVAC control panel, the microcontroller 102a may light up an LED indication corresponding to the Defog function on the LED switch 310, indicating the activation of said defogging operation.
[0068] FIG. 4 illustrates a feedback type circuit 400 for the HVAC control unit 102, according to an embodiment of the present invention. In an embodiment, the main components for functioning of the feedback type circuit 400 may include the microcontroller 102a, the HEX Bridge driver IC 404, actuator motor 406, a potential resistor 408, internal wheels 410 of the actuators 108, and voltage feedback circuit 412.
[0069] In an embodiment, microcontroller 102a receives 5 Vdc VCC from the control unit 102 for powering the system 200. In an embodiment, the actuator module 216 of the microcontroller 102a may provide the control signal to the HEX Bridge driver IC 404. The HEX Bridge driver IC 404 may drive the actuator motor 406 by turning ON and OFF the actuator motor 406, thereby, controlling the actuators 108 as per the voltage feedback and time-based logic. Accordingly, the actuator motor 406 may receive a plurality of control signals from the HEX Bridge driver IC 404 via the potential resistor 408. The potential resistor 408 may help the actuator motor 406 to move either clockwise or counter-clockwise, as per the required direction of rotation for controlling the one or more actuators 108. In an embodiment, the feedback voltage may change as per the change in rotation of the actuator motor 406. In an embodiment, internal wheels 410 may be configured to operate the actuators 108 on rotation of the actuator motor 406 to perform the desired designated function. In an embodiment, the first node of the potential resistor 408 may be connected to 5 VDC. In an embodiment, the second node of the potential resistor 408 may be connected to the ground. In an embodiment, the third node of the potential resistor 408 may be connected to the microcontroller 102a via voltage feedback circuit 412 and is configured to sense the ADC value to the actuator feedback module 212. In a scenario, where the actuator feedback module 212 does not receive a correct value of the feedback 110, the actuator module 216 may switch from the feedback-based logic to the timer-based logic to run the one or more actuators 108. In an embodiment, the actuator module 216 may control the actuator motor 406 according to the received feedback.
[0070] In an embodiment, the actuator 108 may be connected to the microcontroller 102a of the control unit 102 via a hardwire.
[0071] FIG. 5 illustrates a flowchart depicting an exemplary method 500 for switching functioning of the actuators for the HVAC system 200, according to an embodiment of the present invention.
[0072] The method 500 may be executed, for example, by the one or more processors 202 and the one or more modules 208 located within the HVAC system 200. For the sake of brevity, constructional and operational features of the system 200 that are already explained in the description of FIG. 1, FIG. 2, FIG. 3 and FIG. 4, are not explained in detail in the description of FIG. 5.
[0073] The method 500 may begin with step 502 which may include receiving, by an actuator feedback module 212, feedback 100, 110a, and 110b from the actuators 108 at regular intervals for a first predetermined time duration.
[0074] At step 504, the method 500 may include evaluating, by a determination module 214, whether a value associated with the feedback 110, 110a, and 110b in real-time is equal to or greater than a threshold value. In an embodiment, the threshold value is equal to the value of the feedback 110, 110a, and 110b read at the initial stage of first predetermined time duration.
[0075] At step 506, the method 500 may include transmitting one of the plurality of control signals based on the evaluation, by an actuator module 216, to the actuators 108. The control signals may include a first signal to continue the feedback mechanism and to stop the actuator 108 once the actuator 108 has reached the desired position, in case of the value associated with the feedback is less than the threshold value. The control signals may include a second signal to stop the actuators 108 and switch from the feedback-based logic to a time-based logic, in case of the value associated with the feedback 110, 110a, and 110b is equal to or greater than the threshold value.
[0076] At step 508, the method 500 may include determining, by a switch scanning module 218, a current position of at least one of the plurality of switches for the time-based logic, in case of the value associated with the feedback 110, 110a, and 110b is equal to or greater than the threshold value.
[0077] At step 510, the method 500 may include determining, by the determination module 214, a direction and a time duration for a movement of the actuators 108 based on the determined current position of the at least one of the plurality of switches.
[0078] At step 512, the method 500 may include determining, by the determination module 214 a time out duration for the movement of the actuators 108 and allowing movement of the actuators 108 for a second predetermined time duration. In an embodiment, the second predetermined duration is greater than the first predetermined duration.
[0079] At step 514, the method 500 may include transmitting, by the actuator module 216 to the actuators 108, a third signal to resume the movement of the actuators 108 in the determined direction for the second predetermined time duration.
[0080] At step 516, the method 500 may include transmitting, by the actuator module 216 to the actuators 108, a fourth signal to stop the movement of the actuators 108 upon completion of the second predetermined time duration.
[0081] At step 518, the method 500 may include transmitting, by the actuator module 216 to the actuators 108, a fifth signal to restart the movement of the actuators 108 and resume the functionality based on the feedback logic.
[0082] In an embodiment, prior to receiving the feedback 110, 110a, 110b from the actuator feedback module 212, the method 500 may include scanning, by the switch scanning module 218, a current position of at least one of the plurality of switches. The method 500 may further include determining, by the determination module 214 based on a result of the scanning, whether the plurality of switches are operated by a user.
[0083] In an embodiment, the feedback 110, 110a, and 110b may be received by the actuator feedback module 212 from the actuators 108 upon the determination that the plurality of switches has been operated by the user.
[0084] FIG. 6 illustrates a flow chart of a method 600 for switching functioning of the actuators for the HVAC system 200, according to an embodiment of the present invention.
[0085] The method 600 may include a series of operation steps 602 through 624 performed by a control unit 102 and one or more constructional features of the HVAC system 200. For the sake of brevity, constructional and operational features of the system 200 that are already explained in the description of FIG. 1, FIG. 2, FIG. 3 and FIG. 4, are not explained in detail in the description of FIG. 6.
[0086] At step 602, the method 600 may include activating the HVAC system 200 of the vehicle by a user input. Said user input may be initiated by pressing a power ON switch on the control panel, or by pressing of power ON button on the handheld remote-control device.
[0087] At step 604, the method 600 may include scanning, by the switch scanning module 218 of the control unit 102, a plurality of switches. The plurality of switches may include the temperature knob 314, the rotary switch 312, and the mode control switches 316.
[0088] At step 606, the method 600 may include determining, by the determination module 214 of the control unit 102, based on a result of the scanning, whether the temperature knob 314, the rotary switch 312, and the mode control switches 316 have been pressed.
[0089] At step 608, the method 600 may include checking and performing, by the control unit 102, another task, i.e., other than regulating the temperature or airflow control, upon determination at step 606, that the temperature knob 314, the rotary switch 312, and the mode control switches 316 have not been pressed. Accordingly, the method 600 may terminate at step 608.
[0090] At step 610, the method 600 may include comparing, by the determination module 214, a feedback 110 received by the actuator feedback module 212 from one or more actuators 108, with a current position of at least one of the temperature knob 314, the rotary switch 312, and the mode control switches 316, upon determination that at step 606 at least one of the temperature knob 314, the rotary switch 312, and the mode control switches 316 had been pressed. The method 600 may further include, controlling, by the actuator module 216, the movement of the one or more actuators 108 in a direction based on the pressed switch, and the received feedback 110.
[0091] At step 612, the method 600 may include checking, by the actuator feedback module 212, the feedback from the one or more actuators 108 after a first predetermined duration. In a non-limiting example, the first predetermined duration may be of two seconds. In another non-limiting example, the first predetermined duration may be of four seconds. In yet another non-limiting example, the first predetermined duration may be any user defined time duration. The method 600 further includes determining, by the determination module 214, whether a value of the feedback 110 (current feedback ADC value) is equal to or more than a threshold value.
[0092] At step 614, the method 600 may include stopping, by transmitting the first signal by the actuator module 216, the one or more actuators 108 once the one or more actuators 108 have reached the desired position, and continuing the feedback mechanism, based on the determination by the determination module 214 that the determined value of the feedback is less than the threshold value at step 612.
[0093] At step 616, the method 600 may include stopping, by transmitting the second signal by the actuator module 216, the one or more actuators 108 and switching from the feedback-based logic to a time-based logic, based on the determination by the determination module 214 that the value of the feedback is equal to or more than the threshold value at step 612.
[0094] At step 618, the method 600 may include stopping, by transmitting the control signal by the actuator module 216, an actuator motor by sending a stop signal via servo H-bridge driver 308. Further, the method 600 may include detecting, by the switch scanning module 218, a current position of at least one of the temperature knob 314, the rotary switch 312, and the mode control switches 316.
[0095] At step 620, the method 600 may include moving the actuator motor, by the by transmitting the third signal by the actuator module 216, to control the movement of the one or more actuators 108 in the determined direction for a second predetermined time duration, based on the detected current position of at least one of the temperature knob 314, the rotary switch 312, and the mode control switches 316 by the switch scanning module 218.
[0096] At step 622, the method 600 may include stopping, by transmitting the fourth signal by the actuator module 21the movement of the one or more actuators 108 upon completion of the second determined time duration. In an embodiment, the second predetermined time duration is greater than the first predetermined time duration. In a non-limiting example, the second predetermined duration may be of four seconds. In another non-limiting example, the second predetermined duration may be of six seconds. In yet another non-limiting example, the second predetermined time duration may be of any user defined time duration.
[0097] At step 624, the flow of the method 600 stops and the control unit 102 again starts working with the feedback-based mechanism.
[0098] The present invention advantageously provide stability to the HVAC system by appropriately controlling the movements of the one or more actuators 108 in case of the absence or incorrectness of the feedback 110.
[0099] The present invention further overcomes the limitation of the conventional techniques by providing a switching functioning of the one or more actuators 108 using a time-based logic, thereby ensuring unobstructed functioning of the operations of the HVAC system even on detection of a failure of the feedback-based mechanism or absence of signal from the feedback-based mechanism of the one or more actuator 108 in the HVAC system 200.
[0100] Further, the disclosed method 500, 600 in conjunction with the HVAC system 200 proposes to switch the actuator functioning to the time-based logic when wrong feedback is received and determines the movement of the actuators based on default inputs, thereby avoiding deterioration of the user experience in case of actuator system failure.
[0101] It is understood that terms including “unit” or “module” at the end may refer to the unit for processing at least one function or operation and may be implemented in hardware, software, or a combination of hardware and software.
[0102] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.
[0103] The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein.
[0104] Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts necessarily need to be performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.
[0105] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims.
[0106] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of at least one embodiment, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein. ,CLAIMS:1. A Heating Ventilation and Air Conditioning (HVAC) system (200) for switching functioning of actuators (108) using a time-based logic, the HVAC system (200) comprising:
an actuator feedback module (212) configured to receive feedback (110, 110a, 110b) from the actuators (108) at regular intervals for a first predetermined time duration;
a determination module (214) in communication with the actuator feedback module (212), the determination module (214) configured to compare a value associated with the feedback (110, 110a, 110b) with a threshold value;
an actuator module (216) in communication with the determination module (214), the actuator module (216) configured to transmit one of a plurality of control signals to the actuators (108) based on the comparison results;
a switch scanning module (218) in communication with the determination module (214), the switch scanning module (218) configured to determine a current position of a plurality of switches;
wherein the actuator module (216) in communication with the determination module (214) is configured to switch the actuators (108) between a feedback based logic to time based logic by producing the plurality of control signals for the actuator (108) based on the determined direction and time duration of movement of the actuators (108) as well as the current position of at least one of the plurality of switches in case of detected absence or incorrectness of feedback signals (110).

2. The HVAC system (200) as claimed in claim 1, wherein the control signals produced by the actuator module (216) include:
first signal to continue the feedback mechanism and to stop the actuator (108) once the actuator (108) has reached the desired position, in case of the value associated with the feedback (110) is less than the threshold value of the feedback (110);
a second signal to stop the actuators (108) and switch from the feedback-based logic to a time-based logic, in case of the value associated with the feedback (110, 110a, 110b) is equal to or more than the threshold value;
a third control signal to resume the movement of the actuators (108) in the determined direction for a second predetermined time duration;
a fourth signal to stop the movement of the actuators (108) upon completion of the second determined time duration; and
a fifth signal to restart the movement of the actuators (108) based on the received feedback (110, 110a, 110b).

3. The system (200) as claimed in claim 1, wherein the plurality of switches associated with the HVAC system (200) include a temperature knob (314), a rotary switch (312), and mode control switches (316).

4. The HVAC system (200) as claimed in claim 1, wherein the actuator feedback module (212) receives feedback (110, 110a, 110b) from the actuators (108), upon the plurality of switches are operated by a user.

5. The HVAC system (200) as claimed in claim 1, wherein, the switch scanning module (218) is configured to scan the plurality of switches at regular intervals; and the determination module (214) is configured to determine, based on a result of the scanning, whether the plurality of switches are operated by the user.

6. A method (500) for switching functioning of actuators (108) using a time-based logic, the method (500) comprising:
receiving (502), by an actuator feedback module (212), feedback (100, 110a, 110b) from the actuators (108) at regular intervals for a first predetermined time duration,
evaluating (504), by a determination module (214), whether a value associated with the feedback (110, 110a, 110b) in real-time is equal to or greater than a threshold value;
transmitting (506) one of a plurality of control signals based on the evaluation, by an actuator module (216), to the actuators (108), the control signals include,
a first signal to continue the feedback mechanism and to stop the actuator (108) once the actuator (108) has reached the desired position, in case of the value associated with the feedback is less than the threshold value, and
a second signal to stop the actuators (108) and switch from the feedback-based logic to a time-based logic, in case of the value associated with the feedback (110, 110a, 110b) is equal to or greater than the threshold value;
determining (508), by a switch scanning module (218), a current position of at least one of the plurality of switches for the time-based logic, in case of the value associated with the feedback (110, 110a, 110b) is equal to or greater than the threshold value;
determining (510), by the determination module (214), a direction and a time duration for a movement of the actuators (108) based on the determined current position of the at least one of the plurality of switches,
determining (512), by the determination module (214) a time out duration for the movement of the actuators (108) and allow movement of actuators (108) for a second predetermined time duration;
transmitting (514), by the actuator module (216) to the actuators (108), a third signal to resume the movement of the actuators (108) in the determined direction for the second predetermined time duration;
transmitting (516), by the actuator module (216) to the actuators (108), a fourth signal to stop the movement of the actuators (108) upon completion of the second predetermined time duration; and
transmitting (518), by the actuator module (216) to the actuators (108), a fifth signal to restart the movement of the actuators (108) and resume the functionality based on the feedback logic.

7. The method (500) as claimed in claim 6, wherein the second predetermined duration is greater than the first predetermined duration.

8. The method (500) as claimed in claim 6, wherein the threshold value is equal to a value of the feedback (110, 110a, 110b) read at the initial stage of first predetermined time duration.
9. The method (500) as claimed in claim 6, wherein, prior to receiving the feedback (110, 110a, 110b) from the actuator feedback module (212), the method (500) comprising steps of:
scanning, by the switch scanning module (218), a current position of at least one of the plurality of switches; and
determining, by the determination module (214) based on a result of the scanning, whether the plurality of switches are operated by a user.

10. The method (500) as claimed in claim 6&9, wherein the feedback (110, 110a, 110b) is received by the actuator feedback module (212) from the actuators (108) upon the determination that the plurality of switches has been operated by the user.