System for electrically heating a vehicle windshield

Abstract

A system (10) for electrically heating glass configured to be installed in a vehicle is provided, and includes a transparent metal layer (14) attached to the glass and configured to conduct an electric current and increase in temperature in response to the electric current passing through it to heat the glass, a glass temperature sensor (40) configured to sense the glass temperature of the glass, a humidity sensor (44) configured to sense at least one of the humidity inside the vehicle and the humidity outside the vehicle, an interior temperature sensor (42) configured to sense the temperature inside the vehicle, an exterior temperature sensor (42) configured to sense the temperature outside the vehicle, and a control module.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to a system for electrically heating a vehicle windshield or other glass surface. [Background technology]

[0002] This section provides background art related to the disclosure, but is not necessarily prior art.

[0003] Traditionally, vehicle windshields are defrosted, de-iced, and / or defogging by blowing hot air onto the windshield from the vehicle's HVAC system vents to heat the glass. Ice or frost that forms on the windshield is heated by the hot air from the HVAC system vents, causing the heat from the windshield glass to melt. Similarly, windshield frost is removed by warming the glass to a temperature above the current dew point of the vehicle's environment. However, defrosting, deicing, and / or defogging a vehicle windshield using hot air from an HVAC system can take a long time and consume a large amount of energy. For example, defrosting a car windshield using hot air from an HVAC system can take 20 to 30 minutes and consume 5.2 kilowatt-hours (kWh) of energy. Therefore, a faster and more energy-efficient method and system is needed. Summary of the Invention

[0004] This section provides a summary of the disclosure and is not an exhaustive disclosure of the entire scope or all features of the disclosure.

[0005] The present disclosure includes a system for electrically heating glass configured to be mounted in a vehicle. The system includes: a transparent metal layer mounted on the glass and configured to conduct an electric current and increase in temperature in response to the electric current passing through the transparent metal layer to heat the glass; a glass temperature sensor configured to sense a glass temperature of the glass; a humidity sensor configured to sense at least one of an interior humidity of the vehicle and an exterior humidity outside the vehicle; an interior temperature sensor configured to sense an interior temperature of the vehicle; an exterior temperature sensor configured to sense an exterior temperature outside the vehicle; and a control module. The control module is configured to receive inputs from at least one of the glass temperature sensor, the humidity sensor, the interior temperature sensor, the exterior temperature sensor, an occupant detection system, and a vehicle speed sensor, determine a corrective action based on at least one of the inputs received from the glass temperature sensor, the humidity sensor, the interior temperature sensor, the exterior temperature sensor, the occupant detection system, and the vehicle speed sensor, and control the current to the transparent metal layer based on the inputs and the corrective action.

[0006] The present disclosure also includes a system for electrically heating glass configured to be mounted in a vehicle. The system includes a transparent metal layer configured to be mounted adjacent to the glass, a power source, and a control module. The control module is configured to communicate with a glass temperature sensor configured to sense a temperature of the glass, communicate with at least one of an interior temperature sensor configured to sense a temperature inside the vehicle and an exterior temperature sensor configured to sense a temperature outside the vehicle, receive the glass temperature from the glass temperature sensor, receive at least one of an interior temperature from the interior temperature sensor, an exterior temperature from the exterior temperature sensor, and a humidity value of the interior or exterior humidity, calculate a dew point based on at least one of the interior temperature, the exterior temperature, and the humidity value, and periodically apply a voltage from the power source to the transparent metal layer based on the glass temperature and the dew point to heat the glass.

[0007] The present disclosure also includes a system for electrically heating glass configured to be mounted in a vehicle, the system including: a transparent metal layer mounted on the glass and selectively connected to a battery, the transparent metal layer conducting electrical current, the transparent metal layer configured to increase in temperature in response to electrical current passing through the transparent metal layer to heat the glass; a vehicle heating system configured to selectively heat the battery and an interior of the vehicle; and a control module configured to selectively connect the transparent metal layer to the battery and activate the vehicle heating system to heat the battery without heating the interior and without connecting the transparent metal layer to the battery during a first period of time, deactivate the vehicle heating system during a second period of time following the first period, connect the transparent metal layer to the battery to heat the transparent metal layer and the glass, and decouple the transparent metal layer from the battery and activate the vehicle heating system to heat the interior without heating the battery during a third period of time following the second period of time.

[0008] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. The drawings described herein are merely illustrative of selected embodiments and do not represent all practical possibilities and are not intended to limit the scope of the disclosure. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 illustrates an exemplary system according to the present disclosure for electrically heating a vehicle windshield or other glass surface. [Figure 2] FIG. 2 illustrates an exemplary vehicle including the system of the present disclosure. [Figure 3] FIG. 3 illustrates layers of an exemplary windshield including a transparent metal layer according to the present disclosure. [Figure 4] FIG. 4 is a diagram illustrating various control modules and systems of the present disclosure. [Figure 5]FIG. 5 illustrates the system of the present disclosure in conjunction with an exemplary vehicle refrigeration / heating circuit. [Figure 6] FIG. 6 illustrates an exemplary control algorithm according to the present disclosure configured to defog (and prevent) a vehicle windshield or other glass surface. DETAILED DESCRIPTION OF THE INVENTION

[0010] Corresponding reference characters indicate corresponding parts throughout the several drawing figures.

[0011] Exemplary embodiments will now be described in more detail with reference to the accompanying drawings.

[0012] The present disclosure includes systems and methods for defrosting, deicing, and / or defogging a vehicle windshield and / or other glass surfaces (e.g., side windows, rear windows, glass roofs, etc.) by passing an electric current through the windshield and / or other glass surfaces.

[0013] Any suitable system for applying electrical current may be used, such as, but not limited to, a pulsed electrothermal de-icing (PETD) heater system. The present disclosure is applicable to heating vehicle glass as well as non-vehicle glass. Thus, the present disclosure is not limited to automotive applications. The present disclosure is applicable to any glass surface requiring defogging, deicing, defrosting, etc.

[0014] The present disclosure includes systems and methods configured to quickly and efficiently defrost, de-ice, and / or defog a vehicle windshield by applying a voltage to a transparent metal layer of the windshield to heat the windshield. Heat is generated by a PETD heater system or other suitable system configured to pass an electric current through or across the vehicle windshield and / or other glass surface. The heat generated by the electric current passing through the transparent metal layer of the windshield heats the windshield, thereby defrosting, de-icing, and / or defogging the vehicle windshield. For example, the PETD heater system can quickly heat the windshield, melting any ice that has formed on the windshield and separating the remaining ice from the windshield with a layer of water. Once the layer of water has formed between the windshield and the remaining ice, the vehicle's wipers can be activated to remove the remaining ice from the windshield. For example, in one embodiment, defrosting a windshield using a PETD heater system according to the present disclosure takes less than one minute and consumes 0.12 kWh of energy, compared to the 20 to 30 minutes and 5.2 kWh required for conventional systems that use hot air from an HVAC system, resulting in significant time and energy savings.

[0015] PETD heater systems and related concepts are shown and described in the following patents, which are incorporated herein by reference in their entireties: U.S. Pat. No. 6,870,139, entitled "System and Method for Modifying Ice-Object Interface," U.S. Pat. No. 8,921,739, entitled "System and Method for Windshield De-Icing," U.S. Pat. No. 10,473,381, entitled "High Frequency Automatic Defrost Evaporator Coil," and U.S. Pat. No. 11,229,091, entitled "Continuous Resistance and Proximity Check for High Power De-Icing and Defogging Systems."

[0016] 1-3, an exemplary PETD heater system 10 for a windshield 12 of a vehicle 30 is shown. The PETD heater system 10 includes a transparent metal layer 14 (also referred to as a transparent metal sheet) embedded within the windshield 12. As shown in FIG. 3, the transparent metal layer 14 may be sandwiched between one or more layers 32 of glass and / or polyvinyl butyral (PVB) shatter-resistant plastic. While the example of FIG. 3 includes a single transparent metal layer 14 between the glass or PVB layers 32, other configurations using additional transparent metal layers 14 and / or additional glass or PVB layers are also possible. The transparent metal layer 14 of the windshield 12 may also be used to reflect infrared solar energy from the interior of the vehicle 30.

[0017] The transparent metal layer 14 is connected to bus bars 16, 17 on the opposite side. While FIG. 1 shows the bus bars 16, 17 located on the left and right sides of the transparent metal layer 14, the bus bars 16, 17 may alternatively be located on the top and bottom of the transparent metal layer 14 or in other suitable locations. The bus bars 16, 17 are connected to a PETD control module 18 via wires 20, 21. The PETD control module 18 is connected to a power source 24 and a communication bus 26, such as a controller area network (CAN) bus. The PETD control module 18 may be, for example, an electronic control unit (ECU) and may communicate with other ECUs or other devices or components of the vehicle 30 using the communication bus 26. The PETD control module 18 may be and / or include a controller, microcontroller, microcomputer, or other computing device with a processor, memory, and / or other hardware and circuitry configured to control the PETD heater system 10 in accordance with the present disclosure.

[0018] The power source 24 may be one or more batteries of the vehicle 30. For example, in an electric vehicle, the power source 24 may be a 400 to 900 volt battery. In a hybrid vehicle, the power source 24 may be a 36 volt battery. In an internal combustion engine vehicle, the power source 24 may be a 12 volt battery. Although specific examples of batteries are shown, any suitable voltage battery may be used.

[0019] To activate the PETD heater system 10 to defrost, de-ice, and / or defog the vehicle windshield 12, the PETD control module 18 applies a voltage to the bus bars 16, 17 by connecting the wires 20, 21 to the power source 24. As shown in FIG. 1 , the wire 20 and the bus bar 16 are at the positive terminal and the wire 21 and the bus bar 17 are at the negative terminal, creating a voltage difference between the bus bars 16, 17, causing a current to flow from the power source 24 to the bus bars 16, 17 and across the transparent metal layer 14. The control module 18 includes one or more switches, as needed, to control and apply a voltage to the wires 20, 21 and the bus bars 16, 17. The voltage difference causes a current to flow through the transparent metal layer 14, heating it, which in turn heats other layers of the windshield 12, such as the glass / PVB layer 32. The voltage applied to the bus bars 16, 17 and the transparent metal layer 14 can be pulsed using a duty cycle or applied continuously until the PETD heater system 10 is turned off.

[0020] In this manner, the PETD control module 18 controls the voltage applied to the bus bars 16, 17 and the flow of current through the transparent metal layer 14 to heat the windshield 12. As discussed above, the heat from the windshield 12 may melt any thin layer of ice that has formed on the windshield 12, forming a thin layer of water between the windshield 12 and the ice remaining on the windshield 12. At that point, the wipers of the vehicle 30 may be activated to clear any ice remaining on the windshield 12. Similarly, once the windshield 12 is heated above the current dew point of the vehicle 30's environment, the heat from the windshield 12 may also dissipate any fog or condensation that has formed on the windshield 12.

[0021] 1 and 4, in one embodiment, the vehicle 30 may be equipped with a heat pump system 50 in addition to the PETD heater system 10. For example, the heat pump system 50 may include conventional components such as a compressor, a condenser, an expansion valve, an evaporator, etc., for transferring heat from the exterior of the vehicle 30 to the interior thereof to heat the interior of the vehicle 30. Further, more specifically, the heat pump system 50 may be configured to supply heat to a power source 24, such as a battery, of the vehicle 30, as indicated by double arrow 51. Additionally, the heat pump system 50 may be configured to supply heat to a vehicle interior 66, as indicated by double arrow 67.

[0022] The vehicle 30 may include a startup control module 52 that communicates with the PETD control module 18 and the heat pump system 50 via the communication bus 26. The startup control module 52 is configured to control the transition to an operational state and the operating sequence of the PETD heater system 10 and the heat pump system 50 upon startup. The battery temperature sensor 54 is configured to sense the temperature of the power source 24, such as a battery, of the vehicle 30 and may communicate the battery temperature to the startup control module 52 via the communication bus 26.

[0023] Additionally, environmental sensors 40, 42, 44, and 46 are shown in communication with the PETD control module 18 to provide environmental parameter data to the PETD control module 18. For example, the PETD heater system 10 may include a windshield temperature sensor 40 that senses the temperature of the windshield 12 and communicates data indicative of the windshield temperature to the PETD control module 18. The PETD heater system 10 may also include an outdoor ambient temperature sensor 42 that senses the outdoor ambient exterior temperature of the environment surrounding the vehicle 30 and communicates data indicative of the outdoor ambient exterior temperature to the PETD control module 18. The PETD heater system 10 may also include a humidity sensor 44 that senses the humidity of the air in the environment surrounding the vehicle 30 and / or the air inside the vehicle and communicates data indicative of the humidity to the PETD control module 18. The PETD heater system 10 may also include an interior temperature sensor 42 that senses the interior temperature within the vehicle 30 and communicates data indicative of the interior temperature to the PETD control module 18.

[0024] The humidity sensor 44 may be, for example, an optical sensor located behind the rearview mirror of the vehicle 30, which optically senses condensation or fogging that forms on the windshield 12 of the vehicle 30. For example, the optical sensor may sense the amount of ambient exterior light that is able to pass through the windshield 12 and determine humidity based on the amount of light. The humidity sensor 44 may assign a humidity data value based on the amount of light that is able to pass through the windshield. Additionally or alternatively, the system 10 may be configured to receive current outdoor humidity and / or dew point measurements from an appropriate third-party weather reporting agency, such as an appropriate commercial, governmental, or private weather reporting agency. For example, the system 10 may include any suitable receiver 48 configured to receive weather forecasts that include humidity and dew point measurements. The receiver may be configured to receive any suitable signal, such as, but not limited to, cellular, AM / FM, or satellite. Although sensors 40, 42, 44, 46 and receiver 48 are shown in direct communication with PETD control module 18, sensors 40, 42, 44, 46 and receiver 48 may communicate with PETD control module 18 or other system components or modules via communication bus 26.

[0025] For efficient operation, the temperature of the vehicle 30 battery typically must exceed a predetermined temperature threshold. Therefore, the start-up control module 52 may prioritize heating the battery before activating other components and systems, such as the PETD heater system 10. For example, the start-up control module 52 may receive the battery temperature from the battery temperature sensor 54 and activate the heat pump system 50 to heat the battery for a predetermined amount of time or until the battery temperature exceeds a predetermined temperature.

[0026] Once the battery of the vehicle 30 reaches a predetermined temperature threshold, the startup control module 52 can prioritize defrosting of the windshield 12. Thus, the startup control module 52 can deactivate the heat pump system 50 and activate the PETD heater system 10 to heat and defrost the windshield 12. For example, the startup control module 52 can instruct the PETD control module 18, via communication over the communication bus 26, to apply a voltage to the transparent metal layer 14 to heat the windshield 12 for a predetermined period of time or until the windshield 12 reaches a predetermined temperature sensed by the windshield temperature sensor 40. Once the windshield 12 has been heated and defrosted by the PETD heater system 10, the startup control module 52 can deactivate the PETD heater system 10 and reactivate the heat pump system 50 to provide heat to the interior of the vehicle 30.

[0027] As shown in FIG. 1 , the windshield 12 may include portions that are not covered by the transparent metal layer 14. For example, some sensors, such as LIDAR sensors or cameras, may not be able to properly sense conditions outside the windshield 12 through the transparent metal layer 14. Therefore, the transparent metal layer 14 may include a window 60 that does not include the transparent metal layer 14. A sensor, such as a LIDAR sensor or a camera, may be located behind the window 60. For example, such a sensor may be attached to a rearview mirror attached to the windshield 12.

[0028] Because the portion of the windshield 12 corresponding to the window 60 is not heated by the PETD heater system 10, the vehicle 30 may include an additional heater system for heating the portion of the windshield 12 corresponding to the window 60. For example, a carbon nanotube-based (CNB) heater system 62, also known as a carbon nanotube (CNT) heater, may be used to heat the portion of the windshield 12 corresponding to the window 60. An example of a CNB heater is the CNB heater system available from Canatu. The CNB heater system 62 may include a film or sheet layer of carbon nanotubes positioned and layered on the windshield 12 at a location corresponding to the window 60. The carbon nanotubes in the CNB heater system 62 are then heated by a heat source to locally heat the portion of the windshield corresponding to the window 60. The CNB heater system 62 may communicate with the start control module 52 via the communication bus 26.

[0029] The vehicle 30 may also include a radiant heater system 64 configured to provide radiant heat to occupants of the vehicle 30. For example, the radiant heater system 64 may be located in a footwell or within the dashboard of the vehicle to provide radiant heat to the feet, legs, torso, or face of one or more occupants of the vehicle 30. The CNB heater system 62 may communicate with the start control module 52 via the communication bus 26.

[0030] The startup control module 52 may be configured to control, upon startup, the PETD heater system 10, the heat pump system 50, the CNB heater system 62, and the radiant heater system 64 according to Table 1 below.

[0031] [Table 1]

[0032] Using the startup control logic shown in Table 1, the startup control module 52 can operate the heat pump system 50 for a first period to heat only the power source 24, i.e., the vehicle battery. As shown in Table 1, during the first period, the PETD heater system 10, the CNB heater system 62, and the radiant heater system 64 are turned off, and the heat pump system 50 is turned on only to heat the battery, not the entire interior 66 of the vehicle 30. Once the battery temperature reaches a predetermined threshold, the startup control module 52 proceeds to a second period. During the second period, the PETD heater system 10, the CNB heater system 62, and the radiant heater system 64 are all turned on, and the heat pump system 50 is turned off. The second period is sufficient time to defrost the windshield 12. For example, the second period may be one minute. After the second period ends, the startup control module 52 proceeds to a third period. During the third time period, the PETD heater system 10 and the battery heat pump system 50 are turned off. However, the heat pump system 50 is turned on to heat the interior 66 of the vehicle 30. Additionally, during the third time period, the CNB heater system 62 and the radiant heater system 64 can be turned on or off as needed depending on the heating needs of the vehicle 30 and / or the user of the vehicle 30.

[0033] Alternatively, if initial heating of the battery of the vehicle 30 is not required, the initial heating of the battery by the heat pump system 50 can be omitted. In this configuration, the startup control module 52 can control the system components at startup based on the control logic shown in Table 2.

[0034] [Table 2]

[0035] Using the startup control logic shown in Table 2, the startup control module 52 can operate for a first time period by turning on the PETD heater system 10, the CNB heater system 62, and the radiant heater system 64 and turning off the heat pump system 50. The first time period is sufficient to defrost the windshield 12. For example, the first time period may be one minute. After the first time period ends, the startup control module 52 proceeds to a second time period. During the second time period, the PETD heater system 10 and the battery heat pump system 50 are turned off. However, the heat pump system 50 remains on to heat the interior 66 of the vehicle 30. Furthermore, during the second time period, the CNB heater system 62 and the radiant heater system 64 can be turned on or off as needed depending on the heating needs of the vehicle 30 and / or the user of the vehicle 30.

[0036] The activation control logic can also be used to determine when to activate the vehicle's 30 wipers to clear ice from the windshield 12 once the PETD heater system 10 has melted the ice layer and formed a layer of water between the windshield 12 and the remaining ice. For example, the activation control logic may include activating the wipers once the PETD heater system 10 is deactivated or when the activation of the PETD heater system 10 has ended. Additionally or alternatively, the PETD control module 18 can monitor system conditions, including the temperature of the windshield 12, to determine whether a sufficient layer of water has formed, at which point the windshield wipers can be automatically activated. Additionally or alternatively, the system can include a camera or image sensor that monitors the color of the ice and frost on the windshield 12. Once the color of the ice and frost has changed sufficiently, the PETD control module 18 determines that a layer of water has formed and activates the windshield wipers. Additionally or alternatively, the activation control logic may prevent the windshield wipers from being activated while the PETD heater system 10 is activated and / or until a predetermined initial period has elapsed after the PETD heater system 10 is activated and / or while the vehicle 30 is stationary.

[0037] 1 and 4 , vehicle 30 may include a communications module 68 that communicates data from vehicle 30 to other systems external to vehicle 30. For example, vehicle communications module 68 may communicate with a cloud-based AI / machine learning system 70. AI / machine learning system 70 includes a data collection / communications module 72 configured to communicate with vehicle 30 communications module 68.

[0038] In particular, the data collection / communication module 72 can collect and receive all kinds of operational data and setpoints from the vehicle 30 related to the operation of the vehicle 30, such as the vehicle's 30 speed and GPS location. The vehicle's 30 GPS location can be used to determine the vehicle's position relative to sea level. In this manner, various control strategies and parameters can be updated and modified in real time to account for the vehicle's 30 location. In this manner, different control strategies and parameters can be used depending on whether the vehicle 30 is at or near sea level or at a higher elevation or altitude, such as in mountainous terrain. The data collection / communication module 72 can also receive operational data related to setpoints and various temperatures, pressures, etc. related to the operation of the PETD heater system 10, the heat pump system 50, the CNB heater system 62, and the radiant heater system 64 (e.g., windshield temperature data, outdoor ambient exterior temperature data, indoor ambient interior temperature data, humidity data, etc.). The data collection / communication module 72 may also receive data related to the power source 24, such as the vehicle's battery, and data related to the power consumption required for the operation of various vehicle systems. The data collection / communication module 72 may also receive data related to the occupancy of the vehicle, such as data from occupancy sensors, data from infrared (IR) sensors, and / or data from cameras within the vehicle 30.

[0039] All data collected from the vehicle is utilized by a parameter optimization module 74 of the AI / machine learning system 70 to calculate and determine optimized operating parameters. These parameters are transmitted back to the vehicle 30 for use in operating various vehicle systems, such as the PETD heater system 10, the heat pump system 50, the CNB heater system 62, and the radiant heater system 64. Additionally, the optimized operating parameters can be utilized by the startup control module 52 to determine optimized setpoints and time periods for startup control algorithms that control the activation and deactivation of various vehicle systems. For example, the parameter optimization module 74 can input the data collected from the vehicle 30 into one or more AI / machine learning models 76 stored in the cloud-based AI / machine learning system 70 to determine optimized parameters and setpoints for the various vehicle systems of the vehicle 30. The optimized parameters and setpoints are transmitted back to the vehicle's communications module 68 in real time by the data collection / communications module 72. The communications module 68 can communicate optimized parameters and set points to various vehicle systems and ECUs to improve the operation and efficiency of the various vehicle systems.

[0040] In this manner, various vehicle system control logic, setpoint times and thresholds, setpoint temperatures and thresholds, etc., can be optimized based on vehicle system data monitored, collected, and processed in real time by the cloud-based AI / machine learning system 70. The cloud-based AI / machine learning system 70 can also provide real-time control of various vehicle systems. The AI / machine learning system 70 may also include control logic for filtering and determining what types of data from one or more vehicles 30 or vehicle systems are allowed to be incorporated and incorporated into the AI / machine learning model 76. In addition to real-time adjustments, the AI / machine learning system 70 can collect data from multiple vehicles 30 over time, determine optimization parameters and strategies, and send them as updates to the multiple vehicles 30.

[0041] Another feature is that, because the heat pump system 50 and / or the HVAC system are not required to defrost the vehicle's windshield 12, heat from the heat pump system 50 and / or the HVAC system can be diverted to heat the vehicle's 30 battery during startup. Additionally or alternatively, during startup, all heat from the heat pump system 50 and / or the HVAC system can be diverted to first heat the vehicle's 30 battery before heating the vehicle's 30 interior. As shown in FIG. 5, the vehicle 30 may be equipped with multiple refrigeration / heating circuits, such as a hot water circuit, a refrigerant circuit, and a chilled water circuit. The hot water circuit can be used to operate an interior heater 80 that provides heat to the vehicle's 30 interior. As shown in FIG. 5, the heat pump system may include a diversion path 82 that diverts hot water from the hot water circuit to the vehicle's 30 battery 84 to heat the battery. For example, during startup, a control valve can control the flow of hot water so that the hot water does not flow to the interior heater 80 but instead flows to the battery 84 via the diversion circuit 82. Once startup is complete and the battery 84 is sufficiently heated, the diversion circuit 82 is closed, and the control valve 90 redirects the hot water in the hot water circuit back to the interior heater 80 to heat the interior of the vehicle 30. Additionally or alternatively, a second diversion path can be used to direct hot water from the hot water circuit to the exterior heat exchanger. In this manner, because the PETD heater system 10 can be used to defrost the windshield 12 of the vehicle 30, hot water from the hot water circuit of the heat pump system 50 can be diverted to heat the battery 84 and / or the exterior heat exchanger 92 of the heat pump system 50. In this manner, optimal system temperature is quickly achieved. Additionally, because the heat pump system 50 is not required to defrost the windshield 12, the heat pump system 50 can be sized to account for the reduced heating capacity required during startup.

[0042] As another feature, the PETD heater system 10 can be configured to operate at two different voltages, allowing the amount of voltage applied to the transparent metal layer 14 to be selected. For example, the PETD heater system 10 can use pulse width modulation and duty cycle to control the effective voltage applied to the transparent metal layer 14. For example, the normal or high voltage of the power supply 24 can be periodically applied to the transparent metal layer using pulse width modulation and duty cycle so that the effective voltage received by and applied to the transparent metal layer is substantially lower than the normal or high voltage of the power supply 24. Further, for example, when the PETD heater system 10 is defrosting the windshield 12, the normal or high voltage of the power supply 24 can be applied without pulse width modulation. Furthermore, the PETD control module 18 can use pulse width modulation and duty cycle to apply a reduced effective voltage to the transparent metal layer when the PETD heater system 10 is being used to defog the windshield 12.

[0043] 1, the PETD control module 18 is in communication with an occupant detection system 110 of the vehicle 30 and a vehicle speed sensor 120. The occupant detection system 110 includes any suitable sensors configured to identify whether an occupant is present within the vehicle 30. For example, the occupant detection system 110 may include any suitable camera sensor pointed at a seat of the vehicle 30 and / or a pressure sensor within the seat of the vehicle 30. The vehicle speed sensor 120 is configured to detect whether the vehicle 30 is moving and the speed of the vehicle 30. Any suitable speed sensor may be incorporated.

[0044] The PETD control module 18 is configured to vary the voltage of the PETD heater system 10 based on whether the vehicle 30 is moving and whether an occupant is present in the vehicle 30. For example, based on inputs from the occupant detection system 110 and the vehicle speed sensor 120, the normal voltage or high voltage of the power source 24 can be applied when the vehicle 30 is unoccupied or stationary. Otherwise, a reduced effective voltage is applied. This protects the occupants in the event of an accident or if the crash detection or high voltage cut-off systems fail.

[0045] In hot and humid environments, such as Florida, the dew point may reach a relatively high value, such as 78°F. During the night, the outdoor temperature may drop, and then in the morning, the ambient temperature may rise again rapidly, such as to 85°F, while the humidity may be relatively high, such as 95%. In such a situation, when a user drives a vehicle, the windshield may remain at a low overnight temperature, potentially resulting in significant condensation and fogging. To remove the fogging and condensation that occurs in such a situation, a user would traditionally need to activate the heater and defroster to heat the windshield and remove the fogging. Because the outdoor temperature is relatively high, such as 85°F, a user may not want to run the heater at such a high outdoor temperature. In such a scenario, the PETD heater system 10 can be used to heat the windshield 12 without activating the defrost function of the vehicle's HVAC system. Additionally, a user can use the PETD heater system 10 to heat the windshield to defog the windshield and cool the interior of the vehicle 30 to a comfortable temperature for the user while operating the air conditioning function of the HVAC system of the vehicle 30. Furthermore, for example, the PETD heater system 10 can monitor the outdoor ambient temperature sensed by the outdoor temperature sensor 42 and the humidity sensed by the humidity sensor 44 (and / or the outdoor humidity and dew point reported by any suitable weather reporting service transmitted to the vehicle and received by the receiver 48), calculate the current dew point, and operate the PETD heater system 10 to heat the windshield to a temperature above the dew point. Simultaneously, the HVAC system of the vehicle 30 can be operated to cool the temperature to a cooling setpoint determined by the HVAC system or selected by the user. In other embodiments, the PETD heater system 10 can also be used on interior windows of a building to defog or condense the windows of the building without heating the building's interior.

[0046] 6 illustrates a control algorithm for the PETD heater system 10. The control algorithm can be executed and implemented by the PETD control module 18 or other suitable computing device configured to perform the illustrated functions and communicate with the described sensors and components. The control algorithm begins at step 500. In step 502, the PETD control module 18 receives ambient outdoor temperature and humidity data from the temperature sensors 42, 46 and humidity data from the humidity sensor 44. Outdoor humidity and / or dew point data may be received via the receiver 48 from an external source transmitting a weather forecast. In step 504, the PETD control module 18 receives the windshield temperature from the windshield temperature sensor 44. In step 506, the PETD control module 18 calculates the current dew point or obtains the dew point from the weather forecast. In step 508, the PETD control module 18 compares the windshield 12 temperature with the current dew point temperature. In step 508, if the temperature of the windshield 12 is below the dew point (or less than a predetermined range of the dew point, e.g., within + / - 2°C of the dew point), the PETD control module 18 proceeds to step 510 and applies a voltage to the transparent metal layer 14 to activate or turn on the PETD heater to heat the windshield. In step 508, if the temperature of the windshield 12 is greater than or equal to the dew point (or less than or equal to + / - 2°C of the dew point), the PETD control module 18 proceeds to step 512 and either takes no action or deactivates the PETD heater if it was previously activated. After steps 510 and 512, the PETD control module returns to step 502.

[0047] In one embodiment, the PETD heater system 10 can be activated to periodically activate the PETD heating of the windshield 12 while the vehicle is parked to heat the windshield 12 and prevent ice or frost from forming on the windshield 12 while the vehicle is parked. For example, the PETD control module 18 can periodically apply a voltage to the transparent metal layer 14 at predetermined time intervals, such as using a timer, to maintain the windshield 12 above a predetermined threshold temperature while the vehicle is parked. For example, the PETD heater system 10 can be configured to maintain the windshield 12 above freezing to prevent ice or frost from forming on the windshield 12.

[0048] The predetermined time interval for activating and operating the PETD heater system 10 can be preset, such as every one minute, every two minutes, every five minutes, or any other suitable time interval. Alternatively, the predetermined time interval can be calculated and determined based on sensed parameters related to the vehicle environment, such as the outdoor ambient temperature sensed by the ambient outdoor temperature sensor 42, the humidity of the vehicle environment sensed by the humidity sensor 44 or reported in a weather forecast received by the receiver 48, and / or the temperature of the windshield 12 sensed by the windshield temperature sensor 40. The PETD control module 18 communicates with the appropriate sensors, as shown in FIG. 1, as needed, to receive data related to the various sensed parameters.

[0049] Additionally or alternatively, the PETD control module 18 can operate the PETD heater system 10 to heat the windshield 12 based on sensed parameters, such as the ambient outdoor temperature and humidity of the environment and / or the temperature of the windshield. For example, the PETD control module 18 can monitor the temperature of the windshield 12 sensed by the windshield temperature sensor 40 and, once the temperature of the windshield 12 falls below a predetermined threshold, activate the PETD heater system 10 to apply a voltage to the transparent metal layer 14 to maintain the temperature of the windshield 12 above the predetermined threshold. For example, the PETD control module 18 can use a proportional-integral-derivative (PID) control algorithm based on the sensed temperature of the windshield 12 and a target temperature threshold for the windshield 12. Other suitable control algorithms can also be used. Additionally or alternatively, a duty cycle D can be used to periodically activate the PETD heater system 10 using pulse width modulation to activate the PETD heater system 10 for a calculated portion of the period T.

[0050] Additionally or alternatively, PETD control module 18 can receive the outdoor ambient temperature sensed by outdoor exterior temperature sensor 42, the humidity sensed by humidity sensor 44, and / or the humidity listed in a weather forecast received by receiver 48, and the interior temperature sensed by interior temperature sensor 46 to calculate the current dew point of the vehicle's 30 environment. PETD control module 18 can periodically operate PETD heater system 10 to heat and maintain the temperature of windshield 12 above the current dew point (or above a predetermined range of the dew point, e.g., + / - 2°C) to prevent fogging or condensation from forming on the windshield. For example, PETD control module 18 can use a PID control algorithm or another suitable control algorithm to determine the duty cycle for applying voltage to transparent metal layer 14 to heat windshield 12.

[0051] In one embodiment, the control period can be relatively long, such as five minutes, during which the PETD heater system 10 may heat the windshield 12 to a temperature a few degrees, e.g., four or five degrees, above the current dew point, and then allow the windshield to cool to a temperature closer to the current dew point before reactivating the heater system. In another embodiment, the control period can be relatively short, such as one minute, in which case the PETD heater system 10 may heat the windshield 12 to a temperature one or two degrees above the current dew point and continuously maintain the temperature of the windshield 12 at a temperature one or two degrees above the current dew point.

[0052] In embodiments in which the PETD heater system 10 is installed in an electric or hybrid vehicle, different control strategies may be used depending on whether the vehicle 30 is plugged in and charging and / or whether shore power is available to the PETD heater system 10. For example, in one embodiment, the PETD heater system 10 may be configured to heat the windshield 12 of the vehicle 30 to prevent ice, frost, and fogging only when the vehicle 30 is parked and plugged in, and may be configured not to operate when the vehicle 30 is parked but unplugged. Additionally or alternatively, the PETD heater system 10 may be configured to heat the windshield 12 using a first control strategy with first control parameters when the vehicle 30 is parked and plugged in, and to heat the windshield 12 using a second control strategy with second control parameters when the vehicle 30 is parked and unplugged. The second control strategy and second control parameters can be configured to use less power and energy than the first control strategy and first control parameters. Additionally or alternatively, the PETD heater system 10 can be configured to monitor the remaining battery charge of the vehicle 30 and can utilize a different control strategy based on the remaining battery charge of the vehicle 30. For example, if the remaining battery charge of the vehicle 30 is below a predetermined threshold, the PETD heater system 10 can switch to a more energy-efficient control strategy and / or prevent further heating of the windshield 12 of the vehicle 30 using the PETD heater system 10.

[0053] Additionally or alternatively, the PETD heater system 10 can be configured to preheat the windshield 12 of the vehicle 30 based on a known or determined schedule of the user of the vehicle 30. For example, the PETD heater system 10 can be configured to determine that the user will leave for work at a predetermined time, such as 8:00 a.m. each morning. In such a case, the PETD heater system 10 can be activated and begin heating the windshield 12 a predetermined time before the user's expected departure time. The PETD heater system 10 may also determine that the user has plugged in the vehicle when the user arrives at work. In such a case, the PETD heater system 10 can monitor the current charge of the battery of the vehicle 30 and operate the PETD heater system 10 to predict that the user will arrive at work and the battery of the vehicle 30 will be recharged. Further for example, the PETD heater system 10 can be configured to continuously heat the windshield 12 while the vehicle 30 is plugged in, and then switch to a control strategy based on the vehicle user's habits and schedule, i.e., departure time and expected charging time, when the vehicle 30 is unplugged.

[0054] Additionally or alternatively, the PETD heater system 10 may be configured to use shore power only when the vehicle 30 is plugged in, and not to operate on battery power from the vehicle 30. In other words, the PETD heater system 10 may be configured to operate only on shore power, and not on power from the battery of the vehicle 30. In this manner, the PETD heater system 10 can prevent draining the battery of the vehicle 30.

[0055] The PETD heater system 10 may be configured with a proximity sensor to sense and determine if the vehicle 30 is near a heat-emitting object such as a building, tree, etc. The PETD heater system 10 may be configured to optimize its operation to take into account heat emitted by objects in the vehicle's 30 environment.

[0056] In a vehicle 30 equipped with both a PETD heater system 10 and an HVAC system with a defrost function, the PETD heater system 10 can be configured to operate first, prior to operation of the defrost function of the HVAC system of the vehicle 30. For example, while the PETD heater system 10 is operating to defrost, de-ice, or defog the windshield 12, the PETD heater system 10 can be operated to disable and inhibit operation of the defrost function of the HVAC system.

[0057] Additionally or alternatively, the control algorithm may include additional checks and strategies based on whether the vehicle 30 is connected to shore power, the current state of charge of the vehicle's battery, the schedule or habits of the vehicle's user, etc., as described above.

[0058] The foregoing description is merely exemplary in nature and in no way limits the disclosure, its application, or uses. The broad teachings of this disclosure can be embodied in a variety of forms. Accordingly, while this disclosure includes certain embodiments, it should not be limited thereto, as the true scope of this disclosure will be apparent from the drawings, specification, and claims. It should be understood that one or more steps in a method may be performed in a different order (or simultaneously) without altering the principles of this disclosure. Furthermore, although each embodiment is described above as having particular features, any one or more of the features described with respect to any embodiment of this disclosure may be implemented in place of any feature of the other embodiments and / or with a combination of features, even if such combinations of features are not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitutions and modifications of one or more embodiments for one another are within the scope of this disclosure.

[0059] Spatial and functional relationships between elements (e.g., between modules) are described using various terms such as "connected," "involved," "interface," "coupled," etc. Unless expressly stated as "direct," when a relationship between a first element and a second element is described in the above disclosure, the relationship may be a direct relationship where there are no other intervening elements between the first element and the second element, or an indirect relationship (both spatially and functionally) where there are one or more intervening elements between the first element and the second element.

[0060] As used herein, the phrase "at least one of A, B, and C" shall be interpreted to mean a non-exclusive logical OR (AORBOR). For example, the phrase "at least one of A, B, and C" shall be interpreted to include (i) A only, (ii) B only, (iii) C only, (iv) both A and B, (v) both A and C, (vi) both B and C, and (vii) both A, B, and C. The phrase "at least one of A, B, and C" should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0061] In the drawings, the direction of the arrow, as indicated by the arrow symbol, generally indicates the flow of information (such as data or instructions) that is significant in the illustration. For example, if element A and element B exchange various information, but information sent from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This one-way arrow does not imply that other information is not sent from element B to element A. Furthermore, in the case of information sent from element A to element B, element B may send a request for or acknowledgement of receipt of the information to element A. The term component does not necessarily require a proper component. In other words, a first component part of a first part may be coextensive (equal) with the first part.

[0062] In this application, including the definitions below, the term "module" or "controller" may be interchanged with the term "electronic device" or the term "circuitry." The term "module" or "controller" refers to, is part of, or includes a hardware processor (which may be shared, dedicated, or a group) for executing code, and a hardware memory (which may be shared, dedicated, or a group) that stores code executed by the hardware processor.

[0063] A module or controller may include one or more interface circuits. In some examples, the interface circuit may implement a wired or wireless interface connected to a local area network (LAN) or a wireless personal area network (WPAN). Examples of LANs include the Institute of Electrical and Electronics Engineers (IEEE) Standard 802.11-2016 (also known as the WIFI wireless networking standard) and IEEE Standard 802.3-2015 (also known as the ETHERNET wired networking standard). Examples of WPANs include the IEEE Standard 802.15.4 (including the ZigBee Alliance's ZIGBEE standard) and the Bluetooth Special Interest Group's (SIG) BLUETOOTH wireless networking standard (including the Bluetooth SIG's Core Specification Versions 3.0, 4.0, 4.1, 4.2, 5.0, and 5.1).

[0064] Modules or controllers can communicate with other modules or controllers using interface circuits. While this disclosure depicts modules or controllers as logically communicating directly with other modules or controllers, in various implementations, modules or controllers may actually communicate through a communication system. A communication system may include physical and / or virtual network devices such as hubs, switches, routers, and gateways. In some implementations, a communication system may connect to or traverse a wide area network (WAN) such as the Internet. For example, a communication system may include multiple LANs interconnected via the Internet or point-to-point leased lines using technologies such as Multiprotocol Label Switching (MPLS) or Virtual Private Networks (VPNs).

[0065] In various implementations, the functionality of a module or controller may be distributed among multiple modules connected via a communication system. For example, multiple modules may implement the same functionality distributed by a load balancing system. In yet another example, the functionality of a module or controller may be split between a server (also called remote or cloud) module and a client (or user) module. For example, a client module may include a native application or a web application running on a client device and in network communication with a server module.

[0066] The term "code," as described above, can include software, firmware, and / or microcode and can refer to programs, routines, functions, classes, data structures, and / or objects. Shared processor hardware includes a single microprocessor that executes some or all code from multiple modules or controllers. Group processor hardware includes a microprocessor that executes some or all code from one or more modules in combination with additional microprocessors. Multiple microprocessors can refer to multiple microprocessors on separate dies, multiple microprocessors on a single die, multiple cores of a single microprocessor, multiple threads of a single microprocessor, or a combination thereof.

[0067] Shared memory hardware includes a single memory device that stores some or all of the code for multiple modules. Group memory hardware includes a memory device that, in combination with other memory devices, stores some or all of the code for one or more modules.

[0068] The term "hardware memory" is part of the term computer-readable medium. The term "computer-readable medium" does not encompass transitory electrical or electromagnetic signals propagating through a medium such as on a carrier wave, and therefore the term "computer-readable medium" is interpreted as tangible and non-transitory (non-transient). Non-limiting examples of non-transitory computer-readable media are non-volatile memory devices (e.g., flash memory devices, erasable programmable read-only memory devices, or masked read-only memory devices), volatile memory devices (e.g., static random access memory devices or dynamic random access memory devices), magnetic storage media (e.g., analog or digital magnetic tape or hard disk drives), or optical storage media (e.g., CDs, DVDs, or Blu-ray discs).

[0069] The apparatus and methods described in this application may be implemented partially or completely by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. The functional blocks and flowchart elements described above function as software specifications and can be converted into a computer program by the routine work of a skilled engineer or programmer.

[0070] A computer program includes processor-executable instructions stored on at least one non-transitory computer-readable medium. A computer program may include or rely on stored data. Computer programs include a basic input / output system (BIOS) that interacts with hardware in a special-purpose computer, device drivers that interact with specific devices in a special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0071] Computer programs include, but are not limited to, (i) HTML (HyperText Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, and (v) source code compiled and executed by a just-in-time compiler. By way of example, the source code may be written using the following languages: C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.

[0072] The exemplary embodiments are provided so that this disclosure will be thorough and will fully convey its scope to those skilled in the art. Many specific details are set forth, such as examples of specific components, devices, and methods, to provide a thorough understanding of the embodiments of this disclosure. It will be apparent to those skilled in the art that specific details need not be employed, and that the exemplary embodiments can be embodied in many different forms, none of which should be construed as limiting the scope of this disclosure. In some exemplary embodiments, well-known processes (method steps), well-known device structures, and well-known technologies are not described in detail.

[0073] The terminology used in this specification is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used in this specification, the singular forms (definite and indefinite articles) are intended to include the plural forms unless the context clearly dictates otherwise. The terms "comprise," "have," "include," and "have" are inclusive and thus specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The steps, processes, and operations of methodologies described in this specification should not be construed as necessarily requiring the particular order described or illustrated, unless specifically identified as such. It should also be understood that additional or alternative steps may be used.

Claims

1. 1. A system for electrically heating glass configured for installation in a vehicle, comprising: a transparent metal layer (14) attached to the glass and conducting an electric current, the transparent metal layer being configured to increase in temperature in response to the electric current passing therethrough, thereby heating the glass; a glass temperature sensor (40) configured to sense a glass temperature of the glass; a humidity sensor (44) configured to sense at least one of the vehicle's interior humidity and the vehicle's exterior humidity; an interior temperature sensor (42) configured to sense an interior temperature of the vehicle; an exterior temperature sensor (42) configured to sense an exterior temperature outside the vehicle; and a control module, the control module comprising: receiving inputs from at least one of the glass temperature sensor, the humidity sensor, the interior temperature sensor, the exterior temperature sensor, an occupant detection system (110), and a vehicle speed sensor (120); determining a corrective action based on at least one of the inputs received from at least one of the glass temperature sensor, the humidity sensor, the interior temperature sensor, the exterior temperature sensor, the occupant detection system, and the vehicle speed sensor; A system configured to control current to the transparent metal layer based on at least one of the input and the corrective action.

2. 10. The system of claim 1 further comprising: The glass is configured as a windshield (12).

3. 3. The system according to claim 1 or 2, The glass is configured as one of a side window of the vehicle, a rear window of the vehicle, and a roof of the vehicle.

4. 4. The system according to claim 1, wherein: The transparent metal layer is attached between the first and second layers of glass.

5. 5. The system according to claim 1, wherein: The control module is configured as a pulsed electric thermal de-icing (PETD) control module (18) and is configured to control current to the transparent metal layer to de-ice the glass.

6. The system according to any one of claims 1 to 5, further comprising: The transparent metal layer and the control module are electrically connected to bus bars (16, 17), the bus bars being configured to distribute current to the transparent metal layer.

7. 7. The system according to claim 1, In performing the corrective action, the control module: applying a direct current to the transparent metal layer at a first voltage when inputs from the occupant detection system and the vehicle speed sensor indicate that the vehicle is unoccupied or the vehicle is stationary; When inputs from the occupant detection system and the vehicle speed sensor indicate that the vehicle is occupied and moving, a direct current is passed through the transparent metal layer at a second voltage lower than the first voltage.

8. 8. The system according to claim 1, In performing the corrective action, the control module: calculating a dew point based on at least one of the indoor temperature, the outdoor temperature, the outdoor humidity, and the indoor humidity; A voltage is periodically applied to the transparent metal layer from a power source (24) to heat the glass based on the glass temperature and the dew point.

9. The system of any one of claims 1 to 8, further comprising: A receiver (48) is provided that is configured to receive a weather forecast including a dew point.

10. 10. The system of claim 9, The control module is configured to control current to the transparent metal layer to heat the glass until the glass temperature is above a predetermined temperature range that includes the dew point.

11. 1. A system for electrically heating glass configured for installation in a vehicle, comprising: a transparent metal layer (14) configured to be attached adjacent to said glass; a power source (24), and a control module, the control module comprising: in communication with a glass temperature sensor (40) configured to sense the temperature of the glass; communicating with at least one of an interior temperature sensor (42) configured to sense a temperature inside the vehicle and an exterior temperature sensor (42) configured to sense a temperature outside the vehicle; receiving a glass temperature from the glass temperature sensor; receiving at least one of the temperature inside the vehicle from the indoor temperature sensor, the temperature outside the vehicle from the outdoor temperature sensor, and a humidity value of the humidity inside or outside the vehicle; calculating a dew point based on at least one of the interior temperature, the exterior temperature, and the humidity value; The system is configured to periodically apply a voltage from the power source to the transparent metal layer based on the glass temperature and the dew point to heat the glass.

12. 12. The system of claim 11, The glass is configured as one of a windshield (12), a side window of the vehicle, a rear window of the vehicle, and a roof of the vehicle.

13. 13. The system according to claim 11 or 12, The control module is configured to control the voltage effective to the current to the transparent metal layer by pulse width modulation and duty cycle control.

14. 14. The system according to any one of claims 11 to 13, The control module is configured to obtain a humidity value from a weather forecast transmitted to the control module.

15. 15. The system according to any one of claims 11 to 14, The control module further comprises: receiving input from an ice / frost sensor configured to sense ice and frost conditions on the glass; When input from the ice / frost sensor indicates that the ice or frost conditions are such that they can be removed by the wipers, the wipers are activated to wipe the windshield.

16. 1. A system for electrically heating glass configured for installation in a vehicle, comprising: a transparent metal layer (14) attached to the glass and selectively connected to a battery, the transparent metal layer conducting an electric current, the transparent metal layer being configured to increase in temperature in response to the electric current passing therethrough, thereby heating the glass; a vehicle heating system configured to selectively heat the battery and an interior of the vehicle; and a control module, the control module comprising: selectively connecting the transparent metal layer to the battery; activating the vehicle heating system to heat the battery without heating the interior of the vehicle and without connecting the transparent metal layer to the battery during a first period of time; during a second period of time after the first period of time, deactivating the vehicle heating system and connecting the transparent metal layer to the battery to heat the transparent metal layer and the glass; The system is configured to disconnect the transparent metal layer from the battery during a third period of time after the second period of time and activate the vehicle heating system to heat the interior of the vehicle without heating the battery.

17. 17. The system of claim 16, The vehicle heating system includes a heat pump system (50) configured to heat at least one of the battery and the passenger compartment.

18. 18. The system of claim 17, further comprising: a radiant heater system (64) configured to heat an occupant of the vehicle; The control module is configured to activate the radiant heater system during the second period and deactivate the radiant heater system during the first period.

19. 20. The system of claim 18, further comprising: a carbon nanotube heater system (62) configured to heat at least a portion of the glass that is not heated by the transparent metal layer; The control module is configured to activate the carbon nanotube heater system during the second period of time and deactivate the carbon nanotube heater system during the first period of time.

20. 20. The system of any one of claims 16 to 19, The control module is configured as a pulsed electric thermal de-icing (PETD) control module (18) and is configured to control the current to the transparent metal layer by pulse width modulation and duty cycle control to control the effective voltage of the current to the transparent metal layer.

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