GB2534625A

GB2534625A - Heating system and method of control

Info

Publication number: GB2534625A
Application number: GB1515567.4A
Authority: GB
Inventors: Andrew Straker James; Morris Ian; Connelly Chris; Lane Stuart
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2015-09-02
Filing date: 2015-09-02
Publication date: 2016-08-03
Anticipated expiration: 2035-09-02
Also published as: GB2534625B; GB2536571B; GB2536571A; GB201604247D0; GB201515567D0

Abstract

A heating system 101 for a vehicle comprises a window heater element 103, a vision system 111 that derives data from the environment external to the vehicle, and a controller 117. The controller 117 deactivates the window heater element 103 depending on the operational state of the vision system 111. The vision system 111 may image the environment through a portion of window 105 that is heated by element 103. Controller 117 may deactivate the element 103 during a warm-up phase of the engine. The vision system 111 may provide an error signal when it is unable to derive data about the external environment, and the controller 117 may activate the heating system on receiving this error signal. Controller 117 may determine if the vision system 111 is able to identify highway infrastructure or vehicles. The heater 103 may also be deactivated based on an external temperature. Imaging system 103 may be a road monitoring system with an imaging device attached or sealed against an interior face of the window 105.

Description

Heating System and Method of Control This disclosure relates to a heating system, and in particular, but not exclusively, relates to a heating system for a vehicle window wherein the heating system is deactivated when the window is clear.

Introduction

It is common for a vehicle to be fitted with a heated screen that can be used to help clear frost and/or snow from the screen in cold climates. However, a heated screen can place a large electrical demand on the battery and/or alternator of the vehicle, particularly as the heated screen is often used at the same time as other high power systems, such as heating, ventilation and air-conditioning (HVAC) systems, heated seats, heated mirrors, and/or positive temperature coefficient (FTC) systems.

Heated screens can be activated as a driver gets into a vehicle and turns on the engine. A large electrical power demand, for example during a warm-up phase of the vehicle, can increase fuel consumption and thus exhaust gas emissions. Furthermore, an exhaust gas after treatment system can take many minutes to warm up to its operating temperature, depending on the engine load and the ambient temperature. As a result, the efficiency of the exhaust gas after treatment system is suboptimal during the warm-up phase, which compounds the increase'in exhaust gas emissions.

A vehicle electric system can employ different strategies to manage this short term power demand with nonessential high power consumers either being turned off (load shed) or being operated on timers so they are switched off after a certain period. However, it is desirable to control a heated screen to minimise the power consumed, for example within periods of timed operation and/or load shedding, which can improve fuel consumption and reduce pollution.

Statements of Invention

According to an aspect of the present disclosure there is provided a heating system for a vehicle. The heating system comprises a window heater element, for example a heater element embedded within and/or bonded to a windscreen of a vehicle.

Operation of the heater element may increase the electrical power demand placed on an electrical system of the vehicle, which can reduce fuel economy and/or increase exhaust gas emissions whilst the heater element is operational.

The heating system may comprise a vision system configured to derive data regarding the environment external to the vehicle. For example, the vision system may be configured to determine the relative position of physical objects, such as vehicles, highway infrastructure and/or other obstacles, external to and remote from the vehicle. The vision system may be a road monitoring system. The vision system may be configured to determine climatic conditions external to the vehicle. For example, the vision system may be configured to determine if the vehicle is operating in a rainy, foggy, and/or snowy environment that reduces visibility of the driver and causes precipitation to form on a window of the vehicle.

The heating, system may comprise a controller operatively connected to the window heater element. The heating system may comprise a controller operatively connected to the vision system The controller may be configured to deactivate the window heater element depending on the operational state of the vision system. In the context of the present disclosure, the term "operational state", when applied to the vision system, is understood to mean the state in which the vision system is operable, upon activation, to derive useable data regarding the environment external to the vehicle. Usable data is defined as data of sufficient quality to be processed to provide an output to a user. For example, the data, once processed, may be used to provide an indication to a driver regarding the road conditions. However, if the data is not of sufficient quality, then it may not be possible to process the data to provide a useful output to the user. to such a circumstance, the vision system is not in an operational state.

The vision system may be configured to image the environment external to the vehicle through a window, e.g. the windscreen, of the vehicle. For example, the vision system may comprise an imaging device near to or attached to the interior face of a window of the vehicle. The imaging device may be sealed against the interior face of the window of the vehicle. The vision system may be configured to image the environment external to the vehicle through a portion of the window that is heated by the window heater element. In this manner, operation of the heater element can directly affect the operational state of the vision system by clearing precipitation, such as ice, frost and/or snow, from the portion of the window directly in front of the imaging device.

The controller may be configured to deactivate the window heater element during a warm-up phase of the vehicle. During the warm-up phase of the vehicle, an exhaust gas after treatment system of the vehicle may not have reached its optimum operating temperature. As a result, the capture and/or the conversion of exhaust gas emissions may be suboptimal during the warm-up phase. It may be beneficial, therefore, to deactivate the heater element during the warm-up phase.

The vision system may be configured to provide an error signal when it is unable to derive useable data regarding the environment external to the vehicle. For example, the error signal may be provided when the field of vision of the imaging device is at least partially obscured. The controller may be configured to activate the window heater element when the vision system provides the error signal.

The controller may be configured to determine if the vision system is operable to positively identify highway infrastructure and/or other vehicles. For example, the error signal may be provided when the vision system is unable to positively identify highway infrastructure and/or other vehicles as a result of the field of vision of the imaging device being at least partially obscured. In this state, the vision system is regarded as not operable to derive usable data The controller may be operatively connected to a temperature sensor, for example an external temperature sensor of the vehicle. The controller may be configured to determine the ambient temperature of the environment external to the vehicle using the temperature sensor. The controller may be configured to deactivate the heating system based on the temperature of the environment external to the vehicle. For example, if the heater element has been activated, for example by the driver and/or by the controller, and the controller determines that the ambient temperature is above a predetermined range of values, e.g. approximately 5° C to 10° C, then the controller may deactivate the heater element, irrespective of the operational state of the vision system.

In some circumstances, the field of vision of the vision system may be obscured by environmental debris (other than precipitation). As a result, the vision system may be unable to capture an image of the environment external to the vehicle. In order to ensure that the heater element does not remain on when the screen is clear, the controller may comprise a timed switch. The timed switch may be configured to bypass the operation of the vision system. The timed switch may be configured to deactivate the heating system after a predetermined period of operation. The timed switch may be configured to deactivate the heater element if the vision system is unable derive any usable data regarding the environment external to the vehicle with a predetermined time in the range, e.g. of 1 min to 10 min. The heating system may comprise at least one of a mirror heater element and a seat heater element. The controller may be configured to deactivate the mirror heater element and/or the seat heater element depending on the operational state of the vision system.

There is provided a vehicle comprising one or more of the above, heating systems described According to another aspect of the present disclosure there is provided method, for example a closed loop control method, of controlling a heating system for a vehicle. The heating system may comprise a window heater element. The heating system may comprise a vision system configured to derive data regarding the environment external to the vehicle. The heating system may comprise a controller operatively connected to the window heater element and the vision system. The method may comprise the step of determining the operational state of the vision system. For example, the method may comprise determining if the vision system is able to derive data, for example useable data, regarding the environment external to the vehicle. The method may comprise the step of deactivating the window heater element depending on the operational state of the vision system. For example, the method may comprise deactivating the window heater element if the vision system is operable to derive data, for example usable data, regarding the environment external to the vehicle.

The controller may be operatively connected to a temperature sensor of the vehicle.

The method may comprise the step of determining the temperature of the environment external to the vehicle. For example, the method may comprise the step of determining if the ambient temperature external to the vehicle is above a temperature at which snow, ice and/or frost is able to form on the window of the vehicle. The method may comprise the step of deactivating the heating system based on the temperature of the environment external to the vehicle.

The disclosure also provides software, such as a computer program or a computer program product for carrying out any of the methods described herein, and a computer readable medium having stored thereon a program for carrying out any of the methods described herein. A computer program embodying the disclosure may be stored on a computer-readable medium, or it could, for example, be in the form of a signal such as a downloadable data signal provided from an Internet website, or it could be in any other form.

To avoid unnecessary duplication of effort and repetition of text in the specification, certain features are described in relation to only one or several aspects or arrangements of the disclosure. However, it is to be understood that, where it is technically possible, features described in'relation to any aspect or arrangement of the disclosure may also be used with any other aspect or arrangement of the disclosure.

Brief Description of the Drawings

For a better understanding of the present disclosure, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 shows a schematic diagram of a heating system for a vehicle, and Figure 2 shows a flow chart depicting a control method for a heating system.

Detailed Description

Figure 1 shows a schematic diagram of a heating system 101 for a vehicle. The heating system 101 comprises a window heater element 103 configured to heat at least a portion of a window 105 of the vehicle. The window heater 103 can be activated by the driver to assist in defrosting and/or clearing the window in cold ambient conditions.

In figure 1, the heater element 103 is disposed, for example embedded, within the window 105. However, the heater element 103 may be attached, for example bonded, to a face of the window 105. For example, the heater element 103 may be attached to the outer face 107 and/or the inner face 109 of the window 105. The heater element 103 may be the element of a window heater configured to blow heated air across a face of the window 105. For example, the heater element 103 may be the heater element of a heating, ventilation and air-conditioning (HVAC) system of the vehicle.

The heating system 101 comprises a vision system 111 that is configured to derive data regarding the environment external to the vehicle. The vision system 111 may be configured to operate using light from the visible spectrum, infrared (IR) light, and/or ultraviolet (UV) light. For example, the vision system 111 may be a LIDAR system configured to operate using any appropriate range of wavelengths of light.

The vision system 111 may be configured to capture an image of the environment external to the vehicle through the window 105 of the vehicle, for example in order to derive data regarding the position of physical objects external to the vehicle. The vision system 111 may be a road monitoring system configured to identify highway infrastructure, such as road signs and/or lane markings, one or more other vehicles, and/or any other appropriate article remote from the vehicle. It is understood, therefore, that the point which the vision system focuses on is a point remote from the vehicle.

The vision system 111 may comprise an imaging device that is located near to the inner face 109 of the window. The imaging device may be provided in a housing 113 attached directly to the interior face 109 of the window 105. The housing 113 may be sealed against the interior face 109 of the window 105, such that the portion 115 of the window 105 through which the imaging device captures an image is protected from contamination, for example by dirt, grease and/or condensation. In this manner, the image captured by the imaging device may be affected by only the condition of the environment external to the vehicle.

In the arrangement shown in figure 1, the vision system 111 is configured to image the environment external to the vehicle through a portion of the window 105 in which the heater element 103 is embedded. In this manner, the condition of the portion 115 of the window 105 through which the imaging device captures an image may be affected by the operational state of the heater element 103. However, the heater element 103 may be configured to heat a portion of the window 103 that is spaced apart from the portion 115 of the window 105 through which the imaging device captures an image. In such a circumstance, heat energy may be transferred, for example conducted, convected and/or radiated, to the portion 115 of the window 105 in order to affect the condition of the window 105, without the heater element 103 being directly in the field of vision of the vision system 111.

The heating system 101 may comprise a controller 117 that is operatively connected to the window heater element 103 and the vision system 111. The controller is configured to deactivate the window heater element 103 depending on the operational state of the vision system 111. The vision system 111 may have a normal operational state when it is able to derive usable data regarding the environment external to the vehicle, for example when the window 103 is clear and the vision system 111 is able to capture an image of one or more articles in its field of vision. However, if the vision system 111 is unable to derive data, for example unable to positively identify an article external to the vehicle, the vision system 111 may be configured to provide an error signal, which is indicative of a change from the normal operational state of the vision system 111 In the arrangement shown in figure 1, the exterior surface 107 of the window 105 is covered with precipitation, e.g. snow 119. In particular, the portion 115 of the window 105 through which the imaging device captures an image is obscured by the snow 119. The window 105 may, however, be covered with any appropriate type of precipitation. As a result the field of vision of the imaging device is at least partially obscured by the snow 119 and the vision system 111 is unable to image the environment outside the vehicle. In such a circumstance, the heater element 103 can be activated, for example by the driver, in order to clear the snow 119 from the window 105.

When in operation, the heater element 103 can place a large electrical demand on an electrical system of She vehicle, for example a battery 121 and/or an alternator of the vehicle. The electrical demand can be particularly large as the heater element 103 is often used at the same time as other high power systems, such as heated seats, heated mirrors, and/or a heating, ventilation and air-conditioning (HVAC) system of the vehicle.

The heater element 103, and/or the other high power systems, are typically activated as a driver gets into a vehicle, turns on the engine, and prepares the vehicle for travel. As a result, a large electrical power demand is placed on the battery 121 and the alternator of the vehicle, which increases fuel consumption and thus exhaust gas emissions.

Furthermore, an exhaust gas after treatment system, such as a catalytic converter, can take some time to warm up to its operating temperature. For example, the catalytic converter may take many minutes to warm up to its operating temperature, depending on the engine load and ambient temperature. As a result, the efficiency of the exhaust gas after treatment system is sub-optimal until the catalytic converter reaches its operating temperature. As a result, not only are exhaust gas emissions increased during the warm-up phase due to the large electrical power demand of the heater element 103, but the amount of exhaust gas emissions that are converted is reduced because the catalytic converter is not working at peak efficiency.

It is desirable, therefore, to minimise the amount of time for which the heater element 103 and/or the other high power systems are activated, especially during the warm-up phase.

A controller of the vehicle's electric system can employ different open loop control strategies to manage this increased power demand whilst the heater element 103 is active, with nonessential high power consumers either being turned off (load shed) or being operated on timers so they are switched off after a certain period to safeguard against the heater element 103 being left on for extended periods of time For example, the controller 117 may comprise a timed switch configured to deactivate the heater element 103 after a certain period in order to reduce the electrical load on the battery 121. However, as the timed switch is often set for a worse-case scenario, the heater element 103 often remains activated for longer than is needed. It is desirable, therefore, to control the heater element 103 such that the heater element 103 is deactivated as soon as the window 105 is clear from snow 119 and the driver can see out of the window 105. In this manner, the electrical power demand is reduced, improving fuel consumption and reducing pollution.

The present disclosure provides a closed loop control strategy in which the vision system 111 of the vehicle determines if the window 105 of the vehicle is clear, and deactivates the heater element 103 as soon as it is no longer needed. Closed loop control of the heater element 103 using the vision system 111 is advantageous as the electrical demand placed on the battery 121 is minimised, increasing the service life of the battery 121 and reducing the cost of ownership to the customer.

The heater system 101 can, however, deliver benefits to any type of vehicle using a battery. For example, as described above, the heater system 101 can be installed in vehicles having internal combustion engines, wherein the closed loop control can be used to minimise the exhaust gas emissions during a warm-up phase. However, the heater system 101 may be installed in Hybrid Electric Vehicles (HEV), Plug-in Hybrid Electric Vehicles (PHEV) and/or Battery Electric Vehicles (BEV), or any system with large capacity High Voltage (HV) batteries. The heater system 101 can reduce the fuel consumption and the emissions on an HEV and 'a PHEV vehicle, and improve the range by which a HEV, a PHEV and a BEV may travel by reducing electrical power consumption.

Figure 2 is a flow chart that illustrates an example operational mode of the heater system 101. In figure 2, the operational state of the heater element 103 is determined by an open loop control strategy 123, which uses a timed switch, in combination with a closed loop control strategy 125 according to the present disclosure. Such a combined system is illustrative of how the closed loop control strategy 125 may be implemented into standard vehicles in order to improve upon open loop control strategies 123 that are currently used However, the heater system 101 may be controlled using only the closed loop control 125.

The operation of the heater system 101 will now be described by reference to the flow chart of figure 2. The flow chart starts at step 127 when the engine of the vehicle is turned on Discussing the standard open loop control 123 first, the driver of the vehicle activates a screen heater, for example the heater element 103, at step 129 when the window 105 is covered by snow 119. Activation of the heater element 103 starts the timed switch 131 that operates to deactivate the heater element 103 after a predetermined period. In the arrangement shown in figure 2, the open loop control 123 comprises a step 133 of demining the ambient temperature, which is used to check if the heater element 103 has been activated by mistake. For example, the heater element 103 may be deactivated immediately if the ambient temperature is above a predetermined value.

Now referring to the closed loop control 125, the activation of the vehicle's ignition system causes the vision system 111 of the vehicle to activate at step 135. The closed loop control 125 determines at step 137 if the vision system 111 is able to derive data regarding the environment external to the vehicle. If it is determined that the vision system 111 is unable to derive usable data regarding the environment external to the vehicle, for example when the window 105 is covered by snow 119, the vision system 111 provides an error signal to the controller 117. As a result, the heater element 103 is not deactivated by the controller 117. The controller 117 continues to monitor the vision system 111 at step 139 and provides a feedback signal to the determination step 137 until it is determined that the vision system 111 can positively derive usable data regarding the environment external to the vehicle. The heater element 103 is deactivated as soon as the vision system no longer provides the error signal to the controller 117, i.e. as soon as the vision system 111 can "see" out of the window 105. It may be particularly beneficial, therefore, to arrange the vision system 111 such that the field of vision of the vision system 111 is substantially similar to that of the driver of the vehicle. In this manner, the ability of the vision system 111 to determine the clarity of the window 105 is analogous to the driver being able to see out of the window 105.

The outputs from the open loop control 123 and the closed loop control 125 are combined at step 141 and the heater element 103 is deactivated at step 143 depending on the outputs of the control strategies 123, 125. For example, if the closed loop control 125 determines that the window 105 is clear before the timed switch activates, then heater element 103 is deactivated and the process terminates at step 145. In this manner, the implementation of the open loop control 123 is superseded by the closed loop control 125. As a result, the electrical power demand is reduced, which can improve, fuel consumption and reduce exhaust gas emissions, especially during the warm-up phase of a vehicle.

It will be appreciated by those skilled in the art that although the disclosure has been described by way of example with reference to one or more arrangements, it is not limited to the disclosed arrangements and that alternative arrangements could be constructed without departing from the scope of the disclosure as defined by the appended claims.

Claims

Claims 1. A heating system for a vehicle, the heating system comprising: a window heater element: a vision system configured to derive data regarding the environment external to the vehicle; and a controller operatively connected to the window heater element and the vision system, the controller being configured to deactivate the window heater element depending on the operational state of the vision system.
2. A heating system according to claim 1, wherein the vision system is configured to image the environment external to the vehicle through a window of the vehicle.
3. A heating system according to claim 1 or 2, wherein the vision system is configured to image the environment external to the vehicle through a portion of the window that is heated by the window heater element.
4. A heating system according to any of the preceding claims, wherein the controller is configured to deactivate the window heater element during a warm-up phase of an engine of the vehicle.
5. A heating system according to any of the preceding claims, wherein the vision system is configured to provide an error signal when it is unable to derive data regarding the environment external to the vehicle.
6. A heating system according to claim 5, wherein the controller is configured to activate the window heater element when the vision system provides the error signal.
7. A heating system according to any of the preceding claims, wherein the controller is configured to determine if the vision system is operable to positively identify highway infrastructure and/or other vehicles.
8. A heating system according to any of the preceding claims, wherein the controller is operatively connected to an external temperature sensor of the vehicle, the controller being further configured to: determine the temperature of the environment external to the vehicle; and deactivate the heating system based on the temperature of the environment external to the vehicle.
9. A heating system according to any of the preceding claims, wherein the heating system further comprises at least one of a mirror heater element and a seat heater element, the controller being configured to deactivate the mirror heater element and/or the seat heater element depending on the operational state of the vision system.
10. A heating system according to any of the preceding claims, wherein the vision system comprises a road monitoring system having an imaging device attached directly to the interior face of a window of the vehicle.
11. A heating system according to claim 10, wherein the imaging device is sealed against the interior face of the window of the vehicle.
12. A heating system according to any of the preceding claims, wherein the controller comprises a timer configured to deactivate the heating system after a predetermined period of operation.
13. A heating system according to any of the preceding claims, wherein the window heater element is attached to a face of a window and/or is at least partially within the window of the vehicle.
14. A vehicle comprising one or more heating systems of any of claims 1 to 13.
15. A method of controlling a heating system for a vehicle, the heating system comprising: a window heater element; a vision system configured to derive data regarding the environment external to the vehicle; and a controller operatively connected to the window heater element and the vision system, the method comprising the steps of: determining the operational state of the vision system; and deactivating the window heater element depending on the operational state of the vision system.
16. A method according to claim 15, wherein the controller is operatively connected to a temperature sensor of the vehicle, the method further comprising: determining the temperature of the environment external to the vehicle; and deactivating the heating system based on the temperature of the environment external to the vehicle.
17. A method according to any of claims 15 or 16, the method further comprising deactivating the heating system during a warm-up phase of the engine.
18. A heating system controller as described herein, with reference to, and as shown in the accompanying drawings.
19. A method of controlling a heating system as described herein, with reference to, and as shown in the accompanying drawings.Amendment to the claims have been filed as follows: Claims 1. A heating system for a vehicle, the heating system comprising: a window heater element; a vision system configured to derive data regarding the environment external to the vehicle and to provide an error signal when it is unable to derive data regarding the environment external to the vehicle; and a controller operatively connected to the window heater element and the vision system, the controller being configured to deactivate the window heater element when the vision system does not provide the error signal.2. A heating system according to claim 1, wherein the vision system is configured to image the environment external to the vehicle through a window of the vehicle.3. A heating system according to claim 1 or 2, wherein the vision system is cr) configured to image the environment external to the vehicle through a portion of CO 20 is configured to deactivate the window heater element during a warm-up phase C\I of an engine of the vehicle.5. A heating system according to claim 1, wherein the controller is configured to activate the window heater element when the vision system provides the error signal.6. A heating system according to any of the preceding claims, wherein the controller is configured to determine if the vision system is operable to positively identify highway infrastructure and/or other vehicles.7. A heating system according to any of the preceding claims, wherein the controller is operatively connected to an external temperature sensor of the vehicle, the controller being further configured to: determine the temperature of the environment external to the vehicle; and deactivate the heating system based on the temperature of the environment external to the vehicle.the window that is heated by the window heater element.OCO4. A heating system according to any of the preceding claims, wherein the controller 8. A heating system according to any of the preceding claims, wherein the heating system further comprises at least one of a mirror heater element and a seat heater element, the controller being configured to deactivate the mirror heater element and/or the seat heater element depending on the operational state of the vision system.9. A heating system according to any of the preceding claims, wherein the vision system comprises a road monitoring system having an imaging device attached directly to an interior face of a window of the vehicle.10. A heating system according to claim 9, wherein the imaging device is sealed against the interior face of the window of the vehicle.11. A heating system according to any of the preceding claims, wherein the controller comprises a timer configured to deactivate the heating system after a (r) predetermined period of operation.12. A heating system according to any of the preceding claims, wherein the window heater element is attached to a face of a window and/or is at least partially within CO the window of the vehicle.13. A vehicle comprising one or more heating systems of any of claims 1 to 12.14. A method of controlling a heating system for a vehicle, the heating system comprising: a window heater element; a vision system configured to derive data regarding the environment external to the vehicle and to provide an error signal when it is unable to derive data regarding the environment external to the vehicle; and a controller operatively connected to the window heater element and the vision system, the method comprising the steps of: determining if the vision system provides the error signal; and deactivating the window heater element when the vision system does not provide the error signal.15. A method according to claim 14, wherein the controller is operatively connected to a temperature sensor of the vehicle, the method further comprising: determining the temperature of the environment external to the vehicle; and deactivating the heating system based on the temperature of the environment external to the vehicle.16. A method according to any of claims 14 or 15, the method further comprising deactivating the heating system during a warm-up phase of an engine of the vehicle.17. A heating system controller as described herein, with reference to, and as shown in the accompanying drawings.18. A method of controlling a heating system as described herein, with reference to, and as shown in the accompanying drawings.CO