Vehicle interior lighting system

Abstract

The present invention relates to an interior lighting system for a vehicle, the vehicle comprising an opaque roof, the opaque roof comprising an outer surface exposed to an environment surrounding the vehicle and an inner surface exposed to an interior volume of the vehicle. The interior lighting system comprises a sensor device configured to infer at least one characteristic of light incident on a section of the outer surface of the opaque roof of the vehicle. The interior lighting system further comprises a lighting device configured to emit light from the section of the inner surface of the opaque roof of the vehicle into the interior volume of the vehicle. The interior lighting system comprises a control device connected to the sensor device and the lighting device, the control device configured to control the lighting device such that the at least one characteristic of light emitted from the section of the inner surface mimics the at least one characteristic of light incident on the section of the outer surface of the opaque roof inferred by the sensor device, the section of the outer surface of the opaque roof of the vehicle corresponding to the section of the inner surface of the opaque roof of the vehicle. The present invention further relates to a computer-implemented method for controlling an interior lighting system of a vehicle, and a computer program comprising instructions that, when executed by a computing device, cause the computing device to perform steps of the computer-implemented method.

Description

[Technical field]

[0001] The present invention relates to a vehicle having an opaque roof, an interior volume for accommodating passengers, and a lighting system for illuminating at least a portion of the interior volume. [Background technology]

[0002] Most vehicles have a roof which is either transparent or opaque.

[0003] A transparent roof typically comprises glass or other transparent areas that allow outside light to pass through and enter the interior of the vehicle, which is appreciated by many passengers as it gives them a better connection with the environment.

[0004] The present invention relates to vehicles with opaque roofs and aims to give passengers a similar connection to the environment as with a transparent roof, which is appreciated for vehicles where a transparent roof cannot be used, for example because the roof is part of a photovoltaic system (PV system) such as that used in the Lightyear One commercially available from Atlas Technologies BV of Helmond, The Netherlands.

[0005] It should be noted that most vehicles with transparent or opaque roofs have interior lighting, used for example for reading maps when parked at night, etc. Preferably these are dimmed while driving to improve the driver's night vision.

[0006] Document WO2015 / 026296 describes an apparatus for providing lighting in the interior of a vehicle. The apparatus comprises input means arranged to provide input data that varies depending on the environment around the vehicle. The input data is processed to determine characteristics of the lighting to be provided. The apparatus comprises output means arranged to provide lighting in the interior of the vehicle with determined characteristics. The characteristics of the output means match the characteristics of the environment around the vehicle when the lighting is provided. In a particular embodiment, the output means comprises an LED strip aligned along a roof liner. Images are repeatedly acquired by a camera through each window of the vehicle and associated with groups of LEDs along a portion of the LED strip above the window. First, a region of interest is selected from the image. The region of interest is then divided into a number of segments. The number of segments is equal to the number of LEDs corresponding to the image, such that the lighting characteristics determined for each segment are projected by the associated LEDs along the LED strip. In other words, the characteristics of the light in the image are used to determine the characteristics of the lighting to be provided. Images are captured by the camera through each window. Thus, the illumination of the LEDs along the LED strip is determined based on the light seen through each window. The LED strips around the perimeter of the window then emit light having the determined characteristics, effectively "extending" the light seen through the window to the area surrounding the window.

[0007] A drawback of the system described in WO2015 / 026296 is that it cannot be used to determine and project illumination characteristics of opaque surfaces, such as, for example, an opaque roof of a vehicle. The system of WO2015 / 026296 simply provides a system in which the characteristics of light entering a vehicle through a window are used to determine the characteristics of light emitted by a light source within the vehicle. Thus, light already visible inside the vehicle is "projected" onto other parts of the vehicle's interior, effectively "extending" such light to parts of the vehicle that were previously unreachable. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] WO2015 / 026296 [Patent Document 2] European Patent Application EP2933699A1 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention is intended to overcome one or more of the shortcomings of conventional interior vehicle lighting systems, or at least provide an alternative to conventional interior vehicle lighting systems. The present invention is intended to combine the advantages of a transparent roof with the benefits of an opaque roof. [Means for solving the problem]

[0010] In a first aspect, the present invention relates to an interior lighting system for a vehicle, the vehicle comprising an opaque roof, the opaque roof having an exterior surface exposed to an environment surrounding the vehicle and an interior surface exposed to an interior volume of the vehicle, the interior lighting system comprising: A sensor device configured to infer at least one characteristic of light incident on a section of an outer surface of an opaque roof of a vehicle; - a lighting device configured to emit light from a section of an inner surface of an opaque roof of the vehicle into an interior volume of the vehicle; a control device connected to the sensor device and the lighting device, the control device being configured to control the lighting device such that at least one characteristic of light emitted from the section of the inner surface of the opaque roof mimics at least one characteristic of light incident on the section of the outer surface of the opaque roof as inferred by the sensor device; Equipped with A section of the outer surface of the opaque roof of the vehicle is associated with a section of the inner surface of the opaque roof of the vehicle.

[0011] The interior lighting system may be arranged to illuminate the interior of a vehicle. The vehicle may include an interior volume, e.g., a cabin in which a person may sit. For example, the person sitting in the cabin may be the driver and / or passenger of the vehicle. The vehicle may include an opaque roof, i.e., external light may be able to transmit little or no light through the opaque roof. The opaque roof may include a relatively small transmitting portion, e.g., a conventional sunroof. This is in contrast to a transparent roof, in which at least a portion of the external light may transmit through the opaque roof to illuminate the interior volume of the vehicle. For example, the opaque roof may completely cover the interior volume. As another example, the opaque roof may be in contact with a windshield and / or a rear window and / or a side window. In many examples, the vehicle has at least a windshield through which the driver can see outside. In some examples, the vehicle does not have a rear window, and thus the opaque roof extends completely toward the rear end of the vehicle. In such examples, the opaque roof may be hinged such that the opaque roof includes a portion that serves as a panel for the trunk of the vehicle. Due to the opacity of the roof, exterior light may illuminate the interior volume exclusively through the vehicle's windows and windshield and rear windshield, or in some cases through a relatively small transparent portion of the roof, such as a conventional sunroof.

[0012] The opaque roof comprises an exterior surface and an interior surface. The exterior surface of the opaque roof is exposed to the environment around the vehicle. When the vehicle is traveling outdoors, the environment includes natural elements such as trees, animals including birds, clouds, the sun, and artificial elements such as street lights, buildings, and bridges. The light incident on the vehicle is either direct or indirect sunlight, or light emitted by artificial elements such as street lights. Outdoor light (e.g., coming from the sun during the day or, e.g., from street lights at night) may be at least partially blocked by natural elements such as trees, or artificial elements such as bridges or buildings. When the vehicle is traveling indoors, the environment includes equivalent natural and artificial elements. However, the light incident on the vehicle when traveling indoors is either indirect light (transmitted through surfaces such as building windows) or artificial light (coming from a light source such as indoor lighting). The exterior surface of the opaque roof, exposed to the environment around the vehicle, is exposed to exterior lighting coming from natural and artificial elements.

[0013] The inner surface of the opaque roof is at least partially exposed to the interior volume of the vehicle, for example, the inner surface of the opaque roof is fully exposed to the interior volume of the vehicle, in other words, the inner surface of the opaque roof is visible to anyone within the interior volume of the vehicle.

[0014] The interior lighting system comprises a sensor device. The sensor device is configured to estimate at least one characteristic of light incident on a section of an opaque roof outer surface of the vehicle. In some examples, the sensor device is configured to estimate a plurality of characteristics of light incident on a section of an opaque roof outer surface of the vehicle. For example, the section of the opaque roof outer surface is a rectangular area of ​​the opaque roof outer surface. For example, the opaque roof outer surface comprises a plurality of equally sized rectangular portions. As another example, the opaque roof outer surface comprises a single section, i.e., the opaque roof outer surface section surrounds the opaque roof outer surface. The at least one characteristic of light includes light intensity, which may be, for example, a luminance of a light source and / or an illuminance of light incident on the section of the opaque roof outer surface. For example, the illuminance is expressed in lux, i.e., lumens per square meter. The at least one characteristic of light includes, for example, a color of light. For example, the color of light is expressed as a red / green / blue (RGB) value. The sensor device in some examples is equipped directly to measure characteristics of light incident on a section of the exterior surface of the opaque roof. For example, the sensor device is a lux meter disposed at or near the section of the exterior surface of the opaque roof, the lux meter adapted to measure illuminance. As another example, the sensor measures irradiance (W / cm 2In one embodiment, the spectrometer is adapted to measure several characteristics of the light incident on the outer surface section of the opaque roof, such as the light intensity (lux or fc), radiance (W / sr), luminance (cd), luminous flux (lumens or watts), chromaticity, and color temperature. To infer at least one characteristic of the light incident on the outer surface section, the sensor device, for example, directly measures at least one characteristic of the light incident on the outer surface section, i.e., the directly measured characteristic is used as the inferred characteristic. In another example, the sensor device infers the light incident on the outer surface section by indirect measurement. For example, the sensor device is disposed outside the outer surface section. In such a case, the sensor device measures at least one characteristic of the light incident on the sensor device. The sensor device then infers at least one characteristic of the light incident on the outer surface section by converting the at least one characteristic of the light incident on the sensor device. For example, the sensor device buffers several direct measurements over time and, based on the vehicle's speed and the distance of the sensor device relative to the section of the exterior surface, infers that the direct measurement of at least one characteristic of light incident on the sensor device is at least one characteristic of light incident on the section of the exterior surface at a later point in time.

[0015] The interior lighting system comprises a lighting device. The lighting device is configured to emit light from a section of the inner surface of the vehicle's opaque roof into the interior volume of the vehicle. For example, the lighting device is disposed along the inner surface of the opaque roof. For example, the lighting device comprises one or more LED strips mounted on or embedded within the inner surface of the opaque roof. As another example, the lighting device comprises a lighting panel mounted on or embedded within the inner surface of the opaque roof. The lighting device in some examples comprises a single light source, which is controllable to emit light. In some other examples, the lighting device comprises multiple light sources, which are individually addressable and therefore individually controllable to emit light. Thus, in such examples, at least one characteristic of the light emitted from the section of the inner surface by the lighting device is spatially controllable. In other words, within the lighting device, each light source of the multiple light sources can emit light having different characteristics. The inner surface of the vehicle's opaque roof is, for example, divided into equal sized portions, which are, for example, rectangular, and which are, for example, square.

[0016] The lighting system comprises a control device connected to the sensor device and the lighting device. The control device is configured to control the lighting device such that at least one characteristic of the light emitted from the section of the inner surface mimics at least one characteristic of the light incident on the section of the outer surface of the opaque roof inferred by the sensor device. To mimic the at least one characteristic of the light incident on the section of the outer surface of the opaque roof inferred by the sensor device, the control device is configured, for example, to control the lighting device such that the lighting device emits light having at least one characteristic in common with the characteristic inferred by the sensor device, optionally all characteristics. In another example, to mimic the at least one characteristic of the light incident on the section of the outer surface of the opaque roof inferred by the sensor device, the control device is configured to control the lighting device such that the lighting device emits light having at least one characteristic that is a linear transformation of the characteristic inferred by the sensor device. In this example, for example, the sensor device is configured to infer the color of the light incident on the section of the outer surface in a full RGB color space, while the lighting device emits light in which the color of the light is converted to grayscale.

[0017] The partition of the outer surface of the vehicle's opaque roof is associated with the partition of the inner surface of the vehicle's opaque roof. Thus, the inferred at least one characteristic of the light incident on the partition of the outer surface is used by the controller to control the lighting device. The partition of the outer surface and the partition of the inner surface may, for example, be the same size and have the same position on the opaque roof, and thus there is a one-to-one correspondence between the partition of the outer surface and the partition of the inner surface. In another example, the partition of the outer surface surrounds the partition of the inner surface, i.e. there is a one-to-n correspondence between the partition of the outer surface and the partition of the inner surface. Thus, in this example, the partition of the inner surface is smaller than the partition of the outer surface. In yet another example, the partition of the inner surface surrounds the partition of the outer surface, i.e. there is a one-to-n correspondence between the partition of the inner surface and the partition of the outer surface.

[0018] By controlling the lighting device in such a manner as to mimic at least one characteristic of light incident on a section of the outer surface of the opaque roof, the effect of the roof being transparent is created. For example, a person within the interior volume of the vehicle looking at the inner surface of the opaque roof is observing light being emitted by the lighting device from the section of the inner surface of the opaque roof and has the impression of looking through the opaque roof because the emitted light mimics at least one characteristic of light incident on the section of the outer surface of the opaque roof.

[0019] In an embodiment according to the first aspect of the invention, the opaque roof comprises a plurality of roof sections, the roof sections being arranged in a pattern, each roof section of the opaque roof comprising a corresponding section of an outer surface of the opaque roof and a corresponding section of an inner surface of the opaque roof.

[0020] For example, the outer surface of the opaque roof has the same pattern of sections as the inner surface of the opaque roof. For example, the roof section is rectangular, meaning that the section on the inner surface is rectangular and the section on the outer surface is rectangular. For example, the roof section is square, meaning that the section on the inner surface is square and the section on the outer surface is square.

[0021] In some examples, the sections of the outer surface and the sections of the inner surface are the same size, meaning that the inner surface comprises the same number of sections as the number of sections constituted by the outer surface. In such a configuration, each section of the inner surface is the same size as the corresponding section of the outer surface at the corresponding position, i.e., the section of the inner surface is located directly below the corresponding section of the outer surface. In other examples, each section of the outer surface contains multiple corresponding sections of the inner surface. In other words, the section of the inner surface is smaller than the section of the outer surface, and multiple sections of the inner surface are contained within each section of the outer surface. In other examples, each section of the inner surface contains multiple corresponding sections of the outer surface. In other words, the section of the inner surface is larger than the section of the outer surface, and multiple sections of the outer surface are contained within each section of the inner surface.

[0022] The partitions of the outer surface define the outer resolution and the partitions of the inner surface define the inner resolution. The outer resolution defines the accuracy with which the light incident on the opaque roof is estimated. The light incident on each partition of the outer surface is estimated by the sensor device. Thus, by increasing the number of partitions of the outer surface, the outer resolution is increased and the accuracy with which the light incident on the opaque roof is estimated increases. In other words, by increasing the number of partitions of the outer surface, the sensor device estimates more values ​​representing the light incident on the opaque roof, i.e., one value per partition of the outer surface. Similarly, the inner resolution defines the accuracy with which at least one characteristic of the light incident on the outer surface of the opaque roof is mimicked by the control device. By increasing the number of partitions of the inner surface, the inner resolution is increased and the accuracy with which at least one characteristic of the light incident on the outer surface of the opaque roof is mimicked by the control device by emitting light from the inner surface. In other words, by increasing the number of partitions of the inner surface, more values ​​representing the light incident on the opaque roof can be mimicked, i.e., one value per partition of the inner surface.

[0023] Optionally, in this embodiment, the roof sections are arranged in a grid pattern, for example, the grid pattern defines a rectangle, in other words, the grid pattern defines a rectangular area of ​​opaque roof, the rectangle comprising a plurality of roof sections.

[0024] Optionally, in this embodiment, the interior lighting system comprises as many lighting devices as there are roof sections, each lighting device configured to emit light from a respective section of the inner surface of the opaque roof.

[0025] In other words, a separate and distinct lighting device emits light from each section of the interior surface. Thus, the lighting devices correspond to the pattern of the roof sections. Since there are multiple roof sections, the number of lighting devices is at least two. In some examples, the interior surface is covered or formed by the lighting devices.

[0026] Optionally, in this embodiment, the sensor device is configured to infer at least one characteristic of light incident on each section of the outer surface of the opaque roof, and the control device is configured to control each lighting device such that the at least one characteristic of light emitted by the respective lighting device mimics the at least one characteristic of light incident on the respective section of the outer surface of the opaque roof.

[0027] In other words, at least one characteristic of light incident on an area of ​​the outer surface defined by the pattern of the roof section is inferred by the sensor device. The inferred at least one characteristic of light incident on an area of ​​the outer surface is mimicked by emitting light from a corresponding area of ​​the inner surface. The effect of mimicking a transparent roof is enhanced by increasing the outer resolution and / or the inner resolution.

[0028] Optionally, in this embodiment, the interior lighting system comprises a number of sensor devices equal to the number of roof sections, each sensor device configured to infer at least one characteristic of light incident on a respective section of the outer surface of the opaque roof.

[0029] For example, the sensor device is located in or on the outer surface section of each roof section. Thus, there is a one-to-one relationship between the sensor device and the roof section. Such a setup ensures that the computational cost of inferring at least one characteristic of the light incident on each section of the outer surface of the opaque roof is reduced since the sensor device is located close to the outer surface section. Thereby, the sensor device infers at least one characteristic of the light incident on each section of the outer surface of the opaque roof by directly measuring the at least one characteristic.

[0030] In an embodiment according to the first aspect of the invention, the sensor device is configured to infer at least one characteristic of light incident on a section of an outer surface of an opaque roof of a vehicle with an update frequency of 25 Hz or greater.

[0031] Optionally, in this embodiment, the control device is configured to control the lighting device with an update frequency of 25 Hz or greater.

[0032] Optionally, in this embodiment, the lighting device has an update frequency of 25 Hz or greater.

[0033] An update frequency of 25 Hz or greater allows for real-time detection of sunlight incident on the section of the exterior surface, and therefore real-time mimicking of at least one inferred characteristic by the lighting device.

[0034] In an embodiment according to the first aspect of the invention, the sensor device is connected to a photovoltaic system comprising a solar cell, the solar cell being arranged on an upwardly facing outer surface of the vehicle, the sensor device being configured to infer at least one characteristic of light incident on a section of the outer surface of the opaque roof based on determining a parameter indicative of an output of the photovoltaic system.

[0035] An example of an upwardly facing exterior surface is the exterior surface of an opaque roof. As another example, an upwardly facing exterior surface is the hood / bonnet of a vehicle. As another example, an upwardly facing exterior surface is the trunk / luggage compartment of a vehicle.

[0036] Photovoltaic cells, or solar cells, convert light, e.g., sunlight or artificial light, incident on their upward-facing outer surface into electricity. When light is incident on a solar cell, a voltage and current are output from the solar cell. When the intensity of light incident on the solar cell increases, the current output of the solar cell increases. The total power P generated by a solar cell can be calculated as the product of the voltage output V and the current output I, i.e., P=V*I. For example, a photovoltaic system comprising solar cells is used to generate electricity to power certain systems of a vehicle, e.g., to charge a battery of the vehicle, e.g., a high-voltage battery of the vehicle. The output of the photovoltaic system depends on the output (i.e., voltage and current) of the solar cells comprised by the photovoltaic system. In some examples, the photovoltaic system comprises multiple solar cells connected in series and / or in parallel. Thus, the output of the photovoltaic system is the combined output of the multiple solar cells.

[0037] The sensor device in this embodiment is connected to the photovoltaic system. For example, the sensor device is directly connected to a solar cell. If the photovoltaic system comprises multiple solar cells, the sensor device is connected to, for example, each solar cell of the multiple solar cells. In another example, the sensor device is connected to the output of the photovoltaic system.

[0038] The sensor device is configured to determine a parameter indicative of an output of the photovoltaic system. The sensor device receives information about the output of the photovoltaic system through a connection to the photovoltaic system. For example, the sensor device receives information about the voltage output and current output of each solar cell of the photovoltaic system. In this example, the determined parameter is the voltage output and / or the current output of each solar cell of the photovoltaic system.

[0039] The sensor device is configured to infer at least one characteristic of the light incident on the section of the outer surface based on the determination of the parameter indicative of the output of the photovoltaic system. A relationship, for example a linear relationship, exists between the output of the photovoltaic system and the intensity of the light incident on the photovoltaic cell of the photovoltaic system. For example, the intensity of the light incident on the photovoltaic cell is expressed in lux, i.e. lumens per square meter.

[0040] Thus, the photovoltaic system comprising the solar cell is reused in this embodiment as part of a sensor device for inferring at least one characteristic of the light incident on a section of the outer surface of the opaque roof, thereby reducing the complexity of the sensor device and avoiding the installation of additional hardware.

[0041] Optionally, in this embodiment, the solar cells of the photovoltaic system are disposed within a section of the outer surface of the opaque roof. Determining the parameters indicative of the output of the photovoltaic system includes measuring the power and / or current and / or voltage generated by the solar cells.

[0042] Therefore, a parameter indicative of the output of the photovoltaic system can be directly used to infer at least one characteristic of the light incident on the section of the outer surface.

[0043] Optionally, in this embodiment, solar cells of the photovoltaic system are positioned outside the section of the outer surface of the opaque roof. Determining the parameter indicative of the output of the photovoltaic system includes measuring the power and / or current and / or voltage generated by the solar cells. The sensor device is configured to infer at least one characteristic of light incident on the section of the outer surface of the opaque roof additionally based on a distance of the solar cells relative to the section of the outer surface of the opaque roof and a speed of the vehicle.

[0044] In this case, since the solar cells of the photovoltaic system are not disposed within the compartments of the outer surface, additional processing is required to infer at least one characteristic of the light incident on the compartments of the outer surface. By disposing the solar cells outside the compartments on the outer surface, hardware costs can be reduced since not every compartment of the outer surface requires a solar cell to be installed in or on it. Additionally, in this embodiment, processing costs are low since the position, shape and size of the outer surface compartments and the position of the solar cells are constant and known. Thus, the distance between the solar cells and each compartment of the outer surface is also known. In this embodiment, the interior lighting system and / or the vehicle comprises a speed sensor and / or a velocity sensor, which is configured to measure the speed and / or speed at which the vehicle is currently traveling, for example, the speed and / or speed is expressed in m / s. Optionally, the speed sensor and / or the speed sensor is configured to determine whether the vehicle is moving forward or backward.

[0045] Based on the distance of the solar cell to the section of the outer surface of the opaque roof and the speed and / or velocity of the vehicle, the sensor device is configured to infer at least one characteristic of light incident on the section of the outer surface. For example, the sensor device may calculate that the determined parameter indicative of the output of the photovoltaic system represents light incident on the section of the outer surface at a time in the future, e.g., 0.1 seconds or 0.5 seconds or 1 second, based on the speed of the vehicle. Thus, the sensor device may buffer the output of the photovoltaic system over time and use the buffered output to infer at least one characteristic of light incident on the section of the outer surface.

[0046] Optionally, in this embodiment, the photovoltaic system comprises a plurality of solar cells forming a string of solar cells. The photovoltaic system further comprises a maximum power point tracker connected to the string of solar cells, the maximum power point tracker configured to convert power between the photovoltaic system and a load. Determining the parameter indicative of the output of the photovoltaic system includes measuring the power and / or current and / or voltage generated by the string of solar cells, the measurements being provided by the maximum power point tracker.

[0047] Maximum Power Point Tracking (MPPT) is used by a maximum power point tracker to optimize the power conversion of a string of solar cells. The MPPT samples the output of the solar cells and / or the output of the solar cell string to determine an operating point for optimizing and / or maximizing the power output of the solar cells and / or the string of solar cells. Thus, the maximum power point tracker receives as input the voltage and current outputs of the solar cells and / or the solar cell string.

[0048] Thus, the input of the MPPT is reused by the sensor device to determine a parameter indicative of the output of the photovoltaic system, thereby reducing hardware costs.

[0049] Optionally, in this embodiment, the opaque roof comprises a plurality of roof sections, the roof sections being arranged in a pattern, each roof section of the opaque roof comprising a corresponding section of the outer surface of the opaque roof and a corresponding section of the inner surface of the opaque roof.

[0050] The solar cells are arranged in the same pattern as the roof sections, such that each roof section's outer surface section comprises at least one solar cell and / or at least one string of solar cells. In an alternative or additional example, multiple solar cells are arranged in solar modules, i.e., solar panels, and the solar modules are arranged in the same pattern as the roof sections.

[0051] Optionally, in this embodiment, the sensor device is configured to infer at least one characteristic of light incident on each section of the outer surface of the opaque roof, and the control device is configured to control each lighting device such that the at least one characteristic of light emitted by the respective lighting device mimics the at least one characteristic of light incident on the respective section of the outer surface of the opaque roof.

[0052] Thus, the sensor device is configured to infer at least one characteristic of the light incident on each section of the outer surface based on the determination of the parameter indicative of the output of the photovoltaic system. For example, the sensor device determines for each solar cell module arranged in the pattern of the roof section a parameter indicative of the output of the solar cell module, e.g., current output and / or voltage output. Since there is a one-to-one relationship between the solar cell module and the section of the outer surface, the solar cell module directly corresponds to the section of the outer surface. Thereby, the processing cost of the sensor device inferring at least one characteristic of the light incident on each section of the outer surface is reduced, since these at least one characteristic can be directly inferred from the output of the solar cell module. Hardware costs are also reduced, since no additional hardware needs to be installed other than the solar cell module.

[0053] Optionally, in this embodiment, the interior lighting system comprises as many sensor devices as there are roof sections, each sensor device configured to infer at least one characteristic of light incident on a respective section of the outer surface of the opaque roof.

[0054] Thereby, the sensor devices are positioned close to the respective sections of the outer surface, i.e. close to the solar cells and / or solar modules for which the sensor devices determine parameters indicative of the output of the solar cells and / or solar modules, thereby reducing the complexity of the sensor devices and the wiring between the solar cells and / or solar modules and the sensor devices.

[0055] Optionally, in this embodiment, the roof sections are arranged in a grid pattern.

[0056] For example, the grid pattern defines a rectangle, in other words, a rectangular area of ​​opaque roof, the rectangle including multiple roof sections.

[0057] In an embodiment according to the first aspect of the invention, the lighting device is integrated into the roof lining of the inner surface of the opaque roof of the vehicle.

[0058] The roof lining of the inner surface of the opaque roof comprises, for example, a woven fabric, for example, polyester or nylon, or, for example, a fabric. The lighting device is, for example, an LED strip, individual LEDs, or a light bulb, or a strip light, or a fluorescent light. In this embodiment, such a lighting device is integrated into the roof lining. For example, the lighting device is disposed on top of the roof lining, i.e., the roof lining is partially covered by the lighting device. In another example, the lighting device is embedded in the roof lining, i.e., the lighting device is part of the roof lining. In yet another example, the lighting device is disposed behind the roof lining, i.e., the roof lining covers the lighting device, and in such an example, the roof lining is at least partially transparent so that the light emitted by the lighting device passes through the roof lining and is visible when looking at the roof lining. In yet another example, the lighting device is integrated into a panel or encasing, which is at least partially transparent, optionally completely transparent, so that the light emitted by the lighting device passes through the panel or encasing and is therefore visible when looking at the panel or encasing. In that case, the panel or housing functions as a roof lining, in other words the lighting device is part of or forms the roof lining of the inner surface of the opaque roof of the vehicle.

[0059] By incorporating a lighting device within the interior surface roof lining, at least one characteristic of the light incident on the section of the exterior surface of the opaque roof can be mimicked with reduced processing load on the control device, and there is a 1:1 or near 1:1 correspondence between the at least one characteristic of the light incident on the section of the exterior surface of the opaque roof and the at least one characteristic of the light emitted from the section of the interior surface of the opaque roof.

[0060] Optionally, in this embodiment, the lighting device is integrated into a section of the inner surface of the opaque roof of the vehicle.

[0061] By integrating the lighting device into the interior surface section, the structure of the interior lighting system is simplified, the processing load of the control device is minimized, and there is a 1:1 or near 1:1 correspondence between the location of the lighting device and the interior surface section from which it emits light. Thus, by integrating the lighting device into the interior surface section, the light incident on the exterior surface section of the opaque roof can be directly mimicked by the lighting device.

[0062] Optionally, in this embodiment, the opaque roof comprises a plurality of roof sections, the roof sections being arranged in a pattern, each roof section of the opaque roof comprising a corresponding section of the outer surface of the opaque roof and a corresponding section of the inner surface of the opaque roof.

[0063] Thus, the inner surface comprises multiple zones, and by emitting light from the inner surface, the accuracy of mimicking at least one characteristic of the light incident on the outer surface of the opaque roof is increased. In other words, by increasing the number of zones on the inner surface, more values ​​representative of the light incident on the opaque roof can be mimicked, i.e., one value per zone on the inner surface.

[0064] Optionally, in this embodiment, the interior lighting system comprises as many lighting devices as there are roof sections, each lighting device configured to emit light from a respective section of the inner surface of the opaque roof.

[0065] Thus, lighting devices are integrated into each section of the inner surface of the vehicle's opaque roof. By increasing the inner resolution, the number of lighting devices is increased and therefore the light incident on the outer surface of the opaque roof is mimicked with increased accuracy. By integrating the lighting devices into the roof sections, the lighting devices become part of or even form the roof lining of the inner surface of the opaque roof.

[0066] Optionally, in this embodiment, the sensor device is configured to infer at least one characteristic of light incident on each section of the outer surface of the opaque roof, and the control device is configured to control each lighting device such that the at least one characteristic of light emitted by the respective lighting device mimics the at least one characteristic of light incident on the respective section of the outer surface of the opaque roof.

[0067] Thereby, since there is a one-to-one or near one-to-one correspondence between the roof sections, the outer surface sections, the inner surface sections and the lighting devices configured to emit light from the inner surface sections of the vehicle's opaque roof, the processing load of the control device for controlling the lighting devices to mimic at least one characteristic of light incident on the outer surface sections of the opaque roof by emitting light from the inner surface sections of the opaque roof is minimized.

[0068] Optionally, in this embodiment, the roof sections are arranged in a grid pattern.

[0069] The grid pattern may for example define a rectangle, in other words a rectangular area of ​​opaque roof, the rectangle comprising a number of roof sections.

[0070] In an embodiment according to the first aspect of the invention, the lighting device comprises a plurality of light sources, for example the light sources being light emitting diodes, and the control device is configured to control the plurality of light sources such that at least one characteristic of the light emitted by the lighting device matches at least one characteristic of the light incident on the section of the outer surface of the opaque roof inferred by the sensor device.

[0071] In some cases, the inner resolution is lower than the outer surface. In such cases, the amount of partitions of the inner surface is less than the amount of partitions of the outer surface. In still other cases, the sensor device is configured to estimate at least one characteristic of the light incident on the partitions of the outer surface at a certain refresh rate, i.e., the sensor device is configured to estimate the at least one characteristic several times per second.

[0072] To accurately mimic the light incident on the exterior surface, the lighting device in this embodiment comprises multiple light sources. For example, the lighting device is an LED strip and the light sources are individual light emitting diodes. The individual light sources are individually addressable, i.e., a control device connected to the lighting device can individually control each light source to emit light with specific characteristics. This embodiment minimizes the amount of components required for the interior lighting system, since a single lighting device can be used to emit light from a relatively large area of ​​the interior surface of the opaque roof.

[0073] When the inner resolution is lower than the outer resolution, the control device is configured to individually control each light source contained within the lighting device such that at least one characteristic of light emitted from the section of the inner surface of the opaque roof mimics at least one characteristic of light incident on the multiple sections of the outer surface of the opaque roof. In other words, the section of the inner surface is virtually divided by the control device into multiple smaller sections that correspond one-to-one or nearly one-to-one with the sections of the outer surface. Thereby, multiple virtual subsets of light sources are created that are associated with and correspond to the multiple smaller sections within the section of the inner surface of the opaque roof.

[0074] If the sensor device is configured to estimate at least one characteristic of the light incident on the section of the outer surface at a certain refresh rate, the sensor device is configured to temporarily buffer the estimated at least one characteristic of the light incident on the section of the outer surface of the opaque roof. Such a buffer thus includes a plurality of estimated characteristics of the light incident on the section of the outer surface over a certain period of time. The location of each individual light source is known, and therefore it is known at what point in time the buffered characteristic of the light incident on the section of the outer surface should be mimicked by the individual light source based on the speed and / or velocity of the vehicle. Thereby, with minimal additional processing, the control device is configured to individually address the individual light sources to accurately mimic the light incident on the outer surface over time. Thereby, the inner resolution is increased without increasing the number of sections of the inner surface of the opaque roof.

[0075] Optionally, in this embodiment, the opaque roof comprises a plurality of roof sections, the roof sections being arranged in a pattern, each roof section of the opaque roof comprising a corresponding section of the outer surface of the opaque roof and a corresponding section of the inner surface of the opaque roof, and the interior lighting system comprises a number of lighting devices equal to the number of roof sections, each lighting device configured to emit light from a respective section of the inner surface of the opaque roof.

[0076] Thus, each lighting device emits light from just one section of the inner surface of the opaque roof. The section resolution is additionally defined by the lighting device comprising multiple light sources. In other words, by increasing the number of light sources, the section resolution is increased. By increasing the section resolution, the light incident on the outer surface of the opaque roof is more accurately mimicked by emitting light from sections of the inner surface, within which each light source may emit light with different characteristics, since the light sources are individually addressable and controllable by the control device.

[0077] Optionally, in this embodiment, the sensor device is configured to infer at least one characteristic of light incident on each section of the outer surface of the opaque roof, and the control device is configured to control each lighting device such that the at least one characteristic of light emitted by the respective lighting device mimics the at least one characteristic of light incident on the respective section of the outer surface of the opaque roof.

[0078] Thus, the ability of the control device to mimic light incident on the exterior surface of the opaque roof is enhanced because the zone resolution allows differentiated characteristics to be mimicked within a single zone of the interior surface. Such differentiated characteristics allow for a finer imitation of light incident on the exterior surface of the opaque roof.

[0079] Optionally, in this embodiment, the roof sections are arranged in a grid pattern.

[0080] Optionally, in this embodiment, the lighting device is integrated into the roof lining of the inner surface of the opaque roof of the vehicle.The lighting device is integrated into a section of the inner surface of the opaque roof of the vehicle.

[0081] According to a first aspect of the invention, the invention further relates to a vehicle comprising an interior lighting system, the interior lighting system being a lighting system according to any one of the embodiments of the interior lighting system according to the first aspect of the invention.

[0082] A vehicle includes an opaque roof, and by incorporating an interior lighting system into the vehicle, light incident on the outer surface of the opaque roof is simulated by emitting light from the inner surface of the opaque roof, thereby achieving the effect of the roof being transparent.

[0083] According to a first aspect of the invention, the invention further relates to a computer implemented method for controlling an interior lighting system of a vehicle, the vehicle comprising an opaque roof, the opaque roof comprising an outer surface exposed to an environment surrounding the vehicle and an inner surface exposed to an interior volume of the vehicle, a division of the outer surface of the opaque roof of the vehicle being associated with a division of the inner surface of the opaque roof of the vehicle, the method comprising: receiving from the sensor device at least one characteristic of light incident on a section of an exterior surface of an opaque roof of the vehicle, the characteristic being inferred by the sensor device; controlling a lighting device of an interior lighting system of the vehicle such that at least one characteristic of light emitted from the section of the inner surface mimics at least one characteristic of light incident on the section of the outer surface of the opaque roof as inferred by the sensor device, the lighting device being configured to emit light from the section of the inner surface of the opaque roof of the vehicle into an interior volume of the vehicle; Includes.

[0084] In an embodiment according to the first aspect of the invention, the opaque roof comprises a plurality of roof sections, the roof sections being arranged in a pattern. Each roof section of the opaque roof comprises a corresponding section of an outer surface of the opaque roof and a corresponding section of an inner surface of the opaque roof. The interior lighting system comprises a number of lighting devices equal to the number of roof sections, each lighting device configured to emit light from a respective section of the inner surface of the opaque roof. The sensor device is configured to infer at least one characteristic of the light incident on each section of the outer surface of the opaque roof.

[0085] In this embodiment, the method further includes controlling each lighting device such that at least one characteristic of light emitted by the respective lighting device mimics at least one characteristic of light incident on the respective section of the exterior surface of the opaque roof.

[0086] In an embodiment according to the first aspect of the present invention, in the step of receiving from the sensor device at least one characteristic of light incident on a section of the outer surface of the opaque roof of the vehicle inferred by the sensor device, the at least one characteristic of light incident on the section of the outer surface of the opaque roof of the vehicle is received at an update frequency of 25 Hz or greater.

[0087] In an embodiment according to the first aspect of the invention, the lighting device comprises a plurality of light sources, for example the light sources being light emitting diodes, in this embodiment the method further comprises controlling the plurality of light sources such that at least one characteristic of the light emitted by the lighting device matches at least one characteristic of the light incident on the section of the outer surface of the opaque roof inferred by the sensor device.

[0088] According to the first aspect of the invention, the invention further relates to a computer program comprising instructions which, when said computer program is executed by a computing device, cause said computing device to carry out the steps of the method according to the first aspect of the invention.

[0089] In a second aspect, the invention intends to combine the advantages of a transparent roof with the benefits of an opaque roof. To that end, a vehicle having an opaque roof and an interior volume for accommodating passengers and a lighting system for illuminating at least a part of the interior volume is characterized in that the vehicle comprises a sensor for detecting the amount of light incident on the roof, and the signal of the sensor is equipped to adjust the illuminance level of the lighting system.

[0090] By having a lighting system with variable intensity and a sensor that senses the light level outside the vehicle, the lighting level inside the vehicle can correspond to the light level outside the vehicle. This means that when driving in the sun, the lighting level inside the vehicle is also high, but when entering a tunnel, for example, the lighting level decreases. Also, when driving on a road with (overhanging) trees, the lighting level is adjusted accordingly.

[0091] It should be noted that in its simplest form the sensor is, for example, a light sensor located behind the windshield.

[0092] In an embodiment according to the second aspect of the invention, the roof exhibits a plurality of photovoltaic cells, the cells being serially connected to a plurality of maximum power point trackers (MPPTs), the MPPTs having a sensor output that outputs a signal that is a function of the illumination of the PV cells connected to the MPPT.

[0093] Recently, vehicles have been introduced with solar cells integrated into the roof. One example is the Lightyear One, available from Atlas Technologies BV of Helmond, The Netherlands. As will be apparent to those skilled in the art, such roofs are not transparent, but may maintain a slight transparency. Groups of solar cells on such roofs are typically connected in series to form strings. To optimize the power obtained from such strings, a maximum power point tracker (MPPT) is connected to the string to represent a load with an impedance at which the string delivers optimal power. This is necessary because this impedance is a function of the illumination of the cells in the string. At little cost, the MPPT can be equipped with an output that outputs a signal corresponding to the illumination level of the string, and therefore the outside light level.

[0094] In another embodiment according to the second aspect of the invention, the interior lighting system comprises several light groups, the groups being equipped to output spatially different light levels in response to spatially different sensor levels.

[0095] In this embodiment, the lighting system is divided into several groups, each group connected to a corresponding sensor. This makes it possible to vary the intensity levels forming a pattern corresponding to that of the lighting illuminating the roof, for example. As an example, the shadows of tree branches are imitated by an interior lighting system on the roof inside the vehicle.

[0096] In yet another embodiment according to the second aspect of the invention, the sensor is the output of an MPPT and the lighting system comprises an illuminated dial and / or indicator and / or screen, the intensity of illumination of at least a part of the dial and / or indicator and / or screen being a function of the sensor value.

[0097] Most vehicles have illuminated dials, indicators and screens for interaction between the vehicle and the driver, including navigation systems, speedometer indicators, flashing indicators, etc. In sunlight (when the driver is looking at a brightly lit external environment), the illumination level of such dials, indicators and screens is preferably much higher than when driving in the dark.

[0098] In yet another embodiment according to the second aspect of the invention, the vehicle further comprises a manually adjustable override for overriding the sensor.

[0099] A manual override can increase or decrease illumination, one example being increasing the lights when parked in the dark, for example when reading a map.

[0100] It should be noted that such a manual override may be a manually adjustable level or a binary override providing either a first level and / or a second level.

[0101] In yet another embodiment of the second aspect of the invention, the lighting system is equipped to vary not only the intensity but also the color.

[0102] Preferably, the lighting system is equipped not only to vary the intensity level but also to vary the color, for example the corresponding color temperature of the lighting can be changed from a high of 10000K at midday to less than 3000K when the sun is low above the horizon, and the greenish color of a road with overhanging tree branches can be simulated.

[0103] Note that solar cells connected to MPPTs are in most cases not sensitive to the color of (external) light, but other sensors may be. Also, multi-junction solar cells, basically two stacked layers of solar cells, can distinguish colors if each stacked layer has its own (set of) MPPT.

[0104] In yet another embodiment according to the second aspect of the invention, the lighting system comprises photoconductive fibres for transporting light from one or more light sources to a portion of the interior roof.

[0105] In another embodiment according to the second aspect of the invention, the lighting system comprises a programmable controller having as inputs output signals of the one or more sensors and having as outputs one or more signals for driving the lighting system.

[0106] Note that both input and output signals may be multiplexed or may be addressable values ​​if the sensor and programmable controller are connected, for example, by a CAN bus. Similarly, the programmable controller and lighting system may be connected via a CAN bus.

[0107] According to a second aspect of the invention, a programmable controller is programmed with software and protection is sought against the software for programming the programmable controller.

[0108] The invention will be described below with reference to the figures, which serve as examples for illustrating the invention and are not to be construed as limiting the scope of the claims. In the different figures, similar features are indicated by similar reference numbers. [Brief description of the drawings]

[0109] [Figure 1] FIG. 2 shows a schematic diagram of a string of PV cells with MPPT according to a second embodiment of the present invention. [Diagram 2] FIG. 2 shows a schematic diagram of a lighting system according to a second embodiment of the present invention; [Diagram 3] FIG. 1 shows a schematic diagram of a lighting system according to an embodiment of the first aspect of the present invention; [Figure 4] FIG. 1 shows a schematic diagram of a lighting system according to an embodiment of the first aspect of the present invention; [Diagram 5] FIG. 1 shows a schematic diagram of a lighting system according to an embodiment of the first aspect of the present invention; [Figure 6] FIG. 1 shows a schematic diagram of a lighting system according to an embodiment of the first aspect of the present invention; [Figure 7] FIG. 1 shows a schematic diagram of a lighting system according to an embodiment of the first aspect of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0110] FIG. 1 illustrates diagrammatically a string of solar cells, also known as photovoltaic cells or PV cells, with MPPT according to a second embodiment of the present invention.

[0111] Each cell 100-1 to 100-n is interconnected to form a string that, when illuminated, has an open source voltage Uopen≈0.7V and a short circuit current Ishort that is a function of the illuminance and surface area. Preferably, the maximum total open circuit voltage of the string is less than a safe voltage, i.e., 60V. The aforementioned Uopen is a typical value for monocrystalline silicon solar cells; other values ​​may occur when using other materials, such as polycrystalline silicon, GaAs, perovskite, organic solar cells, etc.

[0112] The maximum power can be "harvested" at an impedance (resistive load) that depends on the illumination. Maximum power point trackers 102 or MPPTs are known per se to those skilled in the art and are described, for example, in Toyota's European patent application EP2933699A1, "CONTROL DEVICE FOR IN-VEHICLE SOLAR CELL". The MPPT has two inputs 104 and 106 connected to the string and an output 108 connected to the power bus 112.

[0113] Because the MPPT must change the load impedance according to the illumination of the solar cells, a small addition to the electronics allows the MPPT to act as a sensor output 110 for the amount of light falling on the string of solar cells.

[0114] Note that in many cases the MPPT will already have such a signal built in, for example for diagnostic purposes. The signal may be available as an analog signal, or on a digital bus 112 such as a CAN bus where each MPPT has a unique address. Other types of (multiplexed) buses are also possible.

[0115] FIG. 2 shows diagrammatically a lighting system according to a second embodiment of the invention.

[0116] FIG. 2 shows diagrammatically several strings 202 of PV cells each connected to an MPPT 204, which is connected to a programmable controller 208 (also known as a microprocessor) via a bus, such as a CAN bus 206. The CAN bus is a bus known to those skilled in the art as a communication bus widely used in the automotive industry. A manual override switch 210 is connected to the controller 208, the switch providing an override signal to the controller. The manual override signal preferably has three states, on, auto, and off, corresponding to the states "lighting on", "lighting controlled by sensor", and "lighting off". However, other combinations are possible, and the level of intensity of the on level can be a different (predetermined) level from the maximum illumination achievable in the "auto" state.

[0117] The controller outputs one or more signals to one or more drivers 212-1...212-j, which are connected to corresponding light sources 214-1...214-j, such as LEDs. It should be noted that several light sources can be connected in series and / or in parallel to one driver. The light sources then illuminate the interior of the vehicle. Similarly, the programmable controller is connected to the driver 216 of the intensity control of the dials and / or indicators and / or screens 218. Those skilled in the art can think of many more variations. Since the controller is a programmable controller, various behaviors can be programmed into the controller by loading appropriate software into the controller.

[0118] Note that the controller, driver, and light source can change the hue either by manual override or by a sensor value. This does not have to be the same sensor that controls the intensity (e.g., the output of the MPPT), but as an example could be a forward looking color discrimination sensor 220 mounted near the windshield. The sensor could have a separate input on the controller or be connected to the CAN bus 206.

[0119] Also, note that the driver may be connected to the CAN bus 206 or a separate CAN bus.

[0120] The driver then provides power (voltage, current) for light-emitting components such as LEDs. The light is distributed over the (inside of) the roof by having light sources (LEDs) distributed over the roof, or by transporting the light from the LEDs to different ports of the roof, for example by glass fibers. In the latter case, the whole roof, being the woven fibers that transport the light, can be lit evenly.

[0121] Software updates for the programmable controller can be performed via an update bus or via Over-the-Air (OTA) transmission, both methods being known to those skilled in the art.

[0122] FIG. 3 shows diagrammatically a lighting system 301 for a vehicle according to an embodiment of the first aspect of the invention.

[0123] The vehicle comprises an opaque roof 302. The opaque roof 302 comprises an exterior surface 303 exposed to the environment surrounding the vehicle and an interior surface 304 exposed to the interior volume of the vehicle.

[0124] The interior lighting system comprises a sensor device 305 configured to infer at least one characteristic of light incident on a section 306 of an outer surface 303 of an opaque roof 302 of the vehicle.

[0125] The interior lighting system further comprises a lighting device 307 configured to emit light from a section 308 of the inner surface 304 of the opaque roof 302 of the vehicle into the interior volume of the vehicle.

[0126] The interior lighting system further includes a control device 309 connected to the sensor device 305 and the lighting device 307, and the control device 309 is configured to control the lighting device 307 such that at least one characteristic of light emitted from the section 308 of the inner surface 304 of the opaque roof 302 mimics at least one characteristic of light incident on the section 306 of the outer surface 303 of the opaque roof 302 as inferred by the sensor device 305.

[0127] A section 306 of an outer surface 303 of the opaque roof 302 of the vehicle is associated with a section 308 of an inner surface 304 of the opaque roof 302 of the vehicle.

[0128] The opaque roof 302 comprises a plurality of roof sections 310, which are arranged in a pattern. In the figure, one such roof section 310 is shown. Each roof section 310 of the opaque roof 302 comprises a corresponding section 306 of the outer surface 303 of the opaque roof 302 and a corresponding section 308 of the inner surface 304 of the opaque roof 302. The opaque roof 302 shown in FIG. 3 comprises a total of 24 roof sections, but only one is explicitly shown. The outer surface 303 of the opaque roof 302 shown in FIG. 3 comprises a total of 24 sections 306. The inner surface 304 of the opaque roof 302 shown in FIG. 3 comprises a total of 24 sections 308. Thus, each roof section 310 comprises one section 306 of the outer surface 303 and one section 308 of the inner surface 304.

[0129] The sensor device 305 is configured to infer at least one characteristic of the light incident on each section 306 of the outer surface 303 of the opaque roof 302 .

[0130] The control device 309 is configured to control each lighting device 307 such that at least one characteristic of the light emitted by the respective lighting device 307 mimics at least one characteristic of the light incident on the respective section 306 of the outer surface 303 of the opaque roof 302. The interior lighting system 301 shown in Figure 3 comprises a total of 24 lighting devices 307.

[0131] The interior lighting system 301 comprises a number of sensor devices 305 equal to the number of roof sections, each sensor device 305 configured to infer at least one characteristic of light incident on a respective section 306 of the outer surface 303 of the opaque roof 302.

[0132] The roof sections 310 are arranged in a grid pattern. The roof sections 310 are arranged in a 4 by 6 grid pattern.

[0133] In the perspective of Figure 3, the outer surface 303 and the inner surface 304 are seen from a perspective, i.e. from outside the vehicle or from inside the vehicle. Therefore, to see the figure correctly, the outer surface 303 must be imagined as being placed above the inner surface 304. Section 306 of the outer surface 303 is thereby associated with section 308 of the inner surface 304.

[0134] FIG. 4 shows diagrammatically a lighting system 301 according to an embodiment of the first aspect of the invention.

[0135] The embodiment shown in FIG. 4 is identical to the embodiment shown in FIG. 3, except for the following modifications.

[0136] The opaque roof 302 comprises a plurality of roof sections 310, which are arranged in a pattern. In the figure, one such roof section 310 is shown. Each roof section 310 of the opaque roof 302 comprises a corresponding section 306 of the outer surface 303 of the opaque roof 302 and a plurality of corresponding roof sections 308 of the inner surface 304 of the opaque roof 302. The opaque roof 302 shown in FIG. 4 comprises a total of four roof sections, but only one is explicitly shown. The outer surface 303 of the opaque roof 302 shown in FIG. 4 comprises a total of four sections 306. The inner surface 304 of the opaque roof 302 shown in FIG. 4 comprises a total of 24 sections 308. Thus, each roof section 310 comprises one section 306 of the outer surface 303 and six sections 308 of the inner surface 304.

[0137] Thus, the inner resolution is higher than the outer resolution. The sensor device 305 is configured to temporarily buffer at least one inferred characteristic of the light incident on the section 306 of the outer surface 303 of the opaque roof 302. Such a buffer thus includes a plurality of inferred characteristics of the light incident on the section 306 of the outer surface 303 over a certain period of time. The sensor device 305 is further configured to control the lighting device 307 such that the at least one characteristic of the light emitted from the section 308 of the inner surface 304 of the opaque roof 302 mimics the at least one characteristic of the light incident on the section 306 of the outer surface 303 of the opaque roof 302 inferred by the sensor device 305. Such control is performed by using the buffered inferred characteristic of the light incident on the section 306 of the outer surface 303 over a certain period of time.

[0138] FIG. 5 shows diagrammatically a lighting system 301 according to an embodiment of the first aspect of the invention.

[0139] The embodiment shown in FIG. 5 is identical to the embodiment shown in FIG. 4, except for the following modifications.

[0140] The opaque roof 302 comprises a plurality of roof sections 310, which are arranged in a pattern. In the figure, one such roof section 310 is shown. Each roof section 310 of the opaque roof 302 comprises a corresponding section 306 of the outer surface 303 of the opaque roof 302 and a corresponding roof section 308 of the inner surface 304 of the opaque roof 302. The opaque roof 302 shown in FIG. 5 comprises a total of three roof sections, but only one is explicitly shown. The outer surface 303 of the opaque roof 302 shown in FIG. 5 comprises a total of nine sections 306, of which three sections 306a, 306b, 306c are shown. The inner surface 304 of the opaque roof 302 shown in FIG. 5 comprises a total of three sections 308. Thus, each roof section 310 comprises three sections 306 of the outer surface 303 and one section 308 of the inner surface 304.

[0141] The sensor device 305 is disposed on the outside of the opaque roof 302. The sensor device 305 is configured to infer at least one characteristic of light incident on the sections 306a, 306b, and 306c of the outer surface 303 of the vehicle's opaque roof 302. Thus, the sensor device 305 is configured to temporarily buffer the inferred at least one characteristic of light incident on the sections 306a, 306b, and 306c of the outer surface 303 of the opaque roof 302. Thus, such a buffer includes multiple inferred characteristics of light incident on the sections 306a, 306b, and 306c of the outer surface 303 over a certain period of time. The control device 305 is further configured to control the lighting device 307 such that at least one characteristic of light emitted from the section 308 of the inner surface 304 of the opaque roof 302 mimics at least one characteristic of light incident on the sections 306a, 306b, and 306c of the outer surface 303 of the opaque roof 302 as inferred by the sensor device 305. Such control is performed by using buffered inferred characteristics of light incident on the sections 306a, 306b, and 306c of the outer surface 303 over a particular period of time.

[0142] The lighting device 307 comprises a plurality of light sources 501, of which four light sources 501a, 501b, 501c, 501d are shown, the lighting devices being LED strips and the light sources being light emitting diodes. The lighting devices are arranged in an "S" pattern within the section 308 of the inner surface 304. The control device 309 is configured to control the plurality of light sources 501 such that at least one characteristic of the light emitted by the lighting device 307 matches at least one characteristic of the light incident on the section 306 of the outer surface of the opaque roof as inferred by the sensor device 305.

[0143] In particular, in this embodiment, the temporarily buffered at least one characteristic is used by the control device 309 to individually control the light sources 501a, 501b, 501c, 501d such that the at least one characteristic of the light emitted by the lighting device 307 matches the at least one characteristic of the light incident on the sections 306a, 306b, and 306c of the outer surface of the opaque roof inferred by the sensor device 305. In particular, the at least one characteristic of the light incident on the section 306c of the outer surface 303 is used by the control device 309 at a particular time to control the light emitted by the light sources 501a and 501b, since these light sources 501a and 501b are located in the corresponding section 308 of the inner surface 304. Additionally, these light sources 501a and 501b are located in a virtual section (not shown) corresponding to the section 306c of the outer surface 303. Similarly, these light sources 501a and 501b are located within corresponding sections 308 of the inner surface 304, so that at least one characteristic of the light incident on section 306c of the outer surface 303 is used by the control device 309 at a time later than that particular time to control the light emitted by light sources 501c and 501d. Additionally, these light sources 501a and 501b are located within a virtual section (not shown) that corresponds to section 306b of the outer surface 303. This assumes that the vehicle is traveling forward at a speed higher than 0 and that section 306c of the outer surface 303 is closer to the front of the vehicle than section 306a of the outer surface 303.

[0144] The sensor device 305 is configured to estimate at least one characteristic of light incident on a section 306 of the outer surface 303 of the vehicle's opaque roof 302 at an update frequency of 25 Hz or greater, so as to achieve a real-time effect that mimics at least one characteristic of light incident on the outer surface 303.

[0145] FIG. 6 shows diagrammatically a lighting system 301 according to an embodiment of the first aspect of the invention.

[0146] The embodiment shown in FIG. 6 is identical to the embodiment shown in FIG. 1, except for the following modifications.

[0147] The sensor device 305 is connected to a photovoltaic system 601 comprising a solar cell 602, the solar cell 602 of the photovoltaic system 601 being arranged in a section 306 of the outer surface 303 of the opaque roof 302. Thus, a parameter indicative of an output of the photovoltaic system is directly usable to infer at least one characteristic of the light incident on the section 306 of the outer surface 303. The sensor device 305 is configured to infer at least one characteristic of the light incident on the section 306 of the outer surface 303 of the opaque roof 302 based on a determination of a parameter indicative of an output of the photovoltaic system 601. The determination of the parameter indicative of an output of the photovoltaic system 601 comprises a measurement of the power and / or the current and / or the voltage generated by the solar cell 602.

[0148] The photovoltaic system 601 comprises a plurality of solar cells 602 forming a string of solar cells 603. The photovoltaic system 601 further comprises a maximum power point tracker 604 connected to the string of solar cells 603, the maximum power point tracker 604 configured to convert power between the photovoltaic system 601 and a load (not shown). Determining a parameter indicative of the output of the photovoltaic system 601 includes measuring the power and / or current and / or voltage generated by the string of solar cells 603, which measurements are provided by the maximum power point tracker 604.

[0149] Thus, the input of the maximum power point tracker 604 is reused by the sensor device 305 to determine a parameter indicative of the output of the photovoltaic system 601 .

[0150] FIG. 7 shows diagrammatically a lighting system 301 according to an embodiment of the first aspect of the invention.

[0151] The embodiment shown in FIG. 7 is identical to the embodiment shown in FIG. 6, except for the following modifications.

[0152] The solar cells 602 of the photovoltaic system 601 are positioned outside the section 306 on the outer surface 303 of the opaque roof 302. The solar cells are positioned on an upward facing outer surface 701 of the vehicle, for example on the hood / bonnet of the vehicle. Determining the parameters indicative of the output of the photovoltaic system 601 includes measuring the power and / or current and / or voltage generated by the solar cells 602.

[0153] The sensor device 305 is configured to infer at least one characteristic of light incident on the section 306 of the outer surface 303 of the opaque roof 302 additionally based on the distance d of the solar cell 602 to the section 306 of the outer surface 303 of the opaque roof 302 and the speed of the vehicle.

[0154] Based on the distance d of the solar cell to the section 306 of the outer surface of the opaque roof and the speed and / or velocity of the vehicle, the sensor device 305 is configured to infer at least one characteristic of the light incident on the section 306 of the outer surface 303. For example, the sensor device 305 may calculate that the determined parameter indicative of the output of the photovoltaic system 601, e.g., the output of the solar cell 602, based on the speed of the vehicle, represents the light incident on the section 306 of the outer surface 303 at a future time, e.g., 0.1 seconds or 0.5 seconds or 1 second in the future. Thus, the sensor device 305 may buffer the output of the photovoltaic system 601 over time and use said buffered output to infer at least one characteristic of the light incident on the section 306 of the outer surface 303.

[0155] The invention according to this disclosure is also described in the following sections.

[0156] 1. A vehicle having an opaque roof and an interior volume for accommodating passengers and a lighting system for illuminating at least a part of the interior volume, characterized in that the vehicle is equipped with a sensor for detecting the amount of light incident on the roof, the signal of the sensor being equipped to adjust the illumination level of the lighting system.

[0157] 2. A vehicle according to item 1, the roof of which exhibits a plurality of photovoltaic cells (100-1...100-n), the cells being serially connected to form a string (202) and connected to a plurality of MPPTs (102, 204), the MPPT having a sensor output (110), the sensor output outputting a signal that is a function of the illumination of the PV cells connected to the MPPT.

[0158] 3. A vehicle according to item 1 or item 2, comprising several lighting groups, the groups being equipped to output spatially different lighting levels in response to spatially different sensor levels.

[0159] 4. A vehicle according to any one of clauses 1 to 3, wherein the sensor is the output of an MPPT (110) and the lighting system comprises an illuminated dial and / or indicator and / or screen, and the intensity of illumination of at least a part of the dial and / or indicator and / or screen is a function of the sensor value.

[0160] 5. The vehicle according to any one of clauses 1 to 4, wherein the vehicle further comprises a manually adjustable override (210) for overriding the sensor.

[0161] 6. A vehicle according to any one of paragraphs 1 to 5, wherein the lighting system is equipped to vary not only the intensity but also the color.

[0162] 7. A vehicle according to any one of clauses 1 to 6, wherein the lighting system comprises a software programmable controller (208), the software programmable controller having as inputs output signals of one or more sensors and having as outputs one or more signals for driving the lighting system.

[0163] 8. Software code for programming the programmable controller of clause 7.

[0164] 9. A lighting system for a vehicle according to any of paragraphs 1 to 8, wherein the lighting system comprises photoconductive fibers that transport light from a light source to a portion of the interior roof.

[0165] Where necessary, this document will describe detailed embodiments of the present invention. However, it must be understood that the disclosed embodiments serve only as examples, and the present invention may be embodied in other forms. Therefore, the specific structural aspects disclosed herein should not be considered as limiting to the present invention, but merely as a basis for the claims and for enabling the present invention to be implemented by an average person skilled in the art. Furthermore, various terms used in the description should not be interpreted as limiting, but rather as a comprehensive description of the present invention. As used herein, the word "a" means one or more, unless otherwise specified. The phrase "plurality" means two or more. The words "comprise" and "have" do not exclude the presence of more elements. Reference numerical values ​​in the claims should not be interpreted as limiting the present invention. A particular embodiment does not necessarily achieve all of the objects described. The mere fact that certain technical measures are specified in different dependent claims still allows the possibility that a combination of these technical measures may be advantageously applied. [Explanation of symbols]

[0166] 100-1~100-n batteries, photovoltaic batteries 102 Maximum Power Point Tracker, MPPT 104 Input 106 Input 108 Output 110 Sensor Output 112 Power bus, digital bus 202 String 204 MPPT 206 CAN bus 208 Programmable controller, controller 210 Manual override switch 212-1...212-j driver 214-1...214-j Light source 216 Driver 218 Dials and / or indicators and / or screens 220 Forward monitoring color discrimination sensor 301 Lighting systems, interior lighting systems 302 Opaque Roof 303 Outer surface 304 Inner surface 305 Sensor Device 306 Plot Section 306a Section 306b Plot 306c 307 Lighting Devices Section 308 309 Control Device 310 Roof Section 501 Light source 501a light source 501b light source 501c light source 501d light source 601 Photovoltaic Systems 602 Solar Cells 603 String 604 Maximum Power Point Tracker 701 Outer surface

Claims

1. An interior lighting system (301) for a vehicle, the vehicle comprising an opaque roof (302), the opaque roof having an exterior surface (303) exposed to an environment surrounding the vehicle and an interior surface (304) exposed to an interior volume of the vehicle, the interior lighting system comprising: a sensor device (305) configured to infer at least one characteristic of light incident on a section (306) of the outer surface (303) of the opaque roof (302) of the vehicle; a lighting device (307) configured to emit light from a section (308) of the inner surface (304) of the opaque roof (302) of the vehicle into the interior volume of the vehicle; a control device (309) connected to the sensor device (305) and the lighting device (307), the control device (309) configured to control the lighting device (307) such that at least one characteristic of light emitted from the section (308) of the inner surface (304) of the opaque roof (302) mimics at least one characteristic of light incident on the section (306) of the outer surface (303) of the opaque roof (302) as inferred by the sensor device (305); Equipped with the section (306) of the outer surface (303) of the opaque roof (302) of the vehicle is associated with the section (308) of the inner surface (304) of the opaque roof (302) of the vehicle; An interior lighting system (301) for a vehicle.

2. the opaque roof comprises a plurality of roof sections (310), the roof sections (310) being arranged in a pattern; each roof section (310) of the opaque roof (302) comprises a corresponding section (306) of the outer surface (303) of the opaque roof (302) and a corresponding section (308) of the inner surface (304) of the opaque roof (302); 2. The vehicle interior lighting system (301) according to claim 1.

3. the interior lighting system comprises lighting devices (307) in the same number as the number of roof sections (310), each lighting device (307) configured to emit light from a respective section (308) of the inner surface (304) of the opaque roof (302); 3. An interior lighting system (301) according to claim 2.

4. the sensor device (305) is configured to infer at least one characteristic of light incident on each section (306) of the outer surface (303) of the opaque roof (302); the control device (309) is configured to control each lighting device (307) such that at least one characteristic of the light emitted by the respective lighting device (307) mimics the at least one characteristic of the light incident on the respective section (306) of the outer surface (303) of the opaque roof (302); An interior lighting system (301) according to claim 3.

5. the interior lighting system (301) comprises a number of sensor devices (305) equal to the number of roof sections, each sensor device (305) configured to estimate at least one characteristic of light incident on a respective section (306) of the outer surface (303) of the opaque roof (302); An interior lighting system (301) according to claim 4.

6. 3. The interior lighting system (301) of claim 2, wherein the roof sections are arranged in a grid pattern.

7. the sensor device (305) is configured to estimate the at least one characteristic of the light incident on the section (306) of the outer surface (303) of the opaque roof (302) of the vehicle at an update frequency of 25 Hz or greater; 2. The vehicle interior lighting system (301) according to claim 1.

8. the sensor device (305) is connected to a photovoltaic system (601) comprising a solar cell (602), the solar cell (602) being placed on an upwardly facing outer surface (303, 701) of the vehicle; the sensor device (305) is configured to infer the at least one characteristic of the light incident on the section (306) of the outer surface (303) of the opaque roof (302) based on a determination of a parameter indicative of an output of the photovoltaic system (601); 2. The vehicle interior lighting system (301) according to claim 1.

9. the solar cells (602) of the photovoltaic system (601) are arranged in the sections (306) of the outer surface (303) of the opaque roof (302); - the determination of the parameters indicative of the output of the photovoltaic system (601) comprises measuring the power and / or current and / or voltage generated by the solar cell (602); An interior lighting system (301) according to claim 8.

10. the solar cells (602) of the photovoltaic system (601) are arranged outside the section (306) of the outer surface (303) of the opaque roof (302); - the determination of the parameters indicative of the output of the photovoltaic system (601) comprises measuring the power and / or current and / or voltage generated by the solar cell (602); the sensor device (305) is configured to infer the at least one characteristic of the light incident on the section (306) of the outer surface (303) of the opaque roof (302) additionally based on a distance (d) of the solar cell (602) relative to the section (306) of the outer surface (303) of the opaque roof (302) and on the speed of the vehicle; An interior lighting system (301) according to claim 8.

11. the photovoltaic system (301) comprises a plurality of solar cells (602) forming a string of solar cells (603); the photovoltaic system (601) further comprises a maximum power point tracker (604) connected to the string of solar cells (603), the maximum power point tracker (604) being configured to convert power between the photovoltaic system (601) and a load; the determination of the parameters indicative of the output of the photovoltaic system (601) comprises measurements of the power and / or current and / or voltage generated by the string of solar cells (603), which measurements are provided by the maximum power point tracker (604); An interior lighting system (301) according to claim 8.

12. 2. The interior lighting system (301) of claim 1, wherein the lighting device (307) is integrated into a roof lining of the inner surface (304) of the opaque roof (302) of the vehicle.

13. 13. The interior lighting system (301) of claim 12, wherein the lighting device (307) is integrated into the compartment (308) of the inner surface (304) of the opaque roof (302) of the vehicle.

14. the lighting device (307) comprises a plurality of light sources (501), for example the light sources (501) being light-emitting diodes; the control device (309) is configured to control the plurality of light sources (501) such that at least one characteristic of the light emitted by the lighting device (307) matches at least one characteristic of the light incident on the section (306) of the outer surface of the opaque roof as inferred by the sensor device (305); 2. The vehicle interior lighting system (301) according to claim 1.

15. A vehicle comprising an interior lighting system according to any one of claims 1 to 14.

16. 1. A computer-implemented method for controlling an interior lighting system of a vehicle, the vehicle comprising an opaque roof, the opaque roof comprising an exterior surface exposed to an environment surrounding the vehicle and an interior surface exposed to an interior volume of the vehicle, wherein a section of the exterior surface of the opaque roof of the vehicle corresponds to a section of the interior surface of the opaque roof of the vehicle, the method comprising: - receiving from a sensor device at least one characteristic of light incident on a section of the outer surface of the opaque roof of the vehicle as inferred by the sensor device; controlling a lighting device of the interior lighting system of the vehicle such that at least one characteristic of light emitted from the section of the inner surface mimics the at least one characteristic of light incident on the section of the outer surface of the opaque roof as inferred by the sensor device, the lighting device being configured to emit light from the section of the inner surface of the opaque roof of the vehicle into an interior volume of the vehicle; 11. A computer-implemented method comprising:

17. 20. A computer program comprising instructions that, when executed by a computing device, cause the computing device to perform the steps of the computer-implemented method of claim 16.

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