OF AN AUTONOMOUS DRIVING VEHICLE

FIELD OF THE INVENTION

The invention relates to a system for controlling interior lighting inside a vehicle, said interior lighting comprising a light source.

The invention further relates to a method of controlling interior lighting inside a vehicle, said interior lighting comprising a light source.

The invention also relates to a computer program product en abling a computer system to perform such a method.

BACKGROUND OF THE INVENTION

In the long term, autonomous vehicles are expected to transform the way people travel, because advanced sensing will enable the vehicles to navigate in traffic without any interventions from human operators. This enables people inside the vehicle to be productive, be entertained, or to sleep or relax.

Whereas music is currently by far the most popular form of in-car entertainment for drivers, it is expected that with the advance of autonomous driving, also watching video and playing games will become important activities for drivers. The future car may be a moving entertainment pod whereby the windows provide mixed reality experiences to support manual driving or to indicate landmarks or touristic highlights outside the car, while during autonomous driving, the windows can be turned into immersive high- definition displays. At the same time, users may want to use the time in the car to relax, unwind, meditate, or to take a nap.

For the time being, however, vehicles will be semi-autonomous. For instance, a so-called level 3 autonomous vehicle will provide conditional automation, meaning that the vehicle can take over all driving functions under certain circumstances. For instance, in a non-complex highway environment, all cars are moving in the same direction and there are no complex intersections. Upon leaving the highway, however, the user may still need to take over the control again and switch to from the autonomous driving mode to a manual driving mode. US 2019/0033860 Al discloses a control unit executing a first driving mode in which at least one of acceleration/decel eration and steering of a subject vehicle is automatically controlled and an environment control unit controlling an environment device of the subject vehicle such that an environment of the inside of a vehicle cabin is in a state appropriate for a second driving mode in a case in which the automatic driving control unit ends execution of the first driving mode and transitions to a second driving mode of which a degree of automatic driving is lower than that of the first driving mode.

Acoustic or visual alerts to indicate disengagement of an autopilot (e.g. in planes) are known. For example, US 2019/0004513 Al discloses determining whether or not a future circumstance indicated by acquired future circumstance information is applicable to an event in which continuation of driving assistance is not possible. A limit setting unit sets a limit related to time or distance, e.g. 10 seconds, at which to cancel driving assistance and switch to manual driving. A notifying unit notifies a driver of information prompting cancellation of driving assistance based on the set limit. A wake-up operation (e.g. vibrating the steering wheel or driver’s seat, shaking by a brake operation, operating the airconditioner, and/or turning off video and audio output) may be performed based on the wakefulness of the driver. However, this wake-up operation may not always be enough to increase the wakefulness of the driver sufficiently.

SUMMARY OF THE INVENTION

It is a first object of the invention to provide a system, which is in certain circumstances able to increase the wakefulness of a driver sufficiently when the driver needs to take control of his vehicle.

It is a second object of the invention to provide a method, which can be used in certain circumstances to increase the wakefulness of a driver sufficiently when the driver needs to take control of his vehicle.

In a first aspect of the invention, a system for controlling interior lighting inside a vehicle, said interior lighting comprising a light source, comprises at least one control interface and at least one processor configured to obtain navigation information, determine an estimation of an end time of an autonomous driving mode based on said navigation information, said vehicle switching to a manual driving mode at said end time, determine, based on said estimation of said end time, an energizing light start time ahead of said end time, and control, via said at least one control interface, said light source inside said vehicle to render energizing light starting at said energizing light start time. When alerting a driver that the autonomous driving mode will end by vibrating the steering wheel or driver’s seat, shaking by a brake operation, operating the airconditioner, and/or turning off video and audio output, it is normally possible to wake up the driver, but not to increase the wakefulness of the driver to a desired level. This is important, because the driver needs to be well awake and alert before taking over control of the steering wheel. The above-described system may be used to increase the wakefulness of the driver to a desired level by rendering energizing light which starts sufficiently ahead of the autonomous driving mode end time.

Said energizing light start time preferably starts between 5 and 15 minutes before said estimation of said end time, e.g. 10 minutes before the estimated end time, to increase the wakefulness of the driver to a desired level at the take-over moment. Starting later may make it impossible to increase the wakefulness of the driver to the desired level at the take-over moment. Starting earlier reduces the amount of time the driver has for relaxing or taking a nap.

Said energizing light may comprise wavelengths in the range 447-531 nm, for example. The melanopic sensitivities are highest in this range, e.g. between 0,75 and 1 (1 being the highest) in a range of 463-517 nm and between 0,5 and 1 in the range of 447-531 nm. For instance, the melanopic sensitivity is high when the energizing light has a cyan component (in the range of 490-520 nm). While the energizing light is rendered, an “ambience boost” may be provided in anticipation of the take-over moment, whereby intensive light, sounds, air breeze and/or tactile stimuli (e.g. using massage chairs) are provided to further energize the driver.

Said navigation information is typically based on centrally collected traffic information, e.g. information about traffic jams, traffic accidents, and/or adverse weather conditions later on the route. Said navigation information may specify the estimation of an end time of an autonomous driving mode or may comprise information which enables this estimation to be calculated. As an example of the former, an in-vehicle ambience control system may receive information with regards to an upcoming take-over moment from a navigation system or app. In addition to the received timing, the in-vehicle ambience control system may receive further information about the route complexity and traffic conditions which are expected after the take-over moment.

Said at least one processor may be configured to control said light source to stop rendering ambience light in said vehicle before or upon controlling said light source to render said energizing light. Ambience lighting (also referred to as ambient lighting) typically has a low intensity and is typically colored light. While a reading light is a functional light, ambience lighting is typically used to provide a pleasing aesthetic effect, e.g. static or dynamic light effects with one color or with multiple colors, and to improve the driving experience.

Said at least one processor may be configured to control said light source to render a gradual transition from said ambience light to said energizing light. Said gradual transition preferably has a duration of one minute or less. The conditions to energize the driver are typically different than the optimal conditions to view the traffic and drive the car. A gradual transition between these two modes is more pleasant for the driver if he is not taking a nap.

Said at least one processor may be configured to select said light source from a plurality of light sources based on a driver location (e.g. a location of the driver’s head) and locations of said plurality of light sources. The light source may further be selected based on an orientation of the driver’s head. Since only the driver needs to have a desired level of wakefulness, the passengers may appreciate it if only a light source near the driver is used to render the energizing light. However, in this case, if the driver does not respond, the passengers may also be alerted and/or energized with energizing light. If the system is not statically configured or arranged to control an appropriate light source from the plurality of light sources to render the energizing light, e.g. if the system is not embedded in the car, the system may be able to select the appropriate light source dynamically.

Said at least one processor may be configured to determine said energizing light start time and/or an intensity at which said energizing light is going to be rendered based on an ambient light level, a scheduled activity at a driving destination, a remaining autonomous driving time and/or an alertness level of said driver. As a first example, a lower intensity of the energizing light may be used if there is enough daylight. As a second example, a higher intensity of the energizing light may be used if the driver has a meeting when he arrives at his destination. As a third example, a lower intensity of the energizing light may be used if the remaining autonomous driving time is significant, to allow the driver to relax, unwind, meditate or take a nap again.

Said at least one processor may be configured to render said energizing light as either white light or non-white light in dependence on said ambient light level. For example, in the time around sunrise and sunset, the energizing light may be rendered as white light, as this is more pleasant for the driver and the passengers, while at night, the energizing light may be rendered as cyan light to ensure that the driver can still see the environment outside the vehicle optimally.

Said at least one processor may be configured to determine a reaction of a driver to said energizing light and increase an intensity of said energizing light if said driver’s alertness has not increased or has not increased above a threshold in reaction to said energizing light and/or reduce said energizing light upon determining that a driver’s alertness has increased above a desired amount and/or said driver has taken control over said vehicle. This may be used to ensure that the driver has a desired level of wakefulness at the take-over moment while preventing that too much energizing light is rendered unnecessarily.

Said at least one processor may be configured to control said light source to gradually reduce said energizing light upon determining that said driver’s alertness has increased above said desired amount and/or said driver has taken control over said vehicle. The conditions to energize the driver are typically different than the optimal conditions to view the traffic and drive the car. A gradual transition between these two modes is more pleasant for the driver.

In a second aspect of the invention, an interior lighting system comprises said system and said light source.

In a third aspect of the invention, a method of controlling interior lighting inside a vehicle, said interior lighting comprising a light source, comprises obtaining navigation information, determining an estimation of an end time of an autonomous driving mode based on said navigation information, said vehicle switching to a manual driving mode at said end time, determining, based on said estimation of said end time, an energizing light start time ahead of said end time, and controlling said light source inside said vehicle to render energizing light starting at said energizing light start time. Said method may be performed by software running on a programmable device. This software may be provided as a computer program product.

Moreover, a computer program for carrying out the methods described herein, as well as a non-transitory computer readable storage-medium storing the computer program are provided. A computer program may, for example, be downloaded by or uploaded to an existing device or be stored upon manufacturing of these systems.

A non-transitory computer-readable storage medium stores at least one software code portion, the software code portion, when executed or processed by a computer, being configured to perform executable operations for controlling interior lighting inside a vehicle, said interior lighting comprising a light source. The executable operations comprise obtaining navigation information, determining an estimation of an end time of an autonomous driving mode based on said navigation information, said vehicle switching to a manual driving mode at said end time, determining, based on said estimation of said end time, an energizing light start time ahead of said end time, and controlling said light source inside said vehicle to render energizing light starting at said energizing light start time.

As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a device, a method or a computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "circuit", "module" or "system." Functions described in this disclosure may be implemented as an algorithm executed by a processor/microprocessor of a computer. Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied, e.g., stored, thereon.

Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a computer readable storage medium may include, but are not limited to, the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of the present invention, a computer readable storage medium may be any tangible medium that can contain, or store, a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber, cable, RF, etc., or any suitable combination of the foregoing. Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java(TM), Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor, in particular a microprocessor or a central processing unit (CPU), of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer, other programmable data processing apparatus, or other devices create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of devices, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention are apparent from and will be further elucidated, by way of example, with reference to the drawings, in which:

Fig. 1 is a block diagram of a first embodiment of the system;

Fig. 2 is a block diagram of a second embodiment of the system;

Fig. 3 is a flow diagram of a first embodiment of the method;

Fig. 4 is a flow diagram of a second embodiment of the method;

Fig. 5 shows an example of an intensity of energizing light changing over time;

Fig. 6 shows examples of an autonomous driving mode end time and an energizing light start time;

Fig. 7 is a flow diagram of a third embodiment of the method; Fig. 8 is a flow diagram of a fourth embodiment of the method;

Fig. 9 is a flow diagram of a fifth embodiment of the method; and

Fig. 10 is a block diagram of an exemplary data processing system for performing the method of the invention.

Corresponding elements in the drawings are denoted by the same reference numeral.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Fig. 1 shows a first embodiment of the system for controlling interior lighting inside a vehicle. The interior lighting of a vehicle 11 comprises light sources 21-24. The light sources 21-24 may be LED strips, for example. In the example of Fig. 1, the light sources 21- 24 are used for ambience lighting. Ambience lighting typically has a low intensity and is typically colored light. While a reading light is a functional light, ambience lighting is typically used to provide a pleasing aesthetic effect and improve the driving experience.

In the embodiment of Fig. 1, the system is an infotainment system 1. The infotainment system 1 and light sources 21-24 form an interior lighting system. The infotainment system 1 comprises a receiver 3, a transmitter 4, a processor 5, and memory 7. The processor 5 is configured to obtain navigation information and determine an estimation of an end time of an autonomous driving mode based on the navigation information. In the embodiment of Fig. 1, the navigation information is based on centrally collected traffic information. Routes may be calculated locally or remotely based on locally or remotely stored maps and the centrally collected traffic information. The navigation information may comprise the centrally collected traffic information.

The vehicle switches to a manual driving mode at the end time if not already in manual driving mode at that time. In the embodiment of Fig. 1, the infotainment system 1 transmits a request to a driving control unit 17 to end the autonomous driving mode and activate the manual driving mode. Thus, the autonomous driving mode is ended based on the navigation information. The infotainment system 1 alerts the driver before transmitting the request, e.g. with light, visuals, sound and/or haptics. Additionally, the vehicle 11 may comprise sensors and the autonomous driving mode may be ended based on sensor information, e.g. if the sensors are no longer able to detect surrounding objects with sufficient reliability. In an alternative embodiment, the autonomous driving mode can only be ended manually by the driver. The processor 5 is further configured to determine, based on the estimation of the end time, an energizing light start time ahead of the end time, and control, via the transmitter 4, the light source 22 inside the vehicle 11 to render energizing light starting at the energizing light start time. In other words, the vehicle ambience lighting can be adjusted timely before the driver needs to take over control over the vehicle. The system may be able to take user preferences into account. For instance, some users may prefer to work, game or sleep longer and have an abrupt awakening ambience change, while others appreciate gradual transitions and a timelier notifying ambience.

In the autonomous driving mode, the ambience is optimized for the driver’s current activity or state, which could be working, reading, watching online content, having a voice conversation, relaxing or being asleep. This means that, for instance, in the case of reading a book, or having a social in-vehicle activity, the light conditions inside the vehicle are optimized for viewing inside. In the case of an upcoming take-over moment, the ambience is (e.g. gradually) adjusted such that the driver’s attention will move towards the traffic situation outside the vehicle, and the in-vehicle light conditions near the driver are optimized for viewing outside.

In the embodiment of Fig. 1, the energizing light is rendered on the light source 22 and thereby localized to the driver only, as far as possible. The light source 22 is selected, because the light source 22 is located in front of a driver seat 13. The selection of the light source 22 may be preconfigured in the infotainment system 1, for example. In an alternative embodiment, all of the light sources 21-24 are used to render the energizing light. The state and activity of passengers may also be taken into account. For instance, the energizing light may be rendered on only light source 22 in dependence on passengers being immersed in an activity or being in a deep sleep. This may also depend on other factors, such as the time left to the destination.

The timing and adjustments may be based on the current conditions of the driver (e.g. alertness, sleep phase, content immersion) and the conditions of the surroundings (e.g. ambient light level, weather, traffic, route complexity, general relevant properties of the environment etc.). The current conditions of the driver may be determined by the vehicle, e.g. by using a camera or by analyzing movements of the steering wheel, or by a personal, e.g. wearable or implanted, device. This personal device might be able to measure the body conditions and state of the driver more precisely. The system may also be able to leam over time how fast, with a certain intensity and/or duration of energizing light, a (specific) driver is able to change from a specific state (e.g. working, reading, sleeping) to a state whereby he takes proper control of the vehicle.

Near the end time of the autonomous driving mode, the system may be able to control the light source 22 to communicate relevant aspects of the driving conditions or environment to the user, e.g. an exit coming up or slippery roads. The system may be able to detect whether the user’s alertness is actually changing, e.g. the user is taking over control of the vehicle, and the ambience transition may be adapted to this (e.g. fade out ambience boost if user has taken control and is fully alert).

In the embodiment of Fig. 1, the vehicle switches to a manual driving mode at the end time if not already in manual driving mode at that time. The system may implement a gradual release of control to the driver (e.g. first steering, then braking, signaling, etc.), as both a means to safely evaluate the alertness of the driver as well as to allow the driver to gradually get control of the vehicle. For safety reasons, this option might also include a user overwrite allowing a driver to take immediately full control of the vehicle.

In the embodiment of the infotainment system 1 shown in Fig. 1, the infotainment system 1 comprises one processor 5. In an alternative embodiment, the infotainment system 1 comprises multiple processors. The processor 5 of the infotainment system 1 may be a general-purpose processor or an application-specific processor. The receiver 3 and the transmitter 4 may use one or multiple wired or wireless communication technologies for communicating with the driving control unit 17, the light sources 21-24 and/or with other systems, e.g. a traffic information service. In an alternative embodiment, multiple receivers and/or multiple transmitters are used instead of a single receiver and a single transmitter.

In the embodiment shown in Fig. 1, a separate receiver and a separate transmitter are used. In an alternative embodiment, the receiver 3 and the transmitter 4 are combined into a transceiver. The infotainment system 1 may comprise other components typical for an infotainment system such as a power connector, a display and one or more user input devices. The invention may be implemented using a computer program running on one or more processors.

In the embodiment of Fig. 1, ambience lighting is used to render the energizing light. In a variant on this embodiment, a dedicated light source is alternatively or additionally used to render the energizing light. In the embodiment of Fig. 1, the system of the invention is an infotainment system. In an alternative embodiment, the system of the invention is a different type of device. Fig. 2 shows a second embodiment of the system for controlling interior lighting inside a vehicle. The interior lighting of a vehicle 41 comprises an energizing light source 45 and ambient light sources 51-54. The light sources 51-54 may be LED strips, for example. The energizing light source 45 may comprise one or more LEDs. The light source 45 may be a white light source with a blue pump (e.g. a blue LED with a yellow phosphor coating) in the range 447-531 nm, e.g. chromatic cyan light, for example. The light source 45 is chosen and positioned to achieve a certain total melanopic flux at the position of the eyes of the driver.

Spectrally pure light (e.g. a laser with one or two wavelengths) of 490 nm is more effective than a regular white light source (with a traditional blue pump) at the same intensity. However, spectrally pure light of 490 nm at low intensity will be less effective than a regular white light source (with a traditional blue pump) at normal intensity if the regular white light source has an increased melanopic flux (due to e.g. a smaller distance of the eyes of the driver to the light source). If it is possible to render white light, e.g. if this does not make visibility outside the vehicle more difficult, then this may be preferred.

In the embodiment of Fig. 2, the system is an interior lighting control system 31. The interior lighting control system 31 and the light sources 45, 51-54 form an interior lighting system. The interior lighting control system 31 comprises a receiver 33, a transmitter 34, a processor 35, and memory 37. The processor 35 is configured to obtain driving mode information from the driving control unit 17. The driving mode information indicates whether the vehicle is in autonomous driving mode or in manual driving mode.

The processor 35 is configured to obtain navigation information from a navigation system 15 and if the vehicle is determined to be in autonomous driving mode, determine, based on the navigation information, an estimation of an end time of the autonomous driving mode at which the vehicle switches to the manual driving mode (if not already in manual driving mode at that time).

In the embodiment of Fig. 2, interior lighting control system 31 does not transmit a request to the driving control unit 17 to end the autonomous driving mode and activate the manual driving mode. In the embodiment of Fig. 2, the autonomous driving mode can only be ended manually.

The processor 35 is further configured to determine, based on the estimation of the end time, an energizing light start time ahead of the end time, and control, via the transmitter 34, the light source 45 inside the vehicle 41 to render energizing light starting at the energizing light start time. In the embodiment of the interior lighting control system 31 shown in Fig. 2, the interior lighting control system 31 comprises one processor 35. In an alternative embodiment, the interior lighting control system 31 comprises multiple processors. The processor 35 of the interior lighting control system 31 may be a general-purpose processor or an application-specific processor. The receiver 33 and the transmitter 34 may use one or multiple wired or wireless communication technologies for communicating with the driving control unit 17, the navigation system 15 and/or the light sources 45,51-54. In an alternative embodiment, multiple receivers and/or multiple transmitters are used instead of a single receiver and a single transmitter.

In the embodiment shown in Fig. 2, a separate receiver and a separate transmitter are used. In an alternative embodiment, the receiver 33 and the transmitter 34 are combined into a transceiver. The interior lighting control system 31 may comprise other components typical for an interior lighting control system such as a power connector. The invention may be implemented using a computer program running on one or more processors.

In the embodiment of Fig. 2, the vehicle has ambient lighting. In an alternative embodiment, the vehicle does not have ambient lighting. In the embodiment of Fig. 2, a dedicated light source is used to render the energizing light. In a variant on this embodiment, ambience lighting is alternatively or additionally used to render the energizing light. In the embodiment of Fig. 2, the system of the invention is an interior lighting control system. In an alternative embodiment, the system of the invention is a different type of device.

A first embodiment of the method of controlling interior lighting inside a vehicle is shown in Fig. 3. The interior lighting comprises a light source. A step 101 comprises obtaining navigation information, e.g. based on centrally collected traffic information. A step 103 comprises determining an estimation of an end time of an autonomous driving mode based on the navigation information obtained in step 101. The vehicle switches to a manual driving mode at the end time. The estimated end time of the autonomous driving mode is the moment at which the user needs to take control of the vehicle if he has not done so already.

The navigation information may be received from a navigation system of the vehicle and may specify the estimation of the end time of the autonomous driving mode. This estimation may then be extracted from the navigation information in step 103. Alternatively, the navigation information may comprise a planned route and traffic information. The estimation may then be calculated based on the route and traffic information in step 103. The traffic information may indicate traffic jams and accidents, for example. The estimated end time of the autonomous driving mode depends on the planned route and the traffic information.

A step 105 comprises determining, based on the estimation of the end time determined in step 103, an energizing light start time ahead of the end time. The energizing light start time preferably starts between 5 and 15 minutes before the estimated end time. A route may normally be recalculated (i.e. planned again) in view of traffic information. If a new route would result in an earlier end time and this would mean that it would not be possible to render the energizing light with a desired duration, this new route is preferably rejected.

The system performing the method may also be able to learn over time, how fast a (specific) driver is able to wake up, take his position and to take proper control of the vehicle with a certain intensity and/or duration of energizing light. This information may be used to determine the energizing light start time in step 105. A step 107 comprises controlling the light source inside the vehicle to render energizing light starting at the energizing light start time. The energizing light preferably comprises wavelengths in the range 447-531 nm.

In the embodiment of Fig. 3, only energizing light is rendered to increase the wakefulness of a user to a desired level. In an alternative embodiment, an ambience boost involving various ambience modalities may be provided during a relatively short period, e.g. at the start or end of the energizing or if the user is not waking up fast enough. Examples of ambience modalities that may be controlled are:

• climate: activate a fresh breeze of air directed towards the driver.

• sound: energizing music or alarm clock sounds to alert or wake up the user.

• tactile: massage chairs providing an energizing massage.

• electronic displays may show energizing content.

• smart windows: switchable (display) windows may switch to transparent mode or emit energizing light.

• force feedback may be generated by rapid breaking (and speeding) of the car.

The duration and/or the intensity of the energizing light rendered in step 107 may be adjusted based on the external traffic and/or route conditions as well as on the driver’s current state and activity. For instance, if the user is in a deep sleep, and the traffic is busy, the energizing light may be started earlier, and/or the energizing light may be rendered more intense. In the above-described alternative embodiment, the duration and/or intensity of the ambience boost may be adjusted in a similar manner. A second embodiment of the method of controlling interior lighting inside a vehicle is shown in Fig. 4. Step 101 comprises obtaining navigation information. Step 103 comprises determining an estimation of an end time of an autonomous driving mode based on the navigation information obtained in step 101. The vehicle switches to a manual driving mode at the end time. Step 105 comprises determining, based on the estimation of the end time determined in step 103, an energizing light start time ahead of the end time.

A step 121 comprises selecting a light source from a plurality of light sources, e.g. based on a driver location and locations of the plurality of light sources. The plurality of light sources is used to render ambience light. For example, light source 22 may be selected from light sources 21-24 in the example of Fig. 1.

Step 107 comprises controlling the light source inside the vehicle to render energizing light starting at the energizing light start time determined in step 105. In the embodiment of Fig. 4, step 107 is implemented by steps 125 and 127. Step 125 comprises rendering a gradual transition, e.g. with a duration of one minute or less, from the ambience light to the energizing light on the light source selected in step 121. Step 125 comprises controlling the light source selected in step 121, and optionally other light sources, to stop rendering ambience light in the vehicle. Step 127 comprises rendering only the energizing light.

Fig. 5 shows an example of an intensity of energizing light changing over time. The intensity of the energizing light is represented by a line 71. Starting at the energizing light start time 73, e.g. determined in step 105 of Fig. 4, the energizing light intensity is gradually increased. At the same time, ambience light may be gradually decreased (not shown in Fig. 5), as is done in step 125 of Fig. 4.

When the energizing light intensity reaches the desired intensity, it may be rendered at a continuous level until the user appears to be completely alert. The energizing light may be faded out and gradually change to conditions optimized for driving as soon as the user appears to be completely alert, as shown in Fig. 5. The conditions to energize the driver are typically different than the optimal conditions to view the traffic and drive the car. A gradual transition between these two modes is more pleasant for the driver if he is not taking a nap. At the end time 74 of the autonomous driving mode, the intensity of the energizing light is at (almost) the same level as at the energizing light start time 73.

Fig. 6 shows a map 91 with a start location 93, a target location 97 and a route 95 between the two locations. The middle part of the route 95 consists of one or more freeways. The first and last parts of the route 95 consists of roads other than freeways. Normally, the vehicle would automatically switch from autonomous driving mode to manual driving mode at the end of the middle part, i.e. at time 75. However, since there has been a traffic accident, the vehicle will already automatically switch from autonomous driving mode to manual driving mode at autonomous driving mode end time 74. The energizing light starts at start time 73, which is typically between 5 and 15 minutes before the estimated end time 74.

A third embodiment of the method of controlling interior lighting inside a vehicle is shown in Fig. 7. Step 101 comprises obtaining navigation information. Step 103 comprises determining an estimation of an end time of an autonomous driving mode based on the navigation information obtained in step 101. The vehicle switches to a manual driving mode at the end time.

Next, one or more of steps 141, 143, and 145 are performed. Step 141 comprises determining an ambient light level. Step 143 comprises determining a scheduled activity at a driving destination. Step 145 comprises determining a remaining autonomous driving time.

Step 105 comprises determining, based on the estimation of the end time determined in step 103, an energizing light start time ahead of the end time. In the embodiment of Fig. 8, step 105 is implemented by a step 147. Step 147 comprises determining the energizing light start time at which the energizing light is going to be rendered based on an ambient light level determined in step 141, a scheduled activity at a driving destination determined in step 143, and/or a remaining autonomous driving time determined in step 145.

In the embodiment of Fig. 7, step 147 further comprises determining an intensity of the energizing light based on an ambient light level determined in step 141, a scheduled activity at a driving destination determined in step 143, and/or a remaining autonomous driving time determined in step 145. In an alternative embodiment, the intensity of the energizing light is not based on any of these parameters.

In the embodiment of Fig. 7, step 147 comprises determining whether to render the energizing light as either white light or non-white light in dependence on the ambient light level determined in step 141, e.g. cyan light at low ambient light levels. Step 107 comprises controlling the light source inside the vehicle to render energizing light starting at the energizing light start time determined in step 147 and with the intensity or intensities determined in step 147. The intensity of the energizing light may be adjusted over time. The energizing light is rendered either as white light or non-white light in accordance with the determination made in step 147. The term white light relates to light having a correlated color temperature (CCT) between about 2000 K and 20000 K and within about 10 to 15 SDCM (standard deviation of color matching) from the BBL (black body locus).

A fourth embodiment of the method of controlling interior lighting inside a vehicle is shown in Fig. 8. The interior lighting comprises a light source. Step 101 comprises obtaining navigation information. Step 103 comprises determining an estimation of an end time of an autonomous driving mode based on the navigation information obtained in step 101. The vehicle switches to a manual driving mode at the end time.

A step 161 comprises determining an alertness level of the driver of the vehicle. Step 105 comprises determining, based on the estimation of the end time determined in step 103, an energizing light start time ahead of the estimated end time. In the embodiment of Fig. 8, step 105 is implemented by a step 163. Step 163 comprises determining the energizing light start time and an initial intensity at which the energizing light is going to be rendered based on the alertness level of the driver determined in step 161. Step 107 comprises controlling the light source inside the vehicle to render energizing light starting at the energizing light start time determined in step 163 with the initial intensity determined in step 163.

Next, a step 171 is performed. Step 171 comprises determining the alertness level of the driver to determine a reaction of the driver to the energizing light. The reaction may be determined based on obtained sensor data from one or more sensors. The alertness level may be determined, for example, based on the driver’s current posture (e.g. sitting right up) and/or using gaze detection. The driver’s current posture and/or the user’s gaze may be detected using the sensor data from the one or more sensors (e.g. one or more cameras, one or more sensors comprised in the driver’s chair, etc.).

In a step 173, it is determined whether this alertness level exceeds a threshold T. If so, a step 177 is performed. If not, it is determined in a step 175 whether the alertness level has increased recently, e.g. in the last X seconds. If so, step 171 is repeated, i.e. the alertness of the driver is determined again at a later time, and the method proceeds as shown in Fig. 8. If the driver has taken control over the vehicle, the alertness level will exceed threshold T.

If is determined in a step 175 that the alertness level has not increased recently, a step 179 is performed. Step 179 comprises controlling the light source to increase the intensity of the energizing light. After step 179, step 171 is repeated and the method proceeds as shown in Fig. 8. If it is determined in step 173 that the alertness level exceeds a threshold T, step 177 is performed, which comprises controlling the light source to reduce the energizing light. In the embodiment of Fig. 8, the light source is controlled to gradually reduce the energizing light. After the rendering/emission of the energizing light has stopped, step 101 may be performed again after the estimated end time, e.g. when the driving mode is switched to autonomous driving after the estimated end time, and the method then proceeds as shown in Fig. 8.

A fifth embodiment of the method of controlling interior lighting inside a vehicle is shown in Fig. 9. A step 181 comprises determining whether an autonomous driving mode is active. If so, step 101 is performed. If not, step 181 is repeated at a later time. Step 101 comprises obtaining navigation information. Step 103 comprises determining an estimation of an end time of an autonomous driving mode based on the navigation information obtained in step 101. The vehicle switches to a manual driving mode at the end time.

Step 105 comprises determining, based on the estimation of the end time determined in step 103, an energizing light start time ahead of the end time. Step 107 comprises controlling the light source inside the vehicle to render energizing light starting at the energizing light start time. In a step 183, the vehicle automatically switches to manual driving mode at the end time or the user switches to manual driving mode manually before the end time, before or after the energizing light has stopped. Step 181 is repeated after step 183, after which the method proceeds as shown in Fig. 9.

The embodiments of Figs. 3-4 and 7-9 differ from each other in multiple aspects, i.e. multiple steps have been added or replaced. In variations on these embodiments, only a subset of these steps is added or replaced and/or one or more steps is omitted. As a first example, step 121 may be omitted from the embodiment of Fig. 4 and/or added to one or more of the embodiments of Figs. 3, 7-9. As a second example, the embodiments of Figs. 4 and 7-9 may be combined.

Fig. 10 depicts a block diagram illustrating an exemplary data processing system that may perform the method as described with reference to Figs. 3-4 and 7-9.

As shown in Fig. 10, the data processing system 300 may include at least one processor 302 coupled to memory elements 304 through a system bus 306. As such, the data processing system may store program code within memory elements 304. Further, the processor 302 may execute the program code accessed from the memory elements 304 via a system bus 306. In one aspect, the data processing system may be implemented as a computer that is suitable for storing and/or executing program code. It should be appreciated, however, that the data processing system 300 may be implemented in the form of any system including a processor and a memory that is capable of performing the functions described within this specification.

The memory elements 304 may include one or more physical memory devices such as, for example, local memory 308 and one or more bulk storage devices 310. The local memory may refer to random access memory or other non-persistent memory device(s) generally used during actual execution of the program code. A bulk storage device may be implemented as a hard drive or other persistent data storage device. The processing system 300 may also include one or more cache memories (not shown) that provide temporary storage of at least some program code in order to reduce the quantity of times program code must be retrieved from the bulk storage device 310 during execution. The processing system 300 may also be able to use memory elements of another processing system, e.g. if the processing system 300 is part of a cloud-computing platform.

Input/output (I/O) devices depicted as an input device 312 and an output device 314 optionally can be coupled to the data processing system. Examples of input devices may include, but are not limited to, a keyboard, a pointing device such as a mouse, a microphone (e.g. for voice and/or speech recognition), or the like. Examples of output devices may include, but are not limited to, a monitor or a display, speakers, or the like. Input and/or output devices may be coupled to the data processing system either directly or through intervening I/O controllers.

In an embodiment, the input and the output devices may be implemented as a combined input/output device (illustrated in Fig. 10 with a dashed line surrounding the input device 312 and the output device 314). An example of such a combined device is a touch sensitive display, also sometimes referred to as a “touch screen display” or simply “touch screen”. In such an embodiment, input to the device may be provided by a movement of a physical object, such as e.g. a stylus or a finger of a user, on or near the touch screen display.

A network adapter 316 may also be coupled to the data processing system to enable it to become coupled to other systems, computer systems, remote network devices, and/or remote storage devices through intervening private or public networks. The network adapter may comprise a data receiver for receiving data that is transmitted by said systems, devices and/or networks to the data processing system 300, and a data transmitter for transmitting data from the data processing system 300 to said systems, devices and/or networks. Modems, cable modems, and Ethernet cards are examples of different types of network adapter that may be used with the data processing system 300.

As pictured in Fig. 10, the memory elements 304 may store an application 318. In various embodiments, the application 318 may be stored in the local memory 308, the one or more bulk storage devices 310, or separate from the local memory and the bulk storage devices. It should be appreciated that the data processing system 300 may further execute an operating system (not shown in Fig. 10) that can facilitate execution of the application 318. The application 318, being implemented in the form of executable program code, can be executed by the data processing system 300, e.g., by the processor 302. Responsive to executing the application, the data processing system 300 may be configured to perform one or more operations or method steps described herein.

Fig. 10 shows the input device 312 and the output device 314 as being separate from the network adapter 316. However, additionally or alternatively, input may be received via the network adapter 316 and output be transmitted via the network adapter 316. For example, the data processing system 300 may be a cloud server. In this case, the input may be received from and the output may be transmitted to a user device that acts as a terminal.

Various embodiments of the invention may be implemented as a program product for use with a computer system, where the program(s) of the program product define functions of the embodiments (including the methods described herein). In one embodiment, the program(s) can be contained on a variety of non-transitory computer-readable storage media, where, as used herein, the expression “non-transitory computer readable storage media” comprises all computer-readable media, with the sole exception being a transitory, propagating signal. In another embodiment, the program(s) can be contained on a variety of transitory computer-readable storage media. Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media (e.g., read-only memory devices within a computer such as CD-ROM disks readable by a CD-ROM drive, ROM chips or any type of solid-state non-volatile semiconductor memory) on which information is permanently stored; and (ii) writable storage media (e.g., flash memory, floppy disks within a diskette drive or hard-disk drive or any type of solid-state random-access semiconductor memory) on which alterable information is stored. The computer program may be run on the processor 302 described herein.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of embodiments of the present invention has been presented for purposes of illustration, but is not intended to be exhaustive or limited to the implementations in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the present invention. The embodiments were chosen and described in order to best explain the principles and some practical applications of the present invention, and to enable others of ordinary skill in the art to understand the present invention for various embodiments with various modifications as are suited to the particular use contemplated.