Controlling vehicle operation based on driver attention

Abstract

The invention discloses controlling vehicle operation based on driver attention. A system for controlling a forward collision warning system based on a driver attention value is provided. The system includes a plurality of sensors and an electronic processor. The electronic processor is configured to determine a gaze angle of the driver using the plurality of sensors; determining a driver attention value based on the gaze angle; determining a forward collision warning system activation threshold based on the driver attention value; and selectively activating the forward collision warning system based on the forward collision warning system activation threshold.

Description

Background Art

[0001] Contemporary vehicles include many safety features designed to help keep occupants safe and help avoid collisions. These safety features are often components of one of a number of advanced driver assistance systems (ADAS). ADAS includes, for example, adaptive cruise control, adaptive steering or lane keeping features, and forward collision warning. In some examples, all or a combination of these features are included in the vehicle. Adaptive cruise control maintains the speed of the vehicle at a value set by the driver. Adaptive steering helps keep the vehicle within a road or highway lane and, in some examples, can override or modify the steering input from the driver. Forward collision warning can alert the driver when the vehicle in which the driver is operating is getting too close to a vehicle ahead. Summary of the Invention

[0002] An example embodiment provides a system for controlling a forward collision warning system based on a driver attention value. The system includes a plurality of sensors and an electronic processor. The electronic processor is configured to use the plurality of sensors to determine a driver's gaze angle; determine a driver attention value based on the gaze angle; determine a forward collision warning system activation threshold based on the driver attention value; and selectively activate the forward collision warning system based on the forward collision warning system activation threshold.

[0003] The electronic processor is further configured to monitor a forward collision warning system activation value and activate the forward collision warning system when the forward collision warning system activation value is less than the forward collision warning system activation threshold.

[0004] The gaze angle is measured between the longitudinal axis of the vehicle and the direction in which the driver is looking.

[0005] The plurality of sensors includes at least a time-of-flight camera having a view of the interior of the vehicle.

[0006] The time-of-flight camera determines the direction in which the driver is looking, the driver's head position, the driver's body position, or a combination thereof to determine the gaze angle.

[0007] The gaze angle is compared with a look-up table of pre-determined gaze angles to determine the driver attention value.

[0008] The driver attention value decreases as the gaze angle increases.

[0009] The driver attention value is compared with a look-up table of pre-determined driver attention values to determine the forward collision warning system activation threshold.

[0010] The forward collision warning system activation threshold increases as the driver attention value decreases.

[0011] Another example embodiment provides a system for controlling a forward collision warning system based on a driver attention value. The system includes a plurality of sensors and an electronic processor. The electronic processor is configured to determine a driver attention value for a driver, modify a forward collision warning system activation threshold based on the driver attention value, and selectively activate the forward collision warning system based on the forward collision warning system activation threshold.

[0012] The driver attention value is at least partially based on the driver's gaze angle, and the gaze angle is determined based on the direction the driver is looking, the driver's head position, the driver's body position, or a combination thereof.

[0013] The plurality of sensors includes a time-of-flight camera, and the time-of-flight camera detects the direction the driver is looking, the driver's head position, the driver's body position, or a combination thereof.

[0014] The system further includes a memory coupled to the electronic processor, and the memory includes a first look-up table that includes a plurality of predetermined gaze angles and a plurality of driver attention values, where each of the plurality of driver attention values is associated with a corresponding predetermined gaze angle.

[0015] The memory further includes a second look-up table that includes a plurality of forward collision warning system activation thresholds and a plurality of driver attention values, where each forward collision warning system activation threshold is associated with a corresponding driver attention value.

[0016] Another example embodiment provides a method for controlling a forward collision warning system based on a driver attention value. The method includes determining a driver attention value for a driver, determining a forward collision warning system activation threshold based on the driver attention value, and selectively activating the forward collision warning system based on the forward collision warning system activation threshold.

[0017] The method further includes monitoring a gaze position associated with the driver using a time-of-flight camera that has a field of view inside the vehicle, with the driver located in the vehicle, where the gaze position is based on the direction the driver is looking, the driver's head position, the driver's body position, or a combination thereof.

[0018] The method further includes determining a gaze angle from the gaze position, where the gaze angle is measured between a gaze axis aligned with the driver's gaze position and a driving axis aligned with the longitudinal axis of the vehicle.

[0019] The method further includes comparing the gaze angle with a gaze angle look-up table to determine the driver attention value.

[0020] The method further includes comparing the driver attention value with a driver attention value look-up table to determine the forward collision warning system activation threshold.

[0021] The method further includes monitoring a forward collision warning system activation value and selectively activating the forward collision warning system when the forward collision warning system activation value is less than a forward collision warning system activation threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of a decentralized vehicle operating system.

[0023] Figure 2 is a schematic diagram of a centralized vehicle operating system.

[0024] Figure 3 is a flowchart showing an example method for determining driver attention based on the driver's gaze angle.

[0025] Figure 4 is a first top view of an example vehicle.

[0026] Figure 5 is Figure 4 a second top view of the example vehicle of

[0027] Figure 6 is Figure 4 a third top view of the example vehicle of

[0028] Figure 7 is a diagram showing an example of a driver's gaze area.

[0029] Figure 8 is a flowchart showing an example method for controlling vehicle operation based on a driver attention value. DETAILED DESCRIPTION

[0030] Before explaining any aspect, feature, or example in detail, it should be understood that the aspect, feature, or example is not limited in its application to the details of the structure and arrangement of the components set forth in the following description or shown in the following drawings. Other examples are possible and can be practiced or implemented in various ways.

[0031] It should also be noted that multiple hardware- and software-based devices, as well as multiple parts of different structures, can be used in various embodiments. Aspects, features, or examples can include hardware, software, and electronic parts or modules, which for purposes of discussion may be shown and described as if most of the parts were implemented only in hardware. However, those skilled in the art, and upon reading this detailed description, will recognize that in at least one example, the electronic-based aspects of the present invention can be implemented in software (e.g., stored on a non-transitory computer-readable medium) capable of being executed by one or more processors. As a result, it should be noted that multiple hardware- and software-based devices, as well as multiple parts of different structures, can be used to implement the present invention. For example, the "control unit" and "controller" described in the specification can include one or more electronic processors, one or more memories including a non-transitory computer-readable medium, one or more input / output interfaces, and various connections (e.g., a system bus) connecting the parts.

[0032] Unless the context in which it is used unambiguously indicates otherwise, the articles "a," "an," and "the" should not be construed to mean "one" or "only one." Instead, these articles should be construed to mean "at least one" or "one or more." Similarly, when the term "the" or "said" is used to refer to a noun previously introduced by the indefinite article "a" or "an," "the" and "said" mean "at least one" or "one or more," unless the usage unambiguously indicates otherwise.

[0033] It should also be understood that although some of the figures show hardware and software located within a particular device, these descriptions are for illustrative purposes only. In some embodiments, the parts shown can be combined or separated into discrete software, firmware, and / or hardware. For example, instead of being located within and executed by a single electronic processor, the logic and processing can be distributed among multiple electronic processors. Regardless of how they are combined or separated, the hardware and software parts can be located on the same computing device, or can be distributed among different computing devices, which are connected by one or more networks or other suitable connections or links.

[0034] Thus, in the claims, if a device or system, for example, is claimed to include an electronic processor or other element configured in a certain manner (e.g., to make multiple decisions), the claim and claim element should be construed to mean one or more electronic processors (or other elements), where any one of the one or more electronic processors (or other elements) is configured as claimed, e.g., to jointly make some or all of the multiple decisions. Again, those electronic processors and processing can be distributed.

[0035] In addition, it should be understood that the terms and phrases used herein are for descriptive purposes and should not be considered limiting. The terms "mounted," "connected," and "coupled" are used broadly and include both direct and indirect mounting, connecting, and coupling. Additionally, "connected" and "coupled" are not limited to physical or mechanical connections or couplings and can include electrical connections or couplings, whether direct or indirect. Additionally, electronic communication and notification can be prefabricated using any known means, including wired connections, wireless connections, etc.

[0036] For simplicity of description, some or all of the example systems presented herein are shown using a single example of each of their components. Some examples may not describe or show all components of the system. Other examples may include more or fewer of the components shown, may combine some components, or may include additional or alternative components.

[0037] Figure 1 An example system 100 for controlling vehicle operation based on driver attention is shown. In the illustrated example, system 100 is present in a primary vehicle 102, which is adjacent to a secondary vehicle 104. It can be understood that both vehicles 102, 104 can include the same system 100 described herein. However, for simplicity and ease of understanding, the details of system 100 are described in the context of the primary vehicle 102, and the secondary vehicle 104 is included to assist in the description of the operation of system 100.

[0038] As illustrated, system 100 includes an interior monitoring system 110 and an advanced driver assistance system 112. The interior monitoring system 110 includes an electronic processor 114 connected to a memory 116. In one example, the memory 116 includes a lookup table 118 that stores values related to the driver's gaze angle (i.e., the direction the driver is looking relative to the forward direction or the direction the vehicle is moving). In some examples, other data structures for storing and accessing data are used as alternatives or supplements to the lookup table. These values include driver attention values associated with the driver's gaze angle. As further illustrated, the interior monitoring system 110 also includes an interior sensor 120 coupled to the electronic processor 114. In some examples, more than one interior sensor is used. In some examples, the interior sensor 120 includes a camera, a time-of-flight (ToF) sensor, a radar sensor, a lidar sensor, or a combination thereof, or is in the form of a camera, a time-of-flight (ToF) sensor, a radar sensor, a lidar sensor, or a combination thereof. Additionally, the interior sensor 120 can include a charge-coupled device (CCD), a complementary metal oxide sensor (CMOS), or a vertical cavity surface emitting laser (VCSEL).

[0039] The internal sensor 120 is used to monitor the driver and the direction the driver is looking during the operation of the vehicle 102 to determine the real-time gaze angle associated with the driver. The gaze angle is used to determine the driver attention value. For example, as the gaze angle increases (and the driver is not looking in the direction the vehicle is traveling), the driver attention value decreases.

[0040] As Figure 1 As illustrated, the advanced driver assistance system 112 includes an electronic processor 124 connected to a memory 126. The memory 126 includes a look-up table 128 (or other access and storage data structures) that stores values related to the forward collision warning (FCW) activation threshold based on the driver attention value. For example, as the driver attention value decreases, the forward collision warning system activation threshold increases, and increasing the activation threshold provides the driver with a greater warning (e.g., more time) regarding nearby vehicles, such as the secondary vehicle 104, in order to help reduce the likelihood of a collision between the primary vehicle 102 and the secondary vehicle 104. Additionally, increasing the activation threshold also allows for an increase in the reaction time for the driver of the primary vehicle 102 and an increase in the spacing between the primary vehicle 102 and the secondary vehicle 104.

[0041] In the illustrated example, the advanced driver assistance system 112 also includes an external sensor 130 coupled to the processor 124. In some examples, the external sensor 130 includes a camera, a time-of-flight (ToF) sensor, a radar sensor, a lidar sensor, or a combination thereof, or takes the form of a camera, a time-of-flight (ToF) sensor, a radar sensor, a lidar sensor, or a combination thereof. Additionally, the external sensor 130 can include a charge-coupled device (CCD), a complementary metal-oxide sensor (CMOS), or a vertical-cavity surface-emitting laser (VCSEL). In the illustrated example, the advanced driver assistance system 112 includes an adaptive cruise control system 132, an adaptive steering system 134, and a forward collision warning system 136 connected to the processor 124.

[0042] The external sensor 130 can be located on the front of the primary vehicle 102 (e.g., the external sensor 130 can be mounted to the grille or a location between the vehicle's headlights) to detect the distance between the primary vehicle 102 and the secondary vehicle 104. In some examples, more than one external sensor 130 is used, and the external sensors are located on each side of the primary vehicle 102 to detect vehicles adjacent to each side of the primary vehicle 102.

[0043] During operation of the primary vehicle 102, the adaptive cruise control system 132 controls the speed of the primary vehicle 102 (e.g., by controlling the throttle or acceleration and / or braking system of the primary vehicle 102) to maintain a predetermined distance between the primary vehicle 102 and the secondary vehicle 104 based on information sensed by the external sensor 130. For example, the external sensor 130 (or an electronic processor, which is a component of or connected to the electronic sensor 130) determines the distance between the primary vehicle 102 and the secondary vehicle 104. If the distance between the primary vehicle 102 and the secondary vehicle 104 is less than the FCW system activation threshold, the FCW system 136 can alert the driver of an impending collision situation, e.g., by emitting an alarm or activating a warning light. If the distance between the primary vehicle 102 and the secondary vehicle 104 is further reduced, the adaptive cruise control system 132 can apply the brakes of the primary vehicle 102 to help prevent a collision. It should be understood that the adaptive steering system 134 assists the driver when steering the primary vehicle 102 and can prevent lane changes when another vehicle is sensed by the external sensor 130 on either side of the primary vehicle 102.

[0044] In Figure 1 the illustrated example, the system 100 also includes a speaker 140 and a display 142, which are connected to the internal monitoring system 110 and the advanced driver assistance system 112. The speaker 140 emits one or more warning signals, such as an audible alarm, a voice message, or a combination thereof. Additionally, a wireless communication system 144 is connected to the internal monitoring system 110 and the advanced driver assistance system 112. The display 142 can include a heads-up display, an infotainment system display, a warning light, or any combination thereof. For example, the speaker 140 can work in conjunction with the FCW system 136 to send an audible alarm or signal to the driver during operation of the primary vehicle 102 when the primary vehicle 102 is too close to another vehicle (e.g., the secondary vehicle 104).

[0045] The various parts of the system 100, along with other various modules and parts, are electrically and communicatively coupled to each other via direct connections or by or through one or more control or data buses (e.g., bus 150), which enable communication therebetween. In some examples, the bus 150 is a Controller Area Network (CAN TM ) bus. In some examples, the bus 150 is an automotive Ethernet TM , FlexRay TM communication bus, or other suitable bus. In alternative examples, some or all of the parts of the system 100 can be communicatively coupled using a suitable wireless modality (e.g., Bluetooth TM or near-field communication connection).

[0046] Figure 2 Illustrates a similar system 200 that uses a single centralized processor. As shown, system 200 is present in the primary vehicle 102. A secondary vehicle 104 is included for the description of assisting the operation of the system. Figure 2 The system 200 depicted in includes an internal monitoring system 210 and an advanced driver assistance system 212 connected to a processor 214. A memory 216 is connected to the processor 214, and the memory 216 includes a look-up table 218. In this example, the look-up table 218 stores data associated with the internal monitoring system 210 and the advanced driver assistance system 212. For example, the look-up table 218 stores values related to the driver's gaze angle and values related to the activation of forward collision warning (FCW) based on the driver attention value.

[0047] The internal monitoring system 210 also includes an internal sensor 220 coupled to the processor 214. In some examples, the internal sensor 120 includes a camera, a time-of-flight (ToF) sensor, a radar sensor, a lidar sensor, or a combination thereof, or is in the form of a camera, a time-of-flight (ToF) sensor, a radar sensor, a lidar sensor, or a combination thereof. Additionally, the internal sensor 120 can include a charge-coupled device (CCD), a complementary metal-oxide sensor (CMOS), or a vertical-cavity surface-emitting laser (VCSEL). The internal sensor 220 is used to monitor the driver and the direction the driver is looking during the operation of the vehicle 202 to determine the real-time gaze angle associated with the driver. The gaze angle is used to determine the driver attention value.

[0048] Figure 2 Indicates that the advanced driver assistance system 212 includes an external sensor 230 coupled to the processor 224. In some examples, the external sensor 230 includes a camera, a time-of-flight (ToF) sensor, a radar sensor, a lidar sensor, or a combination thereof, or is in the form of a camera, a time-of-flight (ToF) sensor, a radar sensor, a lidar sensor, or a combination thereof. Additionally, the external sensor 230 can include a charge-coupled device (CCD), a complementary metal-oxide sensor (CMOS), or a vertical-cavity surface-emitting laser (VCSEL). Furthermore, the advanced driver assistance system 212 includes an adaptive cruise control system 232, an adaptive steering system 234, and a forward collision warning system 236 connected to the processor 224.

[0049] The external sensor 230 can be located on the front portion of the primary vehicle 102 (e.g., the external sensor 230 can be mounted to a position between the grille or the vehicle's headlights) to detect the distance between the primary vehicle 102 and the secondary vehicle 104. In some examples, more than one external sensor 230 is used and the external sensors are located on each side of the primary vehicle 102 to detect vehicles adjacent to each side of the primary vehicle 102.

[0050] During operation of the primary vehicle 202, the adaptive cruise control system 232 controls the speed and / or braking of the primary vehicle 202 to maintain a safe distance between the primary vehicle 202 and the secondary vehicle 204 based on the information sensed by the external sensor 230. For example, the external sensor 230 is capable of determining the distance between the primary vehicle 202 and the secondary vehicle 204. If the distance between the primary vehicle 202 and the secondary vehicle 204 is less than the FCW system activation threshold, the FCW system 236 can alert the driver of an impending collision situation by emitting an alarm. If the distance between the primary vehicle 202 and the secondary vehicle 204 further decreases, the adaptive cruise control system 232 can apply the brakes of the primary vehicle 202 to help prevent a collision. It should be understood that the adaptive steering system 234 assists the driver when steering the primary vehicle 202 and can prevent a lane change when another vehicle is sensed by the external sensor 230 on either side of the primary vehicle 202.

[0051] Figure 2 It is indicated that the system 200 further includes a speaker 240 and a display 242, which are connected to the internal monitoring system 210 and the advanced driver assistance system 212. The speaker 240 emits one or more warning signals, such as an audible alarm, a voice message, or a combination thereof. Additionally, the wireless communication system 244 is connected to the internal monitoring system 210 and the advanced driver assistance system 212. The display 242 can include a head-up display, an infotainment system display, a warning light, or any combination thereof. For example, the speaker 240 can work in conjunction with the FCW system 236 to send an audible alarm or signal to the driver during operation of the primary vehicle 202 when the primary vehicle 202 is too close to another vehicle (e.g., the secondary vehicle 204).

[0052] The various parts of the system 200, along with various other modules and parts, are electrically and communicatively coupled to each other via a direct connection or by or through one or more control or data buses (e.g., bus 250), which enable communication therebetween. In some examples, the bus 250 is a Controller Area Network (CAN TM ) bus. In some examples, the bus 250 is an automotive Ethernet TM 、FlexRay TMA communication bus or other suitable bus. In an alternative example, some or all of the components of system 200 may be communicatively coupled using a suitable wireless modality (e.g., Bluetooth TM or near field communication connection).

[0053] Figure 3 An example method for determining a Driver Attention Value (DAV), generally designated 300, is shown. The DAV is used to set a Forward Collision Warning (FCW) activation threshold. For example, the FCW system activation threshold can be a threshold distance between the host vehicle 102 and the target vehicle 104, and if the actual distance between the host vehicle 102 and the target vehicle 104 drops below the FCW system activation threshold, the FCW system activates and a warning is sent to the driver of the host vehicle 102. The steps of method 300 can be performed by Figure 1 the distributed system 100 depicted in Figure 2 or the centralized system 200 depicted in

[0054] As Figure 3 illustrated, method 300 begins at step 302, where during vehicle operation, method 300 includes monitoring a gaze position associated with the driver. The gaze position is the direction the driver is looking, and the gaze position can be determined using internal sensors (such as internal sensors 120, 220 of the first system 100 or the second system 200). As previously disclosed, internal sensors 120, 220 can include cameras with a field of view of the interior of the host vehicle 102, and the cameras are used to determine the gaze position by monitoring the direction of the driver's eyes, the direction of the driver's head, the direction of the driver's shoulders, or a combination thereof. For example, the camera can be a Time of Flight (ToF) camera that uses lidar, infrared light pulses, or a combination thereof to determine the direction the driver is looking relative to a fixed point or axis, the position of the driver's head relative to a fixed point or axis, the driver's body relative to a fixed point or axis, or any combination thereof.

[0055] Moving to step 304, method 300 includes determining a gaze angle A from the gaze position G . Referring to Figures 4 - 5 , the gaze angle A G is measured between the driving axis 402 of the host vehicle 102 and the gaze axis 404 aligned with the driver's 406 gaze position. It should be understood that the driving axis 402 is aligned with the longitudinal axis of the host vehicle 102. AsFigure 4 As shown in the figure, when the driver 406 is looking in the same direction as the vehicle is moving (i.e., forward), the gaze axis 404 is aligned with the driving axis 402, and the gaze angle A G is zero degrees (0°). Additionally, as Figure 4 shown in the figure, when the driver 406 is looking to one side, such as looking to the right side of the vehicle, looking at something in the passenger seat or something outside the vehicle, as detected by the eye position and head position, the gaze axis 404 is offset from the driving axis 402, and the gaze angle A G increases. In the example shown in Figure 5 the gaze angle A G is sixty-seven point five degrees (67.5°). As Figure 6 shown in the figure, when the driver 406 is looking further backward in the main vehicle 102, as detected by the head position and shoulder position, the gaze axis 404 is further offset from the driving axis 402, and the gaze angle A G is even greater than previously demonstrated. In the example of Figure 6 the gaze angle A G is one hundred and fifty degrees (150°). Clearly, as the gaze angle A G increases, the driver 406 will further divert attention from anything in front of the main vehicle 102.

[0056] Returning to the description of method 300, at step 306, method 300 includes determining a driver attention value (DAV) based on the gaze angle A G To determine a specific DAV in real time, processors 114, 214 are able to access lookup tables 118, 218 that store various DAVs associated with each gaze angle A G or range of gaze angles A G For example, for a gaze angle equal to zero (0°), the DAV can be one (1.0). As the gaze angle A G increases, the DAV can decrease. Table 1 below shows various DAVs for various gaze angles A G Table 2 shows various DAVs for various ranges of gaze angles A G

[0057] Table 1 DAV vs. Gaze Angle A G

[0058] <![CDATA[A G > DAV 0° 1.0 15° 0.875 30° 0.75 45° 0.625 60° 0.5 75° 0.375 90° 0.25 105° 0.125 120° 0.0

[0059] Table 2 DAV vs. Gaze Angle A G Range

[0060] <![CDATA[A G Range]]> DAV 0°-14° 1.0 15°-30° 0.875 31°-45° 0.75 46°-60° 0.625 61°-74° 0.5 75°-90° 0.375 91°-104° 0.25 105°-119 0.125 120° and above 0.0

[0061] Returning to the description of method 300, at step 308, method 300 includes determining a Forward Collision Warning (FCW) activation threshold based on the DAV. To determine a specific FCW system activation threshold in real time, processors 124, 214 are able to access lookup tables 128, 218 that store various FCW system activation thresholds associated with each DAV. For example, for a DAV equal to one (1), the FCW system activation threshold can be set to a minimum FCW system activation threshold of one hundred feet. The minimum FCW system activation threshold can be a user preference setting stored in the system. As the DAV decreases, the FCW system activation threshold increases.

[0062] Table 3 below shows various FCW system activation thresholds for various DAVs, measured in the distance between the primary vehicle 102 and the secondary vehicle 104, for a vehicle traveling at 55 mph, with the minimum distance corresponding to a three - second spacing between the primary vehicle 102 and the secondary vehicle 104. Each increase in feet represents an increase of one second in the time between the primary vehicle 102 and the secondary vehicle 104.

[0063] Table 3 FCW System Activation Thresholds for DAVs at 55 mph

[0064] DAV FCW System Activation Threshold (feet) 1.0 242 0.875 323 0.75 403 0.625 484 0.5 565 0.375 645 0.25 726 0.125 807 0.0 887

[0065] Table 4 below shows various FCW system activation thresholds for various DAVs, measured in the distance between the primary vehicle 102 and the secondary vehicle 104, for a vehicle traveling at 65 mph, with the minimum distance corresponding to a three - second spacing between the primary vehicle 102 and the secondary vehicle 104. Each increase in feet represents an increase of one second in the time between the primary vehicle 102 and the secondary vehicle 104.

[0066] Table 4 FCW System Activation Thresholds for DAVs at 65 mph

[0067]

[0068]

[0069] Table 5 below shows various FCW system activation thresholds for various DAVs, measured in the distance between the primary vehicle 102 and the secondary vehicle 104, for a vehicle traveling at 75 mph, with the minimum distance corresponding to a three - second spacing between the primary vehicle 102 and the secondary vehicle 104. Each increase in feet represents an increase of one second in the time between the primary vehicle 102 and the secondary vehicle 104.

[0070] Table 5 FCW System Activation Thresholds for DAVs at 75 mph

[0071] DAV FCW System Activation Threshold (feet) 1.0 330 0.875 440 0.75 550 0.625 660 0.5 770 0.375 880 0.25 990 0.125 1100 0.0 1210

[0072] Returning to the description of method 300, at step 310, method 300 includes activating a threshold of the FCW system to control the operation of the FCW system. The FCW system activation threshold can be used to control the operation of the FCW system as depicted in the method described below Figure 8 and described. After step 310, method 300 ends.

[0073] In another example, a driver attention value (DAV) is determined using the following algorithm. Figure 7 FIG. 700 is an example of a diagram showing a driver's gaze area, which uses an algorithm to determine a driver attention value (DAV). FIG. 700 includes a driver 702. B1 and B2 are gaze boundaries, which are the limits within which driver 702 should be looking. G1 and G2 are examples of the driver's gaze (G1 is a forward driver gaze and G2 is a lateral driver gaze). Θ1 is a first gaze angle measured between G1 and B2. Θ2 is a second gaze angle measured between G2 and B2. In this example, the driver attention value (DAV) is determined using the following formula.

[0074] A n = A (n-1) + (B – G) * K g * ΔT

[0075] Where:

[0076] 0.0 ≤ A n ≤ 1.0

[0077] Where:

[0078] A n = Attention score calculated for the current cycle

[0079] A (n-1) = Attention score for the previous cycle

[0080] B = Angle to the nearest boundary edge

[0081] G = Gaze angle

[0082] K g = Internal factor that converts deviation error to an attention score

[0083] ΔT = Time since the last attention calculation.

[0084] And where:

[0085] Kg = Constant + Modification amount (M)

[0086] M = Value determined by additional detection status (e.g., if the driver is asleep or detected as injured)

[0087] The above formula is based on the driver's gaze error measured from a predefined area. There can be multiple predefined areas in the cockpit. This method takes into account the dead zones that the driver can look at without being considered inattentive. Additionally, it explains the decrease in the driver's attention score over time due to the magnitude and length of the gaze error angle.

[0088] Now referring to Figure 8 , an example method for controlling vehicle operation based on the driver's attention value is illustrated, and it is generally designated as 800. The steps of method 800 can be performed by the distributed system 100 depicted in Figure 1 or the centralized system 200 depicted in Figure 2 . In the case of the distributed system 100, the steps of method 800 can be performed by the processor 114 of the internal monitoring system 110, the processor 124 of the advanced driver assistance system 112, or a combination thereof. On the other hand, in the case of the centralized system 200, the steps of method 800 can be performed by the processor 214.

[0089] As illustrated in Figure 8 , method 800 begins at step 802. At step 802, upon vehicle startup, method 800 includes setting the forward collision warning (FCW) activation threshold to a minimum safety value. The minimum safety value can include the distance between the primary vehicle 102 and the secondary vehicle 104 measured in feet for a specific speed. For example, at 55 mph, the minimum safety value can be 242 feet (corresponding to a three-second spacing between the primary vehicle 102 and the secondary vehicle 104). At 65 mph, the minimum safety value can be 286 feet (corresponding to a three-second spacing between the primary vehicle 102 and the secondary vehicle 104). At 75 mph, the minimum safety value can be 330 feet (corresponding to a three-second spacing between the primary vehicle 102 and the secondary vehicle 104). At step 804, method 800 includes setting the driver attention value (DAV) to a maximum value (e.g., 1.0), which corresponds to the minimum safety value of the FCW system activation threshold.

[0090] Moving to step 806, during vehicle operation, method 800 includes determining the driver attention value (DAV) via the internal monitoring system (IMS). In one example, the DAV can be determined as illustrated in the method shown in Figure 3 . In another embodiment, the DAV can be determined using the method associated with Figure 7Determined in conjunction with the above-described algorithm. At decision step 808, method 800 includes determining whether the DAV is reduced. If the DAV is not reduced, method 800 moves to step 810, and method 800 includes maintaining the FCW system activation threshold at the current value. Returning to decision step 808, if the DAV is reduced, method 800 proceeds to step 812, and method 800 includes increasing the FCW system activation threshold. For example, increasing the FCW system activation threshold can include increasing the safety distance between the primary vehicle 102 and the secondary vehicle 104 as shown in Table 3-5 above.

[0091] Method 800 proceeds from step 810 and step 812 to step 814, and includes monitoring the FCW system activation value, such as the distance between the primary vehicle 102 and the secondary vehicle 104. In one embodiment, the FCW system activation value can be monitored using external sensors 130, 230, which are placed at a forward position of the primary vehicle 102. The external sensors 130, 230 can use lidar or similar technology to determine the distance between the primary vehicle 102 and the secondary vehicle 104. Returning to the description of method 800, at decision step 816, method 800 includes determining whether the FCW system activation value is less than or equal to the current FCW system activation threshold. If so, method 800 moves to step 818, and includes activating the FCW systems 136, 236. For example, an audible signal can be emitted from the sound generators 140, 240, while a visual signal can be displayed on the displays 142, 242, or a combination of both can occur simultaneously or near-simultaneously. Method 800 continues from step 818 to decision step 820.

[0092] Returning to decision step 816, if the FCW system activation value is not less than or equal to the FCW system activation threshold (i.e., the FCW system activation value is greater than the FCW system activation), method 800 also moves to decision step 820. At decision step 820, method 800 includes determining whether the primary vehicle 102 is turned off. If so, method 800 ends. Otherwise, if the primary vehicle 102 remains on and in operation, method 800 proceeds to decision step 822, and method 800 includes determining whether the DAV is increased. If not, method 800 returns to decision step 808 and continues as described herein. Otherwise, at decision step 822, if the DAV is increased, method 800 proceeds to block 824, and includes reducing the FCW system activation threshold. Thereafter, method 800 returns to step 806 and continues as described herein.

[0093] Accordingly, among other things, the examples, aspects, and features herein provide systems and methods for determining a driver attention value and using the driver attention value to control vehicle operation (e.g., a forward collision warning system) based on the driver attention value.

Claims

1. A system for controlling a forward collision warning system based on a driver attention value, the system comprising: a plurality of sensors; and an electronic processor configured to: determine a driver's gaze angle using the plurality of sensors; determine a driver attention value based on the gaze angle; determine a forward collision warning system activation threshold based on the driver attention value; and selectively activate the forward collision warning system based on the forward collision warning system activation threshold.

2. The system according to claim 1, wherein the electronic processor is configured to: monitor a forward collision warning system activation value; and activate the forward collision warning system when the forward collision warning system activation value is less than the forward collision warning system activation threshold.

3. The system according to claim 1, wherein the gaze angle is measured between a longitudinal axis of the vehicle and the direction the driver is looking.

4. The system according to claim 1, wherein the plurality of sensors includes at least a time-of-flight camera having a view of the interior of the vehicle.

5. The system according to claim 4, wherein the time-of-flight camera determines the direction the driver is looking, the driver's head position, the driver's body position, or a combination thereof to determine the gaze angle.

6. The system according to claim 5, wherein the gaze angle is compared with a look-up table of pre-determined gaze angles to determine the driver attention value.

7. The system according to claim 6, wherein the driver attention value decreases as the gaze angle increases.

8. The system according to claim 6, wherein the driver attention value is compared with a look-up table of pre-determined driver attention values to determine the forward collision warning system activation threshold.

9. The system according to claim 6, wherein the forward collision warning system activation threshold increases as the driver attention value decreases.

10. A system for controlling a forward collision warning system based on a driver attention value, the system comprising: a plurality of sensors; and an electronic processor configured to: determine a driver attention value for a driver; modify a forward collision warning system activation threshold based on the driver attention value; and selectively activate the forward collision warning system based on the forward collision warning system activation threshold.

11. The system according to claim 10, wherein the driver attention value is at least partially based on the driver's gaze angle, and the gaze angle is determined based on the direction the driver is looking, the driver's head position, the driver's body position, or a combination thereof.

12. The system according to claim 11, wherein the plurality of sensors includes a time-of-flight camera, and the time-of-flight camera detects the direction the driver is looking, the driver's head position, the driver's body position, or a combination thereof.

13. The system according to claim 11, further comprising a memory coupled to the electronic processor, the memory including a first look-up table, the first look-up table including a plurality of predetermined gaze angles and a plurality of driver attention values, wherein each of the plurality of driver attention values is associated with a corresponding predetermined gaze angle.

14. The system according to claim 13, wherein the memory further includes a second look-up table, the second look-up table including a plurality of forward collision warning system activation thresholds and the plurality of driver attention values, wherein each forward collision warning system activation threshold is associated with a corresponding driver attention value.

15. A method for controlling a forward collision warning system based on driver attention values, the method comprising: Determining a driver attention value for a driver; Determining a forward collision warning system activation threshold based on the driver attention value; And Selectively activating the forward collision warning system based on the forward collision warning system activation threshold.

16. The method according to claim 15, further comprising: Monitoring a gaze position associated with the driver using a time-of-flight camera having a field of view inside the vehicle, the driver being located in the vehicle, wherein the gaze position is based on the direction the driver is looking, the driver's head position, the driver's body position, or a combination thereof.

17. The method according to claim 16, further comprising: Determining a gaze angle from the gaze position, wherein the gaze angle is measured between a gaze axis aligned with the driver's gaze position and a driving axis aligned with the longitudinal axis of the vehicle.

18. The method according to claim 17, further comprising: Comparing the gaze angle with a gaze angle look-up table to determine the driver attention value.

19. The method according to claim 18, further comprising: Comparing the driver attention value with a driver attention value look-up table to determine the forward collision warning system activation threshold.

20. The method according to claim 19, further comprising: Monitoring a forward collision warning system activation value; And Selectively activating the forward collision warning system when the forward collision warning system activation value is less than the forward collision warning system activation threshold.

Images