Assessment of driver attention

Abstract

Driver evaluation system for a vehicle, comprising: one or more controllers programmed to generate a parameter for display indicating the level of attention of a driver to driving the vehicle for a period of time based on a complement of a weighted average of a plurality of counts, at least some of which represent a number of interaction events between the driver and an infotainment system in the vehicle during the period of time, wherein the one or more controllers are further programmed to associate the parameter with geographic coordinates traversed by the vehicle during the period of time and, in response to a driver attention request including the geographic coordinates, to output the parameter.

Description

TECHNICAL FIELD

[0001] This disclosure relates to systems and methods for assessing a driver's concentration on the task of driving. BACKGROUND

[0002] Sophisticated automotive electronic devices can provide a variety of features and functions with which the driver can interact. Furthermore, the number of available portable computing and telecommunications devices, such as cell phones, tablets, and wearable devices, is increasing. As a result, these portable devices are more likely to be present in the vehicle. Excessive use of these electronic and portable devices while driving can distract the driver's attention from the road.

[0003] US 2010 / 0 033 333 A1 discloses a driver assessment system for a vehicle with at least one controller programmed to generate a parameter for display indicating the driver's attention level. US 2009 / 0 273 687 A1 also describes an attention detection system using gaze direction analysis. SUMMARY

[0004] According to the invention, a driver evaluation system for a vehicle according to claim 1, a driver evaluation method according to claim 7 and a vehicle according to claim 13 are proposed. Advantageous embodiments are specified in the dependent claims and the following description.

[0005] A driver evaluation system for a vehicle includes one or more controllers programmable to generate a parameter for display indicating a driver's level of attention to driving the vehicle for a period of time based on a complement of a weighted average of a plurality of counts. At least some of the counts represent a number of interactions between the driver and an infotainment system in the vehicle during the period of time. The one or more controllers are further programmed to associate the parameter with geographic coordinates traversed by the vehicle during the period of time and to output the parameter in response to a driver attention request including the geographic coordinates.

[0006] The one or more controllers may be further programmed to accumulate one of the counts such that, in response to an interaction event occurring, the one of the counts being greater than zero, and a count timer exceeding a predefined time limit, the count timer is decremented according to a difference between the count timer and a quotient of the predefined time limit and the one of the counts. The time period may be defined by a sliding window time period. The one or more controllers may be further programmed to record a value of the parameter for each of the time periods defining a drive cycle. At least one of the plurality of counts may represent a number of look-away events from a road during the time period. The look-away events may be based on a driver's eye gaze direction or head position.The infotainment system can be a cell phone, an instrument panel cluster, or a center stack console.

[0007] A driver evaluation method includes accumulating, by a controller, a count of driver inattention events such that, in response to an interaction event occurring and a count timer exceeding a limit, the count timer is decremented according to a difference between the count timer and a quotient of the limit and the count. The method also includes displaying a driver attention state value based on a complement of a weighted average including the count. The method may further include associating the driver attention state value with geographic coordinates and outputting the driver attention state value in response to a driver attention request including the geographic coordinates.The method may further include recording the driver attention state value for each of a plurality of time periods defining a drive cycle and displaying an average of at least some of the driver attention state values ​​after completion of the drive cycle. The method may further include wirelessly transmitting the driver attention state value externally. The driver inattention event count may represent a number of looking-away events from a road for a time period. The looking-away events may be based on a driver's eye gaze direction or head position.

[0008] A vehicle includes an interface and one or more controllers programmed to generate, in response to a driver attention request, a parameter for display via the interface indicating a driver's attention level to driving the vehicle for a selected time period based on a complement of a weighted average, having a value between zero and one, of a plurality of counts. At least some of the counts represent a number of interactions between the driver and an infotainment system in the vehicle during the selected time period.The one or more controllers may be further programmed to accumulate one of the counts such that, in response to an interaction event occurring, the one of the counts being greater than zero, and a value of a count timer exceeding a predefined time limit, the value is decremented according to a difference between the count timer and a quotient of the predefined time limit and the one of the counts. The selected time period may define a drive cycle. At least one of the plurality of counts may represent a number of look-away events from a road during the selected time period. The look-away events may be based on a driver's eye gaze direction or head position. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a block diagram of a driver attention evaluation system. The Fig. 2A and Fig. 2B shows curves representing driver inattention events over time and a corresponding count of these for a sliding window time period. Fig. Figure 3 shows a block diagram of an algorithm for counting driver inattention events. The Fig. 4A and Fig. 4B show curves representing driver inattention events over time and a corresponding count of these using the algorithm of Fig. 3 represent. Fig. Figure 5 shows a block diagram of a vehicle incorporating the driver attention evaluation system of Fig. 1 contains. DETAILED DESCRIPTION

[0009] Embodiments of the present disclosure are described herein. It should be understood, however, that the disclosed embodiments are merely examples, and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.As will be understood by those of ordinary skill in the art, various features illustrated and described with reference to any of the figures may be combined with features illustrated in one or more other figures to produce embodiments not explicitly illustrated or described. The combinations of illustrated features provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the disclosure may be desirable for particular applications or implementations.

[0010] Drivers have access to a variety of in-vehicle infotainment systems, such as center stack consoles, instrument clusters, mobile phones, wearable devices, etc. Extensive use of these devices while driving can reduce driver concentration and attention. Although various systems can provide alerts or delay the delivery of information based on the extent to which the driver interacts with infotainment systems, it may also be useful to provide a measure of overall driver attention. That is, it may be useful to measure the driver's level of attention to the task of driving over a given period of time (e.g., a drive cycle, a selected portion of a drive cycle, etc.).) as a function of the driver's overall interaction with available devices during that time period: high interaction would suggest low driver attention to the driving task, while low interaction would suggest high driver attention to the driving task. Numerical values, symbols, pictograms, etc., can be used to convey the driver's attention level.

[0011] Referring to Fig. 1, one or more processors 10 may implement a set of algorithms structured to generate a parameter representing the driver's attention level to the driving task. First, data regarding the driver's head position excursions, center stack interaction, instrument cluster interaction, interaction with connected onboard devices, etc., are collected via respective counting algorithms 12, 14, 16, 18. As an example, cameras in the vehicle may be used to track a driver's eye gaze direction or head position using known techniques.If the gaze or posture is judged to be directed away from the road for at least a predetermined period of time (for example, using known recursive signal processing techniques to determine gazes longer than a predetermined period of time), an accumulator value, PE, may be incremented. Similarly, if signals from a center stack console, an instrument panel cluster, an on-board device in communication with the vehicle, etc., indicate that the driver is engaged, respective accumulator values ​​CS, Cl, BD may be incremented.

[0012] Any number of techniques can be used to track the extent of interaction with the subsystems and devices mentioned above. For example, Fig. 2A represents a number of interactions with a given infotainment device over a time period of 55 seconds. A value of 1 indicates an interaction event such as touching a screen, turning a dial, dialing a cellphone, etc. And a value of 0 indicates the absence of an interaction event. Fig. Figure 2B shows a corresponding ring buffer count with a 12-second moving window. While the count result from the ring buffer is the true accumulated count for the 12-second moving window, a sampling rate of 50 Hz will require 600 data memory allocations.

[0013] Referring to Fig. 3, an alternative counting algorithm can be used that requires only two fixed-size registers: one for the count and one for a count timer. If an interaction event is detected in decision block 24, the count is incremented in step 26. If the count is greater than 0 in decision block 28, the algorithm proceeds to decision block 30. If the count timer is less than a predefined time limit, the count timer is incremented in step 32. The count is then output in step 34. The algorithm then returns to decision block 24.

[0014] Accordingly, after system initialization, the count timer remains at 0 until the first interaction event occurs—at which point the count timer begins to increment in value up to the predefined time limit. The predefined time limit effectively dictates the rate at which the count is decremented in the absence of further interaction events: the smaller the limit, the faster the decrement occurs; the larger the limit, the slower the decrement occurs. Consequently, the limit can be selected or tuned to achieve a desired decrement for a particular infotainment device.For example, the limit may be selected such that the count for interactions with a mobile device decays more slowly than compared to interactions with a radio volume control because interactions with the mobile device may be more distracting than interactions with the radio volume control, etc.

[0015] Returning to decision block 30, if the timer is greater than the limit, the timer is reduced in step 32 by a fraction of its value equal to the difference between the timer and the quotient of the limit and the count. Additionally, the count is decremented. The algorithm then proceeds to step 34.

[0016] Once the count timer reaches the limit, the value of the count stops increasing because each increment of the count that occurred in step 26 is then removed in step 36. In other words, once the count timer exceeds the limit, the value of the count will either remain the same (in the presence of interaction events) or decrease in value.

[0017] Returning to decision block 28, if the count is 0, the timer is reset to 0. The algorithm then returns to decision block 24.

[0018] Fig. Figure 4A again shows the number of interactions with the given infotainment device over a time period of 55 seconds. (The same number of interactions with the same frequency as Fig. 2A.) Fig. Figure 4B shows a corresponding count using the memory-efficient algorithm of Fig. 3. In comparison of the Fig. 2B and Fig. 4B, the memory-efficient algorithm approaches the count with a reasonable degree of accuracy, but with much less overhead.

[0019] Referring to Fig. 1, the respective counts PE, CS, CI, and BD are provided to an attention state aggregation algorithm 40. In one example, the respective counts are summed using a weighted average to generate an attention state aggregation value, ASA, according to the following equation ASA=∑i=1Nwiyi where N is the number of tracked driver interaction devices, y i indicates the accumulated occurrences of the interaction device and w iis the weight assigned to each device-verifiable dependent. The weights may be selected such that each resulting ASA has a value between 0 and 1. And the values ​​may be selected taking into account that certain interactions may be more distracting than others: dialing on a brought-along device (such as a cellphone) may be more distracting than turning a dial in an instrument cluster. Consequently, the rates at which the counts decay and the weights associated with the counts may be different in certain embodiments to reflect that certain types of interactions are more taxing than others.

[0020] Using the inputs PE, CS, CI and BD, the ASA would be given by ASA=PEwPE+CSwCS+ClwCl+BDwBD

[0021] However, any suitable aggregation technique may be used.

[0022] The ASA is then provided to a driver alertness state evaluation algorithm 42. In one example, the driver alertness state value, DASV, may be calculated as the complement of the ASA according to the following equation DASV=1−ASA

[0023] Consequently, the DASV provides a value between 0 and 1, which can be scaled as a percentile and classified into different categories to reflect driver attention for a given time period. Values ​​in the range of 80% to 100% may represent high driver attention to the driving task, while values ​​in the range of 0% to 20% may represent low driver attention to the driving task.

[0024] The respective counts discussed above may be collected at selected or periodic times, and equations (2) and (3) may be used to generate a DASV for that period. These DASVs may then, for example, be averaged to develop a DASV for a given drive cycle, or, for example, be associated with different geographical portions of a drive cycle so that driver alertness can be assessed for a city driving portion or a highway portion of the drive cycle. As an example, a DASV may be generated every minute, and each DASV may be associated with current geographical coordinates of the vehicle for that time. A user may then request the DASV for a particular portion of a drive cycle via a request for the DASV associated with geographical coordinates defined by the particular portion of the drive cycle.Values ​​for DASV or an average thereof can then be reported. Other scenarios are also being considered.

[0025] Referring to Fig.5, a vehicle 44 includes a variety of subsystems or devices with which a driver can interact, such as a center stack console 46 or an instrument panel cluster 48. A driver may also have a device 50, such as a cellphone or handheld device, brought into the vehicle 44 that communicates with various controls and communication infrastructure of the vehicle 44 using known techniques. Further, the vehicle 44 may include a camera system 51 configured, as known in the art, to track head movements or eye gaze directions of the driver. Data indicating whether the driver is interacting with any of the center stack console 46, the instrument panel cluster 48, or the brought device 50 may be provided to the driver attention assessment system 10 via a vehicle-area network or other communication lines therebetween.

[0026] Similarly, data representing the driver's head position or eye gaze direction may be provided to the driver attention assessment system 10. Using the algorithms described above, the processors of the driver attention assessment system 10 may generate the DASV from the provided data.

[0027] The DASV may be forwarded to a controller 52, which may selectively provide the DASV to an interface 54 for display, a memory 56 for later retrieval, or a transmitter (or other) for transmission outside.

[0028] The processes, methods, or algorithms disclosed herein may be applied to or implemented by a processing device, controller, or computer, which may include any existing programmable electronic control unit or dedicated electronic control unit. Likewise, the processes, methods, or algorithms may be stored as data and instructions executable by a controller or computer in many forms, including, but not limited to, information permanently stored on non-writable storage media such as ROM devices and information modifiably stored on writable storage media such as floppy disks, magnetic tapes, CDs, RAM devices, and other magnetic and optical media. The processes, methods, or algorithms may also be implemented in a software-executable object.Alternatively, the processes, methods, or algorithms may be embodied, in whole or in part, using suitable hardware components such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), state machines, controllers, or other hardware components or devices, or a combination of hardware, software, and firmware components.

[0029] The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. As previously described, the features of various embodiments may be combined to form other embodiments of the invention that may not be expressly described or illustrated. While various embodiments may have been described as providing advantages with respect to one or more desired features or as being preferred over other prior art embodiments or implementations, those of ordinary skill in the art will recognize that one or more features or characteristics may be compromised to achieve desired attributes of the overall system, depending on the specific application and implementation.These attributes may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, structure, size, maintainability, weight, manufacturability, ease of assembly, etc. Therefore, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.

Claims

[1] Driver evaluation system for a vehicle, comprising: one or more controllers programmed to generate a parameter for display indicating the level of attention of a driver to driving the vehicle for a period of time based on a complement of a weighted average of a plurality of counts, at least some of which represent a number of interaction events between the driver and an infotainment system in the vehicle during the period of time, wherein the one or more controllers are further programmed to associate the parameter with geographic coordinates traversed by the vehicle during the period of time and, in response to a driver attention request including the geographic coordinates, to output the parameter. [2] The system of claim 1, wherein the one or more controllers are further programmed to accumulate one of the counts such that, in response to an interaction event occurring, the one of the counts being greater than zero and a count timer exceeding a predefined time limit, the count timer is decremented according to a difference between the count timer and a quotient of the predefined time limit and the one of the counts. [3] The system of claim 1, wherein the one or more controllers are further programmed to record a value of the parameter for each of the time periods defining a drive cycle. [4] The system of claim 1, wherein at least one of the plurality of counts represents a number of look-away events from a road during the time period. [5] The system of claim 4, wherein the look-away events are based on a direction of the eyes or a head position of the driver. [6] The system of claim 1, wherein the infotainment system is a cellular phone, an instrument panel cluster, or a center stack console. [7] Driver assessment procedures, including: by a control Accumulating a count of driver inattention events such that, in response to an inattention event occurring and a count timer exceeding a limit, the count timer is decremented according to a difference between the count timer and a quotient of the limit and the count, and Displaying a driver attention state score based on a complement of a weighted average that includes the count. [8] The method of claim 7, further comprising associating the driver attention state value with geographic coordinates and outputting the driver attention state value in response to a driver attention request including the geographic coordinates. [9] The method of claim 7, further comprising recording the driver attention state value for each of a plurality of time periods defining a drive cycle and displaying an average of at least some of the driver attention state values ​​after completion of the drive cycle. [10] The method of claim 7, further comprising wirelessly transmitting the driver attention state value to an external location. [11] The method of claim 7, wherein the driver inattention event count represents a number of looking away events from a road for a period of time. [12] The method of claim 11, wherein the look-away events are based on a driver's eye gaze direction or head position. [13] Vehicle comprising: an interface; and one or more controllers programmed, in response to a driver attention request, to generate a parameter for display via the interface that indicates a driver's level of attention to driving the vehicle for a selected time period based on a complement of a weighted average, having a value between zero and one, of a plurality of counts, at least some of which represent a number of interaction events between the driver and an infotainment system in the vehicle during the selected time period, wherein the one or more controllers are further programmed to accumulate one of the counts such that, in response to an interaction event occurring, the one of the counts is greater than zero and a value of a count timer exceeds a predefined time limit,the value is reduced according to a difference between the counting timer and a quotient of the predefined time limit and one of the counts., [14] The vehicle of claim 13, wherein the selected time period defines a drive cycle. [15] The vehicle of claim 13, wherein at least one of the plurality of counts represents a number of look-away events from a road during the selected time period. [16] The vehicle of claim 15, wherein the look-away events are based on a direction of the eyes or a head position of the driver.

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