JP2005065861A - Cognitive load measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure accurate cognitive loads according to conditions of a person being a measuring object without burdening the person. <P>SOLUTION: At the time of calculating the cognitive loads required by the person being the measuring object to recognize an object, observing point coordinate data indicating the observing point coordinates of the person are calculated by an observing point detection part 11 and blinking data indicating the presence/absence of the blinking action of the measuring object person are calculated by a blinking state detection part 12. Then, in the cognitive load computing part 3, by a stop time data sorting part 25, stop time data indicating the time during which the observing point is stopped are calculated by using two or more pieces of observing point coordinate data, and the stop time data are sorted into the stop time data at the time of individual recognition in the case that the measuring object person recognizes an individual object and the stop time data at the time of space recognition in the case that the measuring object person recognizes a space structure on the basis of the blinking data. By a cognitive load index calculation part 30, the ratio of the stop time data at the time of the individual recognition and the stop time data at the time of the space recognition is obtained and the cognitive loads are calculated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cognitive load measuring device that measures a cognitive load required to recognize a surrounding object by, for example, a driver driving a vehicle.

  2. Description of the Related Art Conventionally, as a technique for measuring the cognitive load of a vehicle driver, an aptitude inspection device for an automobile driver described in Patent Document 1 below is known.

  The automobile driver aptitude checking device described in Patent Document 1 includes a switch corresponding to an accelerator pedal, a switch corresponding to a brake pedal, and a color display device. In this vehicle driver aptitude test device, when measuring the driver's recognition time and response time, the color display device is arranged in a random order, with random figures corresponding to red, yellow and blue traffic signals. Recognition at the time interval, recognition time from the time when the yellow signal is displayed until the time when the switch corresponding to the accelerator pedal is released, recognition until the time when the switch corresponding to the accelerator pedal is released from the time when the red signal is displayed The response time from the time when the switch corresponding to the accelerator pedal is released to the time when the switch corresponding to the brake pedal is operated is measured.

Next, this car driver aptitude test device calculates the average value, standard deviation, maximum value, variation index, etc. for each recognition time and response time after the measurement is completed. The driver's aptitude test was performed by calculating an index indicating the magnitude of the fluctuation tendency.
Patent No. 3100066

  However, in the above-described conventional aptitude test device for a driver of a car, a driver's recognition time and response time are calculated using a device that simulates a driving operation by performing a display corresponding to a traffic signal. The characteristics of the driver are obtained by using the variation of cognitive time and response time as an index of cognitive ability. Therefore, in the conventional car driver aptitude test device, the driver's cognitive ability is only measured on the driving simulator, and the driver's tension is different from that when actually driving on the road. There was a problem that the measured cognitive ability was different from the actual cognitive ability during driving.

  In addition, the driver's cognitive ability changes from moment to moment depending on the situation around the vehicle, but conventional car driver aptitude test devices recognize the driver's perception from data indicating changes in recognition time and response time. Even when judging fluctuations in capacity, there is a problem that the environment is different from that during actual driving.

  Furthermore, when applying the above-described conventional technology during actual driving, it is necessary to present a traffic signal on the display screen, and it is necessary to present a traffic signal for measuring the recognition time and response time during driving action. There was a problem of not becoming.

  Therefore, the present invention has been proposed in view of the above-described situation, and the cognitive load measurement capable of measuring an accurate cognitive load according to the situation of the measurement target person without imposing a load on the measurement target person. An object is to provide an apparatus.

  In the cognitive load measuring device according to the present invention, when calculating the cognitive load required for the measurement subject to recognize the object, the gaze point coordinate data indicating the gaze point coordinate of the measurement subject is calculated by the gazing point coordinate calculation means. The blink data indicating the presence or absence of the blink action of the measurement subject is calculated by the blink action calculating means. And in this cognitive load measuring device, the stop time data which shows the time when the gazing point has stopped is calculated using the plurality of gazing point coordinate data calculated by the gazing point coordinate calculating unit by the stop time calculating unit. Next, in the cognitive load measuring device, the measurement target person uses the cognitive load calculating means to calculate the stop time data calculated by the stop time calculating means based on the blink data calculated by the blink action calculating means. Are classified into the stop time data at the time of individual recognition when recognizing and the stop time data at the time of spatial recognition when the measurement subject recognizes the spatial structure, and the stop time data at the time of individual recognition and the time of spatial recognition The above-mentioned problem is solved by calculating the cognitive load using the stop time data.

  According to the cognitive load measuring device according to the present invention, the stop time data at the time of individual recognition and the stop time data at the time of spatial recognition are calculated from the gazing point coordinate data and the blink data, and based on the respective stop time data. Since the measurement subject's cognitive load is calculated, it is possible to measure the cognitive load in a non-contact manner with respect to the measurement subject, and the load on the measurement subject during measurement can be reduced. Therefore, according to this cognitive load measuring device, the measurement target person uses the characteristics of the eye state when recognizing a surrounding single object or when recognizing the spatial configuration without applying a load to the measurement target person. The cognitive load can be accurately measured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The present invention is applied to a cognitive load measuring device configured as shown in FIG. 1, for example.

[Principle for measuring cognitive load]
First, before explaining the configuration of the cognitive load measuring apparatus to which the present invention is applied, the principle for measuring the cognitive load when the measurement subject recognizes an object will be explained. Here, there are three types of blink actions of the measurement subject. In other words, a blink action is a blink when the subject's will is clearly involved, and when the blink is voluntarily closed or closed in accordance with a signal, or when an external reflex-induced stimulus is clear Reflexive blinking, which is a blink that closes the eyelid reflexively when it is surprised by sudden noise or light, etc. There are also spontaneous blinks that are not closely related to external reflex-induced stimuli and are deeply related to the perception and psychological state of the measurement subject.

  On the other hand, in the cognitive load measuring device to which the present invention is applied, attention is paid to the spontaneous blink that reflects the state of cognition and psychology among the three types of blink actions.

  The features of this spontaneous blink include (1) a decrease in the blink rate when attention and attention are directed to visual information, (2) an increase in the blink rate when awareness is directed to thinking activities, (3) There is a blink at the end of recognition judgment, and (4) an increase in the occurrence rate of cluster blinks during fatigue.

  That is, the present invention is applied to a cognitive load measuring device that measures the cognitive load by paying attention to the relationship between the gaze movement action and the blink action of the measurement subject as shown in FIG. And this cognitive load measuring device performs a gaze movement act by the relationship between the presence or absence of the blink action after the measurement subject gazes at the object and the presence or absence of the gaze movement act after the measurement subject gazes at the object. The state of gaze immediately before performing is divided.

  According to FIG. 1, when there is a blink action after gaze of an object and there is a gaze movement action after gaze, the gaze action is for recognizing the object itself, for example, a road sign It is a gaze act to read or recognize other cars or people. This is (3) of the above-mentioned spontaneous blink and corresponds to the blink action after recognizing the gaze target.

  In addition, when there is a blink action after gaze and there is no gaze movement action after gaze, the blink action frequency per unit time is high and the measurement subject's thinking load is high . This corresponds to (2) of the spontaneous blinks described above.

  In addition, when there is no blink action after gaze and there is no eye movement after gaze, the frequency of blink action per unit time is low, and attention and interest in the gaze object is high. is there. This corresponds to (1) of the spontaneous blinks described above.

  Furthermore, when there is no blink action after gaze of the object and there is gaze movement action after gaze, the gaze action is for recognizing the positional relationship (the whole space) of the object. This is (3) of the spontaneous blink described above, and corresponds to a state in which the recognition of the entire space is not completed by the line of sight movement during the recognition of the entire space.

  Among the spontaneous blinks, the feature (3) includes a characteristic that causes blinks at the end of recognition determination. That is, the probability that the measurement target person will blink immediately after the recognition of a certain target object is significantly increased. For example, after recognizing the contents of a road sign during driving or recognizing the characteristics of a person walking on the shoulder, the blink occurrence rate is high. This is considered to reset visual information in order to recognize another object after recognizing one object.

  In addition, when the object to be recognized by the measurement subject is not an individual single object but a relative position grasp (spatial configuration or spatial structure), the line of sight is moved to recognize the positional relationship of each object. However, blinking occurs when the positional relationship is grasped. From another viewpoint, the probability that a blink will occur until the positional relationship is grasped becomes low. For example, during the movement of the line of sight to grasp the shape of the road ahead or the action of grasping the position of the person on the shoulder, the measurement subject is recognized as one continuous object of the movement of the line of sight. Because it is going to happen, the incidence of blinking is low.

  Therefore, in this cognitive load measuring device, in order to measure the cognitive load, when there is no blink action after gaze of the object and there is gaze movement action after gaze, that is, among the spontaneous blinks described above ( The feature of 3) is that the recognition of the entire space is not completed by the line-of-sight movement during the recognition of the entire space. Here, in the cognitive load measuring device, as shown in FIG. 2, the eye-gaze occurrence frequency and the eye-gaze stop time T1 immediately before the blinking action occurs after the blinking eye movement without blinking is performed. Measure the relationship.

  In addition, as described above, the probability that a blink at the end of recognition determination occurs after a certain visual recognition target is recognized increases. Therefore, when there is a jumping eye movement with blinks from the stop state of the gazing point, the probability of recognizing a stationary object such as a road sign as a visual target is high, so the stop immediately before the jumping eye movement is performed. Time is considered to be the time used for recognition. However, the occurrence of blinking includes a stochastic element to the last. For this reason, in the cognitive load measuring device, the stop time is statistically processed, and the stop time with the highest frequency of the blink action is extracted as the cognitive load.

  Therefore, in this cognitive load measuring device, in order to measure the cognitive load, when there is a blink action after gaze and there is a gaze movement action after gaze, that is, among the spontaneous blinks described above ( The feature of the blink action after recognizing the gaze target object itself in 3) is used. Here, in the cognitive load measuring device, as shown in FIG. 2, the relationship between the blink occurrence frequency and the gazing point retention time T2 immediately before the jumping eye movement accompanied by the blink is measured. Thereby, in the cognitive load measuring device, the frequency with which the blink action occurs with respect to the time when the measurement target person gazes at the object is measured.

  In this cognitive load measuring device, the margin of cognitive load is calculated by calculating the ratio of the stop time between the stop time T1 at the time of space recognition and the stop time T2 at the time of individual object recognition. Here, the load of the measurement subject required for space recognition is different from the load of the measurement subject required for individual object recognition. That is, for a driver with a low cognitive ability and a high cognitive load, the load when the cognitive task with different difficulty is given is different, so that the stop time T1 at the time of space recognition and the stop time T2 at the time of individual object recognition And the ratio of the stop time becomes higher.

[Configuration of cognitive load measurement device]
Next, based on the principle for measuring the cognitive load as described above, the cognitive load when the measurement subject is driving the vehicle is measured to control the information display position visually recognized by the measurement subject. The cognitive load measuring device to be reflected will be described.

  As shown in FIG. 3, the cognitive load measuring device includes an eye state measuring unit 1 provided at a position where an eyeball portion of a measurement subject can be imaged, a vehicle speed sensor 2 connected to a vehicle driving portion, such as a vehicle instrument. A recognition load calculation unit 3, a navigation system 4, a display timing calculation unit 5, and a display device 6 provided at a position that can be viewed from a measurement target person.

  The eye state measurement unit 1 measures the gaze point position and the blink state of the driver who is the measurement target. The eye state measuring unit 1 performs infrared corneal reflection and image processing to measure a gazing point position and a blink state.

  As a result, the eye state measurement unit 1 creates gaze point coordinate data and blink data according to the time axis and sends the data to the cognitive load calculation unit 3. Note that the eye state measurement unit 1 may perform measurement processing separately on the gazing point coordinate data and the blink data, and only measures the line-of-sight movement signal and blinks when the line-of-sight movement signal reaches a predetermined value. The blink data may be extracted based on the determination of the state.

  Further, the vehicle speed sensor 2 creates vehicle speed data indicating whether or not the host vehicle is traveling, and sends the vehicle speed data to the cognitive load calculation unit 3.

  The cognitive load calculation unit 3 uses the gaze point coordinate data and blink data from the eye state measurement unit 1 and the vehicle speed data from the vehicle speed sensor 2 to calculate the cognitive load during driving of the measurement subject. The processing content of the cognitive load calculation unit 3 will be described later.

  The navigation system 4 calculates the current position of the vehicle on which the cognitive load measuring device is mounted, traffic condition information such as road traffic congestion, and travel guidance information for promoting travel on the recommended route. Then, the navigation system 4 sends traffic condition information and travel guidance information presented to the driver to the display timing calculation unit 5.

  The display timing calculation unit 5 displays each information display timing based on the cognitive load calculated by the cognitive load calculation unit 3 when displaying the traffic situation information and the travel guide information sent from the navigation system 4 on the display device 6. Is calculated. Specifically, when the measurement subject's cognitive load is high, the amount of information that can be recognized within a limited time is small in order to make the display content easily visible. In a situation where the amount of information to be presented is large, the display timing calculation unit 5 causes the display device 6 to display the display timing of information with a low priority order later than the display timing of information with a high priority order.

"Functional configuration of cognitive load calculation unit 3"
In such a cognitive load measuring device, the cognitive load calculation unit 3 has a functional configuration as shown in FIG.

  Here, the eye state measurement unit 1 includes, for example, an eye tracker system, and thus includes a gazing point detection unit 11 that generates gazing point coordinate data and a blink state detection unit 12 that generates blink data. ing.

  The cognitive load calculation unit 3 stores program data for calculating the cognitive load in a ROM (Read Only Memory) or the like (not shown), and the program data is executed by a CPU (Central Processing Unit), so that FIG. It has each part shown in. That is, the cognitive load calculation unit 3 includes a gaze point movement amount calculation unit 21 connected to the gaze point detection unit 11, a gaze point stop state determination unit 22, and a blink presence determination unit 23 connected to the blink state detection unit 12. A stop time calculation unit 24, a stop time data selection unit 25 connected to the vehicle speed sensor 2, an individual recognition stop time data storage unit 26, an individual recognition stop time data frequency distribution calculation unit 27, a space recognition stop time data storage unit 28, It has a space recognition stationary time data frequency distribution calculation unit 29 and a cognitive load index calculation unit 30.

  When a plurality of gazing point coordinate data that are temporally forward and backward are sent from the gazing point detection unit 11, the gazing point movement amount calculation unit 21 calculates data indicating the movement amount of each gazing point, and determines the gazing point stop state determination. Send to part 22. The data indicating the movement amount of each gazing point indicates the movement distance per unit time between the gazing point coordinate data.

  When the data indicating the movement amount of each gazing point is sent from the gazing point movement amount calculation unit 21, the gazing point stasis state determination unit 22 determines the stasis state between the gazing points. At this time, the gazing point stop state determination unit 22 normally moves each gazing point slightly when the measurement subject recognizes the visual recognition target, so that the gazing point suspending state determination unit 22 stops when the movement per unit time is a predetermined value or less. Judge that you are doing. Thereby, the gazing point stationary state determination unit 22 determines whether or not the gazing point is in the stationary state for each gazing point coordinate data. Then, the gazing point stop state determination unit 22 sends the gazing point coordinate data and the stop determination result to the blink presence / absence determination unit 23 and the stop time calculation unit 24.

  The blinking presence / absence determination unit 23 receives a plurality of blink data that are temporally moved from the blinking state detection unit 12 and the gazing point coordinate data is transmitted from the gazing point stop state determination unit 22. It is determined whether or not a blink action has occurred. Thereby, the blink presence / absence determination unit 23 extracts the gaze point coordinate data detected when the blink action occurs. Then, the blink presence / absence determination unit 23 sends the gazing point coordinate data when the blink action occurs and the gazing point coordinate data based on the line of sight movement not accompanied by the blink action to the stop time data selection unit 25 as a blink presence / absence determination result.

  When the stop determination result is sent from the gazing point stop state determination unit 22, the stop time calculation unit 24 counts up the stop time, for example, every predetermined sampling period. Thereby, the stop time calculation unit 24 creates stop time data in which the gazing point has stopped, and sends the stop time data to the stop time data selection unit 25.

  The stop time data selection unit 25 refers to the blink presence / absence determination result from the blink presence / absence determination unit 23 for the stop time data, and selects the stop time data in which the blink action occurs when the gazing point is displaced between the stop points. Then, the selected stop time data is sent to and stored in the individual recognition stop time data storage unit 26 as stop time data at the time of individual recognition.

  The individual recognition stationary time data frequency distribution calculation unit 27 calculates the frequency distribution of the stationary time during individual recognition using the stationary time data accumulated in the individual recognition stationary time data storage unit 26. Then, as shown in FIG. 2, the individual recognition stationary time data frequency distribution calculating unit 27 uses the stationary time T2 having the highest frequency of stationary time as a representative value, and the cognitive load as the cognitive load at the time of individual recognition of the measurement subject. The data is sent to the index calculation unit 30.

  In addition, the stop time data selection unit 25 refers to the blink presence / absence determination result from the blink presence / absence determination unit 23 for the stop time data, and the stop action in which no blink action occurs when the gazing point is displaced between the stop points. The time data is selected, and the selected stop time data is sent to and stored in the space recognition stop time data storage unit 28 as stop time data at the time of space recognition.

  The space recognition stop time data frequency distribution calculation unit 29 calculates the stop time frequency distribution during space recognition using the stop time data stored in the space recognition stop time data storage unit 28. Then, as shown in FIG. 2, the spatial recognition stationary time data frequency distribution calculating unit 29 uses the stationary time T1 having the highest frequency of stationary time as a representative value, and the cognitive load as the cognitive load at the time of spatial recognition of the measurement subject. The data is sent to the index calculation unit 30.

  The cognitive load index calculation unit 30 obtains a ratio between the stop time T1 and the stop time T2, creates cognitive load index information indicating that the cognitive load of the measurement target person is higher as the ratio is higher, and displays the display timing. The result is sent to the calculation unit 5.

[Cognitive load calculation processing by cognitive load measurement device]
Next, a processing procedure for calculating the cognitive load during driving of the measurement target person using the cognitive load measuring apparatus configured as described above will be described with reference to the flowchart of FIG.

  First, in the cognitive load calculation unit 3, for example, after an IGN switch of a vehicle is operated and activated, in step S1, a value of a stop flag indicating whether or not the gazing point is stopped and whether blinks have occurred. Initialization is performed by setting both the values of the blink flag indicating whether or not to “0”, for example.

  Next, in step S2, the cognitive load calculation unit 3 starts counting up a timer that measures a predetermined sampling period. In step S3, the gaze point of the gaze point coordinate (n) acquired by the gaze point detection unit 11 is started. The coordinate data and blink data acquired by the blink state detection unit 12 are read. In this cognitive load calculation process, the timer counts up in a predetermined sampling period by executing the processes in steps S2 to S27 within a predetermined sampling period set in advance.

  In the next step S4, the blink presence / absence determining unit 23 determines whether or not a blink action has occurred at time n based on the blink data read in step S3. Here, the blink presence / absence determination unit 23 proceeds to step S14 when it is determined that the blink action has occurred, and proceeds to step S5 when it is determined that the blink action has not occurred. .

  In step S5, the gazing point movement amount calculation unit 21 acquires the gazing point coordinates (n-1) of the gazing point coordinate data acquired at the previous time (time n-1) and the current time (time n) in step S3. The moving distance of the gazing point coordinate data from the gazing point coordinate (n) is calculated, and the moving speed of the gazing point is calculated.

  In the next step S6, whether or not the gazing point is stopped is determined by determining whether or not the moving speed of the gazing point calculated in step S5 is equal to or less than a predetermined value by the gazing point stopping state determination unit 22. judge. Here, the gazing point stationary state determination unit 22 determines whether or not the gazing point is in the stationary state by determining whether or not the moving amount of the gazing point in the predetermined sampling period is small and the moving speed is equal to or less than a predetermined value. It is determined whether the eye movement is a jumping eye movement. If the gaze point stop state determination unit 22 determines that the gaze point is not stopped, the gaze point stop state determination unit 22 determines that the visual target of the measurement target person has shifted to another object, and proceeds to step S16. If it is determined that the viewpoint is stationary, the process proceeds to step S7. In other words, the gazing point stationary state determination unit 22 determines whether or not the movement of the gazing point is within a predetermined coordinate range.

  In step S7, the value of the stop flag (n) at time n is set to “1” in response to the determination that the watch point is stopped in step S6 by the watch point stop state determination unit 22. To the stop time calculation unit 24.

  Next, the stop time calculation unit 24 counts up the gazing point coordinate data numbers for identifying a plurality of gazing point coordinate data different in time in step S8, and the gazing point coordinates stored in step S8 in step S9. Among the data, the number of gazing point coordinate data being stopped is counted up.

  In the next step S10, the time counted up in step S2 by the individual recognition stationary time data frequency distribution calculating unit 27 and the spatial recognition stationary time data frequency distribution calculating unit 29 is to obtain a preset cognitive load. By determining whether or not it is a multiple of the set time, it is determined whether or not the predetermined time interval for calculating the cognitive load. When the individual recognition stationary time data frequency distribution calculating unit 27 and the spatial recognition stationary time data frequency distribution calculating unit 29 determine that the predetermined time interval for calculating the cognitive load is not reached, the process returns to step S2. If it is determined that it is a predetermined time interval for calculating the cognitive load, the process proceeds to step S11.

  In step S11, the space recognition stop time data frequency distribution calculation unit 29 stores the stop time data accumulated in the predetermined time interval determined in step S10 from the space recognition stop time data storage unit 28. The frequency distribution of the stop time indicated by the read and stop time data is obtained, and the stop time T1 as a representative value is calculated and sent to the cognitive load index calculating unit 30.

  In step S12, the individual recognition stop time data frequency distribution calculation unit 27 stores the stop time data accumulated in the predetermined time interval determined in step S10 from the individual recognition stop time data storage unit 26. The frequency distribution of the stop time indicated by the read and stop time data is obtained, and the stop time T2 as a representative value is calculated and sent to the cognitive load index calculating unit 30.

  In step S13, the cognitive load index calculation unit 30 obtains a ratio between the stop time T1 at the time of spatial recognition obtained at step S11 and the stop time T2 at the time of individual recognition obtained at step S12, and calculates the ratio. The measurement target person's cognitive load index information is sent to the display timing calculation unit 5, and the process returns to step S2. In step S13, after generating the cognitive load index information, the stop time data stored in the individual recognition stop time data storage unit 26 and the space recognition stop time data storage unit 28 is cleared.

  On the other hand, in step S14 after determining that the blink action has occurred in step S4, the blink action occurred during the calculation of the Nth stop point coordinate at time n by the blink presence / absence determining unit 23. Is set to “1” and sent to the stop time data selection unit 25. In step S15, the stop time data selection unit 25 sets the stop flag (n− at time n−1). By determining whether or not the value of 1) is “1”, it is determined whether or not the blink action determined in step S4 is a blink action immediately after the gazing point stops.

  If the stop time data selection unit 25 determines that it is a blink action immediately after the gazing point stops, the process proceeds to step S18 and subsequent steps for obtaining the stop time data, and immediately after the gazing point stops. If it is determined that it is not a blink action, the process proceeds to step S10.

  Also, in step S16 after determining that the moving speed of the gazing point is not less than or equal to the predetermined value in step S6, the gazing point stopping state determination unit 22 sets the value of the stop flag (n) at time n to “0”. In step S17, it is determined whether or not the value of the stop flag (n-1) at time n-1 is "1". It is determined whether or not it is an immediate gaze movement act. Then, when it is determined that the gaze point stopping state determination unit 22 is the gaze movement act immediately after the gaze point is stopped, the process proceeds to step S18, and it is determined that the gaze point stop state determination unit 22 is not the gaze shift act immediately after the gaze point is stopped In that case, the process proceeds to step S10.

  In step S18, the stopping time data sorting unit 25 calls the number of data counted as the gazing point coordinate data during stopping in step S9.

  In the next step S19, the stationary time data selection unit 25 performs the stationary average by taking the coordinate average using the gazing point coordinate data within the same predetermined coordinate range as the gazing point coordinate data (n) acquired in step S3. The point coordinate data is calculated and the data number N of the stop point coordinate data is counted up.

  In the next step S20, the stop time data selection unit 25 multiplies the number of data of the gazing point coordinate data acquired during the stop read in step S18 by the predetermined sampling period counted up in step S2. The stop time data indicating the stop time (N) is calculated and stored temporarily.

  In the next step S21, the stop time data sorting unit 25 resets the blink flag (N) by setting it to “0”, and in step S22, the stop time data is calculated in step S20. Clears the data indicating the number of gazing point coordinate data used.

  In the next step S23, the stop time data selection unit 25 reads the vehicle speed detected by the vehicle speed sensor 2 to determine whether or not the vehicle is currently traveling. The stop time data selection unit 25 proceeds to step S10 when it is determined that the vehicle is not currently traveling, and proceeds to step S24 when it is determined that the vehicle is currently traveling.

  In step S24, the stored stop time (N-1) at time n-1 is read by the stop time data selection unit 25. In step S25, the value of the blink flag at time n-1 is read. Is determined to be “1”.

  If the stop time data selection unit 25 determines that the value of the blink flag (N−1) is not “1”, the stop time (N−1) is determined as the stop time during space recognition in step S27. The data is stored in the space recognition stop time data storage unit 28 as data. On the other hand, if the stop time data selection unit 25 determines that the value of the blink flag (N-1) is “1”, the stop time data read in step S24 is the stop time data at the time of individual recognition. Is stored in the individual recognition stopping time data storage unit 26, and the process proceeds to step S10.

  As a result, the stop time data selection unit 25 accumulates the stop time data acquired immediately before the blink action occurs at the time of eye movement in the individual recognition stop time data storage unit 26 as the stop time data at the time of individual recognition, and moves the eye movement. Sometimes the stop time data acquired when the blink action has not occurred is accumulated in the space recognition stop time data storage unit 28 as stop time data at the time of space recognition. And in a cognitive load measuring device, the process which accumulate | stores dwell time data is repeated until it becomes the predetermined | prescribed time interval which calculates cognitive load in step S10.

  In the cognitive load measurement device that performs such cognitive load calculation processing, the blinking immediately after the gazing point stops and the gaze movement immediately after the gazing point stops are detected. And the cognitive load can be obtained by obtaining the frequency distribution of the suspension times T1 and T2 as shown in FIG.

[Effect of the embodiment]
As described above in detail, according to the cognitive load measuring device to which the present invention is applied, the cognitive load (T2) for recognizing a single object and the spatial configuration are recognized from the gaze point coordinate data and the blink data. To calculate the cognitive load (T1), and to calculate the cognitive load of the measurement target person based on the ratio of the cognitive load, enabling the measurement target person to measure the cognitive load without contact, The load on the measurement subject at the time of measurement can be reduced. Therefore, according to this cognitive load measuring device, the measurement target person uses the characteristics of the eye state when recognizing a surrounding single object or when recognizing the spatial configuration without applying a load to the measurement target person. The cognitive load can be accurately measured.

  In addition, according to this cognitive load measuring device, the stop time immediately before the blink action occurs when the line of sight is moved is set as the stop time at the individual recognition, and the stop time immediately before the blink action is not generated when the line of sight is moved is a space. Since the cognitive load can be calculated by selecting the stop time at the time of recognition, the cognitive load according to the situation at the time of driving can be calculated using the characteristics of the driver's eyes.

  Furthermore, according to this cognitive load measuring device, the stop time at the time of individual recognition is accumulated to obtain the frequency distribution of the stop time, and the stop time at the time of spatial recognition is accumulated to obtain the frequency distribution of the stop time. The cognitive load can be reliably measured based on the representative value of the stop time.

  Furthermore, according to this cognitive load measuring device, it is possible to measure the cognitive load during driving without imposing a load on the measurement subject, and by controlling the display timing according to the cognitive load of the measurement subject, The load for visually recognizing the display content displayed on the object and the display device 6 can be reduced, and drivability can be improved. In particular, according to this cognitive load measuring device, an appropriate display timing can be adjusted in the case of a driver whose cognitive load tends to be longer than that of a young person such as an elderly driver.

  Furthermore, according to this cognitive load measuring device, when the cognitive load of the measurement subject is high in a situation where the amount of information presented by the navigation system 4 such as an intersection is large, the display timing of information with low priority is set. Since the information is displayed on the display device 6 later than the display timing of the information with high priority, driving is performed without causing the display device 6 to display information when the load of the vehicle driver recognizing an object in the outside world is high. The driving performance of the person can be improved.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and various modifications can be made depending on the design and the like as long as the technical idea according to the present invention is not deviated from this embodiment. Of course, it is possible to change.

It is a figure for demonstrating the principle which calculates cognitive load in the cognitive load measuring device to which this invention is applied. It is a figure for demonstrating the frequency distribution of the stationary time acquired when calculating the cognitive load in the cognitive load measuring device to which this invention is applied. It is a block diagram which shows the structure of the cognitive load measuring device to which this invention is applied. It is a block diagram which shows the functional structure of the cognitive load calculating part of the cognitive load measuring device to which this invention is applied. It is a flowchart which shows the process sequence when measuring cognitive load in the cognitive load measuring device to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Eye state measurement part 2 Vehicle speed sensor 3 Cognitive load calculation part 4 Navigation system 5 Display timing calculation part 6 Display apparatus 11 Gaze point detection part 12 Blink state detection part 21 Gaze point movement amount calculation part 22 Gaze point stop state determination part 23 Blink presence / absence determination unit 24 Stop time calculation unit 25 Stop time data selection unit 26 Individual recognition stop time data storage unit 27 Individual recognition stop time data frequency distribution calculation unit 28 Spatial recognition stop time data storage unit 29 Spatial recognition stop time data frequency distribution Calculation unit 30 Cognitive load index calculation unit

Claims (6)

Gazing point coordinate calculating means for calculating gazing point coordinate data indicating the gazing point coordinates of the measurement subject;
Blink action calculating means for calculating blink data indicating the presence or absence of the blink action of the measurement subject;
Using a plurality of gazing point coordinate data calculated by the gazing point coordinate calculation unit, stopping time calculation unit for calculating the stopping time data indicating the time when the gazing point is stopped;
Based on the blink data calculated by the blink action calculating means, the stopping time data calculated by the stopping time calculating means is used as the stopping time data at the time of individual recognition when the measurement subject recognizes an individual object. And the stop time data at the time of spatial recognition when the measurement target person recognizes the spatial structure, and using the stop time data at the time of the individual recognition and the stop time data at the time of the spatial recognition, A cognitive load measuring device comprising: cognitive load calculating means for calculating a cognitive load required for the object to recognize an object.   The cognitive load calculating means, when a blink action occurs at the time of gaze movement after the gazing point stops, the suspending time data indicating the suspending time when the gazing point is stopped as the stopping time data at the time of individual recognition If there is no blinking action when moving the line of sight after the gazing point stops, the suspending time data indicating the suspending time when the gazing point has stopped is selected as the suspending time data at the time of spatial recognition. The cognitive load measuring device according to claim 1.   The cognitive load calculating means calculates a stop time frequency distribution indicated by the stop time data at the time of individual recognition and calculates a stop time having the highest frequency as a representative value of the stop time at the time of individual recognition, and the space The cognitive load according to claim 1, wherein a frequency distribution of stop times indicated by stop time data at the time of recognition is calculated and a stop time having the highest frequency is calculated as a representative value of the stop time at the time of space recognition. Measuring device.   The cognitive load calculating means obtains the ratio of the stop time between the representative value of the stop time at the time of the individual recognition and the representative value of the stop time at the time of the space recognition, and uses the ratio as the cognitive load. The cognitive load measuring device according to claim 3. Vehicle travel state determination means for determining whether or not the vehicle is traveling,
The cognitive load calculation means calculates the cognitive load when the vehicle running state determination means determines that the vehicle is running. The recognition according to any one of claims 1 to 4, Load measuring device.   6. The cognitive load according to claim 1, further comprising display control means for controlling a display timing for displaying information based on the cognitive load calculated by the cognitive load calculating means. Measuring device.

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