JP2008250406A - Aged driver support system, driving age determination method and driving age determination program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aged driver support system, which notifies an aged driver of the impaired driving technique by comparing a steering smoothness index which is significantly different between an aged driver and a young driver with a preset threshold and giving a warning to a driver with low smoothness. <P>SOLUTION: In this aged driver support system, angular velocity data is obtained by time-differentiating a steering angle signal of a steering angle sensor 4, an angular velocity data group belonging to a period between an entry point and an exit point of a corner is Fourier-transformed, an energy distribution on frequency axis is calculated by squaring the converted value, a steering smoothness index R is determined from the energy distribution, and compared with a safe driving index threshold Ref 2, and a warning is outputted when the steering smoothness index exceeds the safe driving index threshold. According to this, an aged driver is warned to recognize that he or she does not smoothly steer the vehicle at a corner, which is remarkable to the aged driver. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an elderly driver support system, a driving age determination method, and a driving age determination program for raising the attention of a driver with low smoothness of steering at a turning angle, and in particular for promoting awareness of a decrease in driving skill of an elderly driver.

  Conventionally, as a technique for monitoring the driving operation status of a driver, a technique for paying attention to the steering angle, performing frequency analysis after Fourier transforming the steering angle data, and determining the driving operation status based on the analysis result is disclosed in Japanese Patent Application Laid-Open No. Hei 9-2009. Those described in Japanese Patent No. 277848 (Patent Document 1) and those described in Japanese Patent Laid-Open No. 5-58192 (Patent Document 2) are known. Japanese Patent Application Laid-Open No. 2001-253266 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2003-246227 (Patent Document 4) also describe a technique for determining the driving ability of a driver.

  However, none of these conventional techniques pay attention to the smoothness of the steering at the corner of the road.

  With the arrival of an aging society in recent years, older drivers are also increasing. Along with the decline in athletic ability, elderly drivers tend to cause delays in braking due to dull reflexes and oversight of road traffic signs, but at the same time, the smoothness of driving tends to decrease. This decrease in smoothness of the driving operation, that is, “the awkwardness of the driving operation” appears particularly remarkably in the awkwardness of the steering at the corner.

  The inventors of the present application asked 20 drivers of 30-45-year-olds and 80 drivers of 65-year-olds or older to drive on ordinary roads in their regular cars. I collected and analyzed the steering angle data of each driver at that time. Then, the differential value of the steering angle at the turning angle, that is, the angular velocity was Fourier transformed, and the energy distribution of the squared angular velocity was found to have a significant difference depending on the age group.

FIG. 9 shows a map of the traveling course. In this traveling course, the steering angle data at the corners C2, C3, C6, C7, and C9 are sampled, the angular velocity data is calculated by the time differentiation, Fourier-transformed, and squared to obtain FIG. A frequency versus energy distribution as shown in FIG. FIG. 10 shows the result of a single driver of a middle age group, and FIG. Then, the threshold value is set to a frequency of 0.5 / sec, and the ratio of the integral value of the high region above the threshold value of 0.5 / sec to the integral value of the entire frequency region (here, the steering smoothness index, or (Referred to as C index), and the average of the smoothness indices at five bends for each driver. As a result, the distribution shown in FIG. 12 was obtained. And when Welch's T test was performed on this distribution, a significant difference (P <0.0001) was recognized between the elderly driver and the elderly driver.
Japanese Patent Laid-Open No. 9-277848 JP-A-5-58192 JP 2001-253266 A JP 2003-246227 A

  The present invention was made on the basis of the above experimental results, and compared the steering smoothness index, which shows a significant difference between the elderly driver and the younger driver, with a preset threshold value. An object of the present invention is to provide an elderly driver support system, a driving age determination method, and a driving age determination program that make a driver aware of a decrease in driving skill by issuing a warning to a low driver (high C index).

  One feature of the present invention is a turning angle determination means for determining a turning angle on a road, a steering angle sensor that detects a steering angle of a steering wheel and outputs it at a first predetermined cycle, and a steering angle signal of the steering angle sensor. The angular velocity calculation means for obtaining the angular velocity data by time differentiation, and the Fourier velocity of the angular velocity data group belonging to the period from the entry point to the departure point of the bending angle determined by the bending angle determination means, and squaring the converted value A Fourier transform means for calculating an energy distribution on the frequency axis, and an integral value (high-range integral value) of a value in a frequency region higher than a predetermined frequency threshold among the energy distribution calculated by the Fourier transform means And an integration means for obtaining an integral value (a whole area integral value) of values in the entire frequency region of the angular velocity Fourier transform value, and a ratio of the high area integral value obtained by the integration means to the whole area integral value The steering smoothness index calculating means obtained as the steering smoothness index and the steering smoothness index obtained by the steering smoothness index calculating means are compared with a safe driving index threshold value, and the steering smoothness index is a threshold value for the safe driving index. An elderly driver support system comprising driving age determination means for outputting a warning when a value is exceeded.

  Another feature of the present invention is a turning angle determination means for determining a turning angle on a road, a steering angle sensor that detects a steering angle of a steering wheel and outputs it at a first predetermined cycle, and a steering angle signal of the steering angle sensor. The angular velocity calculation means for obtaining the angular velocity data by time differentiation, and the Fourier velocity of the angular velocity data group belonging to the period from the entry point to the departure point of the bending angle determined by the bending angle determination means, and squaring the converted value A Fourier transform means for calculating an energy distribution on the frequency axis, and an integral value (high-range integral value) of a value in a frequency region higher than a predetermined frequency threshold among the energy distribution calculated by the Fourier transform means And an integration means for obtaining an integral value (a whole area integral value) of values in the entire frequency region of the angular velocity Fourier transform value, and steering a ratio between the high area integral value and the whole area integral value obtained by the integration means Steering smoothness index calculating means obtained as a smoothness index, correspondence table means of steering smoothness index and driving age index, and steering smoothness index obtained by the steering smoothness index calculating means with reference to the correspondence table means This is an elderly driver support system provided with driving age determination means for converting to a driving age index.

  Another feature of the present invention is a turning angle determination step for determining a turning angle on a road, an angular velocity calculation step for obtaining angular velocity data by time-differentiating a steering angle signal of a steering angle sensor, and a turning angle determined in the turning angle determination step. Fourier transform step of calculating the energy distribution on the frequency axis by Fourier transforming the angular velocity data group belonging to the period from the entry point to the exit point, and calculating the energy distribution on the frequency axis. Among the energy distributions, an integral value (high-frequency integral value) of a frequency region value higher than a predetermined frequency threshold value, an integral value (global integral value) of all frequency region values of the angular velocity Fourier transform value, and And a steering smoothness index calculation step for determining, as a steering smoothness index, a ratio of the high-frequency integrated value determined in the integration step to the total integrated value. Driving age determination step of comparing the steering smoothness index obtained in the steering smoothness index calculation step with a safe driving index threshold and outputting a warning when the steering smoothness index exceeds the safe driving index threshold And a driving age determination method.

  Another feature of the present invention is a turning angle determination step for determining a turning angle on a road, an angular velocity calculation step for obtaining angular velocity data by time-differentiating a steering angle signal of a steering angle sensor, and a turning angle determined in the turning angle determination step. Fourier transform step of calculating the energy distribution on the frequency axis by Fourier transforming the angular velocity data group belonging to the period from the entry point to the exit point, and calculating the energy distribution on the frequency axis. Among the energy distributions, an integral value (high-frequency integral value) of a frequency region value higher than a predetermined frequency threshold value, an integral value (global integral value) of all frequency region values of the angular velocity Fourier transform value, and And a steering smoothness index calculation step for determining, as a steering smoothness index, a ratio of the high-frequency integrated value determined in the integration step to the total integrated value. And a driving age determination step of referring to a correspondence table between the steering smoothness index and the driving age index and converting the steering smoothness index obtained in the steering smoothness index calculating step into a driving age index and outputting it. This is a determination method.

  Another feature of the present invention is a turning angle determination step for determining a turning angle on a road, an angular velocity calculation step for obtaining angular velocity data by time-differentiating a steering angle signal of a steering angle sensor, and a turning angle determined in the turning angle determination step. Fourier transform step of calculating the energy distribution on the frequency axis by Fourier transforming the angular velocity data group belonging to the period from the entry point to the exit point, and calculating the energy distribution on the frequency axis. Among the energy distributions, an integral value (high-frequency integral value) of a frequency region value higher than a predetermined frequency threshold value, an integral value (global integral value) of all frequency region values of the angular velocity Fourier transform value, and And a steering smoothness index calculation step for determining, as a steering smoothness index, a ratio of the high-frequency integrated value determined in the integration step to the total integrated value. Driving age determination step of comparing the steering smoothness index obtained in the steering smoothness index calculation step with a safe driving index threshold and outputting a warning when the steering smoothness index exceeds the safe driving index threshold Is a driving age determination program that causes a computer to execute.

  Still another feature of the present invention is that a turning angle determination step for determining a turning angle on a road, an angular velocity calculation step for obtaining angular velocity data by time-differentiating a steering angle signal of a steering angle sensor, and a turning angle determined in the turning angle determination step. Fourier transform step of calculating the energy distribution on the frequency axis by Fourier transforming the angular velocity data group belonging to the period from the entry point to the exit point, and calculating the energy distribution on the frequency axis. Among the energy distributions, an integral value (high-frequency integral value) of a frequency region value higher than a predetermined frequency threshold value, an integral value (global integral value) of all frequency region values of the angular velocity Fourier transform value, and And a steering smoothness index calculation step for determining, as a steering smoothness index, a ratio of the high-frequency integrated value determined in the integrating step to the total integrated value. And a driving age determination step of converting the steering smoothness index obtained in the steering smoothness index calculation step into a driving age index and outputting the result by referring to a correspondence table between the steering smoothness index and the driving age index This is a driving age determination program to be executed.

  In each of the above inventions, it can be determined that the point detected by the GPS corresponds to a turn on the road map.

  In each of the above inventions, a turn angle is determined when the integral value of the steering angle during a period in which the acceleration sensor detects acceleration equal to or higher than a predetermined threshold value becomes an angle equal to or higher than the predetermined threshold value. be able to.

  In each of the above inventions, the predetermined threshold value determined as the high-frequency integral value can be set to 0.5 / sec.

  Furthermore, in each of the above inventions, the safe driving index threshold value can be set to a value within the range of 0.10 to 0.25.

  According to the present invention, the angular velocity data is obtained by time differentiation of the steering angle signal of the steering angle sensor, the angular velocity data group belonging to the period from the entry point to the departure point of the turning angle is Fourier-transformed, and the converted value is 2 To calculate the energy distribution on the frequency axis, find the steering smoothness index from this energy distribution, compare with the safe driving index threshold, and when the steering smoothness index exceeds the safe driving index threshold Since the warning is output, it is possible to warn the elderly driver that the awkward steering appears at a turning angle as a prominent index, and to make the driver's age decline.

  Further, according to the present invention, the angular velocity data is obtained by differentiating the steering angle signal of the steering angle sensor with respect to time, the angular velocity data group belonging to the period from the turning point to the turning point is Fourier transformed, and the converted value Is squared to calculate the energy distribution on the frequency axis, a steering smoothness index is obtained from this energy distribution, and the steering smoothness index is converted into a driving age index and output with reference to the correspondence table. It is possible to present his / her driving age, and in particular, an elderly driver can be aware of a decline in driving age.

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

  (First Embodiment) An aged driver support system according to a first embodiment of the present invention will be described. As shown in FIG. 1, the elderly driver support system of the present embodiment is attached to a wheel shaft 2 of a steering wheel 1 and is installed at an appropriate position of a vehicle, a steering angle sensor 3 that detects an instantaneous value of the steering angle of the steering wheel 1. The GPS sensor 4, the steering angle detection data of the steering angle sensor 3 and the point detection data of the GPS sensor 4 are sampled at regular intervals and stored in time series, and the data stored in the data storage 5 is stored in the data storage 5. A driving age determination unit 6 that analyzes by a method to be described later, determines the steering smoothness, and outputs a warning, and an output device 7 such as a display that outputs a warning, a buzzer, and a printer. The data storage 5, the driving age determination unit 6, and the output device 7 can be configured by a personal computer in which a program for executing arithmetic processing described later is installed and a peripheral device connected thereto.

  The calculation processing method and calculation processing program executed by the driving age determination unit 6 will be described with reference to the block diagram of FIG. 2 and the flowchart of FIG. When the driver operates the steering wheel 1, the steering angle sensor 3 detects the rotation angle of the wheel shaft 2 as a steering angle and outputs it to the data storage 5. The data storage 5 chronologically stores the steering angle data at a predetermined sampling period. To accumulate. In parallel with the storage of the steering angle data, the GPS sensor 4 outputs the point detection signal to the data storage 5, and the data storage 5 accumulates the steering angle data in time series at a predetermined sampling period.

  After traveling a certain distance, the driving age determination unit 6 calculates a steering smoothness index at a turning angle using time-series steering angle data and point data stored in the data storage 5. This is according to the following procedure.

  Step S1: A digital value is output at a period of 1/20 sec by the steering angle sensor 3 mounted on the shaft 2 portion of the steering wheel 1.

  Steps S <b> 2 and S <b> 3: The moving average calculator 11 obtains a moving average with the number of samples of about 3 and stores it in the data storage 5 in time series. This is intended to eliminate components that are not intended by humans. If it is necessary to simplify the system, the processing functions of steps S2 and S3 can be omitted. Next, the resampling unit 11 performs resampling at a period of 1/10 sec.

  Step S4: The attenuator 13 is arranged so that it is not necessary to calibrate the zero point of the steering angle sensor 3 with respect to the steering angle data fetched from the data storage 5 at the time of starting the system (so that it is not necessary to place the steering wheel in place). Damping the output value moderately over time. This function is implemented as software. As a result, a mechanical error in the attachment of the handle and a deviation in the attachment position of the angle sensor can be allowed. However, if the attenuation coefficient is too large, there is an adverse effect such as an error in the measurement of the timing of returning the handle, so the coefficient is set to “weak”.

  Step S <b> 5: At each sampling timing, the differencer 14 takes the difference from the steering angle data at the previous sampling timing to convert it into angular velocity data and stores it in the data storage 5.

  Steps S <b> 6 and S <b> 7: The turning angle determination unit 10 compares the point data of the GPS sensor 4 with the road map data 8 to determine the timing of the turning point entry and exit points. Then, the data cutout unit 15 cuts out the angular velocity data group belonging to this bend angle period.

  Steps S8 and S9: The FFT calculator 16 multiplies the extracted angular velocity data group by a Hamming window function to reduce the aliasing effect. Then, a discrete Fourier transform FFT is performed. The result is a vector of complex numbers.

  Step S10: The result of the FFT is squared by the squarer 17, and converted to a vector (real vector) representing the energy distribution on the time axis.

  Step S11: The ratio (steering smoothness index) calculation unit 18 integrates the real vector over the entire frequency range to obtain the integral value S1, and also calculates a threshold value Ref1 (here, 0.5 / (This value can be adjusted according to the system.) The integral value S2 is obtained by integration even in the above frequency range, and the ratio R of the high-frequency integral value S2 to the total integral value S1 is obtained. (= S2 / S1) is calculated as a steering smoothness index. Note that Ref1 can be variably set or finely adjustable.

  Step S12: The steering smoothness determination unit 19 compares the steering smoothness index R obtained in step S11 with the driving age determination index Ref2 (here, it can be variably set in the range of 0.10 to 0.25). If it exceeds this Ref2, it is determined that the driver is an elderly driver whose driving ability has been reduced, and the warning output unit 20, for example, “The driving ability has been significantly reduced. Please drive carefully. ”Or“ The driving ability is extremely low. It is recommended that you return your driver's license. ” This warning output is displayed on the screen of the display device 7 and can be printed out and handed to the driver himself.

  Thus, according to the elderly driver support system of the present embodiment, the driving age determination method and the driving age determination program implemented thereby, it is possible to make the elderly driver whose driving ability has decreased notice the decrease in driving ability. it can.

  In addition, the following procedure may be sufficient about the angular velocity calculation of step S5-S7, bending angle determination, and data extraction. First, in step S5, the turning angle determination is performed first. In step S6, a data group belonging to the turning angle travel period is extracted from the steering angle data, and the difference is applied to the steering angle data group cut out in step S7 to turn the turning angle traveling period. An angular velocity data group belonging to the above is obtained, stored in the data storage 5, and the discrete FFT in step S9 is executed on this angular velocity data group. The result is the same.

  (Second Embodiment) An elderly driver support system according to a second embodiment of the present invention, a driving age determination method and a driving age determination program implemented by it will be described.

  The feature of this embodiment is that the turning angle on the road is determined from the acceleration detection data of the in-vehicle acceleration sensor (G sensor) and the steering amount detected by the steering angle sensor, and the hardware configuration is shown in FIG. In addition, the functional configuration of the driving age determination unit 6 is as shown in FIG.

  In the elderly driver support system of the present embodiment, an acceleration sensor 4A is provided instead of the GPS sensor 4 of the first embodiment, and the acceleration sensor 4A attenuates for a period during which the acceleration is detected at a predetermined value or more. A steering amount calculation unit 21 for time-integrating the steering angle data output from the device 13, and the bending angle determination unit 10 determines that the steering amount output from the steering amount calculation unit 21 is a predetermined angle (for example, 90 degrees or more). It is determined that the vehicle is traveling at a corner. In FIGS. 4 and 5, elements common to the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals.

  In the case of the present embodiment, the processing flow of the driving age determination method and the driving method determination program implemented by the elderly driver support system is as shown in FIG. 3 as in the first embodiment. However, only the bending angle determination method in step S6 is different from the first embodiment, and the determination is made based on the acceleration detection period output by the acceleration sensor 4A and the steering amount therebetween.

  Even in the present embodiment, similar to the first embodiment, it is possible to make an elderly driver whose driving ability has decreased notice the decrease in driving ability.

  (Third Embodiment) An elderly driver support system according to a third embodiment of the present invention, a driving age determination method and a driving age determination program which it implements will be described.

  The feature of this embodiment is that the driver's steering smoothness index R is ranked and the driving age for each rank is estimated and presented to the driver. The hardware configuration of the elderly driver support system of the present embodiment is as shown in FIG. 1 as in the first embodiment. The functional configuration of the driving age determination unit 6 is shown in FIG. 6, and includes a driving age ranking unit 22 instead of the warning output unit 20 in the first embodiment shown in FIG. In FIG. 6, elements common to the other embodiments are denoted by the same reference numerals.

  According to the present embodiment, the following processing is performed in step S12 'in the flowchart of FIG. That is, Ref2 of the steering smoothness determination unit 19 is set to a plurality of stages, and it is determined to which rank the steering smoothness index R obtained by the steering smoothness index calculation unit 18 belongs. And if the driving age ranking part 22 exceeds R = 0.1 corresponding to the rank, "The driving age is over 60 years old. The driving ability tends to decrease, so please drive carefully. ”, And if R = 0.15,“ The driving age is over 70 years old. The driving ability is degraded. It is better to stop driving. ”, And further R = 0. If it exceeds 20, a warning corresponding to the rank of driving age is issued, such as "Driving age is over 80. Driving is impossible. It is recommended to return the license."

  In the flowchart of FIG. 7, the same arithmetic processing is performed for the step numbers common to the flowchart shown in FIG. Further, as in the first embodiment, the processes in steps S5 to S7 can be interchanged.

  Thus, according to the present embodiment, since the driving age is presented according to the rank of the steering smoothness index at the turning angle and a warning is also output, the driving ability is provided to the elderly driver whose driving ability is reduced. Can be noticed.

  (Fourth Embodiment) An aged driver support system according to a fourth embodiment of the present invention, a driving age determination method and a driving age determination program implemented by it will be described.

  As in the second embodiment, the feature of this embodiment is that the turning angle on the road is determined from the acceleration detection data of the in-vehicle acceleration sensor (G sensor) and the steering amount detected by the steering angle sensor. In addition, as in the third embodiment, the steering smoothness index R of the driver is ranked, and the driving age for each rank is estimated and presented to the driver. The hardware configuration is the same as that of the second embodiment and is shown in FIG. 5, and the functional configuration of the driving age determination unit 6 is shown in FIG.

  In the elderly driver support system of the present embodiment, instead of the GPS sensor 4 of the first and third embodiments, an acceleration sensor 4A is provided, and the acceleration sensor 4A detects an acceleration of a predetermined value or more. Is provided with a steering amount calculation unit 21 that time-integrates the steering angle data output from the attenuator 13, and the bending angle determination unit 10 determines that the steering amount output from the steering amount calculation unit 21 is a predetermined angle (for example, 90 degrees or more). ), It is determined that the vehicle is traveling at a corner.

  In the case of the present embodiment, as in the third embodiment, the driving age ranking unit 22 sets Ref2 in a plurality of stages in step S12 ′, and if R = 0.1 is exceeded, “driving age 60 Beyond the age. Please drive carefully as the driving ability tends to decline. "And if R = 0.15," The driving age is over 70. The driving ability is low. "It is better to stop driving." And if R exceeds 0.20, "The driving age is over 80. Driving is impossible. It is recommended to return the driver's license." A warning corresponding to each rank is issued along with a gradual ranking of driving age.

  Even in this embodiment, as in the third embodiment, the driving age is presented and the warning is output according to the rank of the steering smoothness index at the turning angle. It is possible to make the elderly driver aware of the decrease in driving ability.

  In the present invention, the determination of the turning angle is arbitrary, and the tester who rides with the driver inputs the turning angle entry and exit buttons together with the time information at the time, and the angular velocity data cutout unit 15 It is also possible to cut out the angular velocity data group belonging to the turning point entry / exit period based on the time information and perform the FFT processing.

The block diagram of the elderly driver support system of the 1st Embodiment of this invention. The functional block diagram of the driving age determination part in the 1st Embodiment of this invention. The flowchart of the driving age determination process by the 1st Embodiment of this invention. The block diagram of the elderly driver support system of the 2nd Embodiment of this invention. The functional block diagram of the driving age determination part in the 2nd Embodiment of this invention. The functional block diagram of the driving age determination part in the 3rd Embodiment of this invention. The flowchart of the driving age determination process by the 3rd Embodiment of this invention. The functional block diagram of the driving age determination part in the 4th Embodiment of this invention. A map of a set test course for demonstrating the utility of the present invention. Graph of energy distribution of steering angular velocity of middle class driver. The graph of the energy distribution of the steering angular velocity of an elderly driver. The graph which shows distribution of the steering smoothness parameter | index of a middle class driver and an elderly driver.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Steering wheel 2 ... Steering shaft 3 ... Steering angle sensor 4 ... GPS sensor 4A ... Acceleration sensor 5 ... Data storage 6 ... Driving age determination part 7 ... Output part 8 ... Road map data 10 ... Turn angle determination part 14 ... Difference machine 16 ... FFT calculator 17 ... Squarer 18 ... Steering smoothness index calculation unit 19 ... Steering smoothness determination unit 20 ... Warning output unit 21 ... Steering amount calculation unit 22 ... Driving age ranking unit

Claims (18)

A corner judging means for judging a corner on the road;
A steering angle sensor that detects a steering angle of the steering wheel and outputs the steering wheel at a first predetermined cycle;
Angular velocity calculation means for obtaining angular velocity data by differentiating the steering angle signal of the steering angle sensor with respect to time;
Fourier transform means for Fourier transforming the angular velocity data group belonging to the period from the entry point to the exit point of the turn angle determined by the turn angle determination means, and calculating the energy distribution on the frequency axis by squaring the conversion value; ,
Of the energy distribution calculated by the Fourier transform means, an integral value (high-range integral value) of a value in a frequency region higher than a predetermined frequency threshold value and an integral of values in the entire frequency region of the angular velocity Fourier transform value Integration means for obtaining a value (global integration value);
Steering smoothness index calculating means for determining, as a steering smoothness index, the ratio of the high-frequency integrated value obtained by the integrating means to the total integrated value;
A driving age determining means for comparing the steering smoothness index obtained by the steering smoothness index calculating means with a safe driving index threshold and outputting a warning when the steering smoothness index exceeds the safe driving index threshold; Elderly driver support system provided. A corner judging means for judging a corner on the road;
A steering angle sensor that detects a steering angle of the steering wheel and outputs the steering wheel at a first predetermined cycle;
Angular velocity calculation means for obtaining angular velocity data by differentiating the steering angle signal of the steering angle sensor with respect to time;
Fourier transform means for Fourier transforming the angular velocity data group belonging to the period from the entry point to the exit point of the turn angle determined by the turn angle determination means, and calculating the energy distribution on the frequency axis by squaring the conversion value; ,
Of the energy distribution calculated by the Fourier transform means, an integral value (high-range integral value) of a value in a frequency region higher than a predetermined frequency threshold value and an integral of values in the entire frequency region of the angular velocity Fourier transform value Integration means for obtaining a value (global integration value);
Steering smoothness index calculating means for obtaining a ratio of the high-frequency integral value obtained by the integrating means and the total integral value as a steering smoothness index;
Correspondence table means of steering smoothness index and driving age index;
An elderly driver support system comprising driving age determining means that converts the steering smoothness index obtained by the steering smoothness index calculating means into a driving age index and outputs the result by referring to the correspondence table means.   3. The elderly person according to claim 1, wherein the turning angle determination unit includes road map data and GPS, and determines the turning angle when a point detected by the GPS corresponds to a turning angle on the road map. Driver support system.   The bending angle determination means includes an acceleration sensor and a steering angle integrator that integrates the steering angle output from the steering angle sensor to obtain a bending angle, and the acceleration sensor detects an acceleration equal to or greater than a predetermined threshold value. 3. The elderly driver support system according to claim 1, wherein when the integral value of the steering angle integrator during a certain period becomes an angle equal to or greater than a predetermined threshold, the turning angle is determined as a turning angle.   The elderly driver support system according to any one of claims 1 to 4, wherein the predetermined threshold value determined by the integrating means as the high-frequency integrated value is 0.5 / sec.   The elderly driver support system according to claim 1, wherein the safe driving index threshold is set to any value within a range of 0.10 to 0.25. A corner determination step for determining a corner on the road;
An angular velocity calculation step for obtaining angular velocity data by differentiating the steering angle signal of the steering angle sensor with respect to time,
A Fourier transform step of Fourier transforming the angular velocity data group belonging to the period from the entry point to the exit point of the curve angle determined in the curve angle determination step, and calculating the energy distribution on the frequency axis by squaring the conversion value; ,
Of the energy distribution calculated in the Fourier transform step, an integral value (high region integral value) of a frequency region value higher than a predetermined frequency threshold value and an integral of all angular region values of the angular velocity Fourier transform value An integration step for obtaining a value (global integration value);
Steering smoothness index calculating step for obtaining a ratio of the high-frequency integrated value obtained in the integrating step to the total integrated value as a steering smoothness index;
A driving age determination step of comparing the steering smoothness index obtained in the steering smoothness index calculation step with a safe driving index threshold and outputting a warning when the steering smoothness index exceeds the safe driving index threshold; Having a driving age determination method. A corner determination step for determining a corner on the road;
An angular velocity calculation step for obtaining angular velocity data by differentiating the steering angle signal of the steering angle sensor with respect to time,
A Fourier transform step of Fourier transforming the angular velocity data group belonging to the period from the entry point to the exit point of the curve angle determined in the curve angle determination step, and calculating the energy distribution on the frequency axis by squaring the conversion value; ,
Of the energy distribution calculated in the Fourier transform step, an integral value (high region integral value) of a frequency region value higher than a predetermined frequency threshold value and an integral of all angular region values of the angular velocity Fourier transform value An integration step for obtaining a value (global integration value);
Steering smoothness index calculating step for obtaining a ratio of the high-frequency integrated value obtained in the integrating step to the total integrated value as a steering smoothness index;
Driving age determination having a driving age determination step that converts a steering smoothness index obtained in the steering smoothness index calculation step into a driving age index and outputs it with reference to a correspondence table between the steering smoothness index and the driving age index Method.   9. The driving age determination method according to claim 7, wherein, in the turning angle determination step, a point detected by GPS is associated with road map data, and a turning angle is determined when it corresponds to a turning angle on a road map. .   In the bending angle determination step, the steering angle output from the steering angle sensor is integrated to obtain a bending angle, and the bending angle during a period in which the acceleration sensor detects an acceleration equal to or higher than a predetermined threshold value is the predetermined threshold value. 9. The driving age determination method according to claim 7 or 8, wherein a turning angle is determined when the above angle is reached.   The driving age determination method according to any one of claims 7 to 10, wherein in the integration step, a predetermined threshold value for determining the high-frequency integration value is set to 0.5 / sec.   The driving age determination method according to claim 7, wherein the safe driving index threshold is set to any value within a range of 0.10 to 0.25. A corner determination step for determining a corner on the road;
An angular velocity calculation step for obtaining angular velocity data by differentiating the steering angle signal of the steering angle sensor with respect to time,
A Fourier transform step of Fourier transforming the angular velocity data group belonging to the period from the entry point to the exit point of the curve angle determined in the curve angle determination step, and calculating the energy distribution on the frequency axis by squaring the conversion value; ,
Of the energy distribution calculated in the Fourier transform step, an integral value (high region integral value) of a frequency region value higher than a predetermined frequency threshold value and an integral of all angular region values of the angular velocity Fourier transform value An integration step for obtaining a value (global integration value);
Steering smoothness index calculating step for obtaining a ratio of the high-frequency integrated value obtained in the integrating step to the total integrated value as a steering smoothness index;
A driving age determination step that compares the steering smoothness index obtained in the steering smoothness index calculation step with a safe driving index threshold and outputs a warning when the steering smoothness index exceeds the safe driving index threshold; A driving age determination program that is executed by a computer. A corner determination step for determining a corner on the road;
An angular velocity calculation step for obtaining angular velocity data by differentiating the steering angle signal of the steering angle sensor with respect to time,
A Fourier transform step of Fourier transforming the angular velocity data group belonging to the period from the entry point to the exit point of the curve angle determined in the curve angle determination step, and calculating the energy distribution on the frequency axis by squaring the conversion value; ,
Of the energy distribution calculated in the Fourier transform step, an integral value (high region integral value) of a frequency region value higher than a predetermined frequency threshold value and an integral of all angular region values of the angular velocity Fourier transform value An integration step for obtaining a value (global integration value);
Steering smoothness index calculating step for obtaining a ratio of the high-frequency integrated value obtained in the integrating step to the total integrated value as a steering smoothness index;
Referring to the correspondence table between the steering smoothness index and the driving age index, the computer executes a driving age determination step for converting the steering smoothness index obtained in the steering smoothness index calculating step into a driving age index and outputting it. A driving age determination program characterized by that.   15. The driving age determination program according to claim 13 or 14, wherein, in the turning angle determination step, a point detected by GPS is associated with road map data and is determined to be a turning angle when it corresponds to a turning angle on a road map. .   In the bending angle determination step, the steering angle output from the steering angle sensor is integrated to obtain a bending angle, and the bending angle during a period in which the acceleration sensor detects an acceleration equal to or higher than a predetermined threshold value is the predetermined threshold value. 15. The driving age determination program according to claim 13 or 14, wherein a turning angle is determined when the above angle is reached.   The driving age determination program according to any one of claims 13 to 16, wherein in the integration step, a predetermined threshold value for determining the high-frequency integration value is set to 0.5 / sec.   The driving age determination program according to claim 13, wherein the safe driving index threshold is set to any value within a range of 0.10 to 0.25.

Images