JP2012219759A - Driving assistance device - Google Patents

Abstract

A vehicle driving support device for improving fuel consumption is provided.
SOLUTION: A means for detecting an accelerator opening of a host vehicle, a means 136 for calculating an autocorrelation function of the accelerator opening based on time series data of the accelerator opening, and a value of the autocorrelation function, Means 137 for calculating the frequency of accelerator operation of the own vehicle, means for detecting the acceleration of the own vehicle, means 131 for calculating a power spectrum corresponding to the frequency from frequency analysis of acceleration, and calculating a single regression line of the power spectrum And a means 133 for calculating the maximum value of the change amount of the slope of the single regression line in a predetermined frequency range as the maximum value of the slope, and an apparatus for assisting the driving of the vehicle to improve fuel consumption. This device provides driving assistance when the frequency of the accelerator operation is lower than a predetermined value and the slope maximum value indicates a traffic jam sign in front of the host vehicle.
[Selection] Figure 2

Description

  The present invention relates to an apparatus for supporting driving of a vehicle so as to improve fuel efficiency, and more specifically, to a driving support apparatus for improving fuel efficiency based on the periodicity of accelerator operation and a traffic jam sign.

  Conventionally, various devices for assisting driving so as to achieve better fuel consumption have been proposed. For example, in Patent Document 1, an autocorrelation function of the accelerator opening is calculated from time-series data of the accelerator opening, and whether the current accelerator operation is an accelerator operation with good fuel consumption according to the calculated autocorrelation function value. A driving support device that performs a display indicating whether or not is described.

JP 2010-241212 A

  However, in the method of Patent Document 1, it is determined whether or not the current accelerator operation is an accelerator operation with good fuel efficiency by focusing only on the accelerator operation. It does not consider the presence or absence. Therefore, this conventional method has room for improvement in driving support for further improving fuel efficiency.

  Accordingly, an object of the present invention is to provide a vehicle driving support device for improving fuel efficiency in consideration of the periodicity of accelerator operation and a traffic jam sign.

  The present invention is an apparatus for assisting driving of a vehicle to improve fuel efficiency. The apparatus includes means for detecting the accelerator opening of the host vehicle, means for calculating an autocorrelation function of the accelerator opening based on time-series data of the detected accelerator opening, and a calculated autocorrelation function Based on the value of the vehicle, means for calculating the accelerator operation frequency of the host vehicle, means for detecting the acceleration of the host vehicle, means for calculating a power spectrum corresponding to the frequency from frequency analysis of the detected acceleration, and the calculated power Means for calculating a single regression line of the spectrum, and calculating a maximum value of the change amount of the slope of the single regression line in a predetermined frequency range as a maximum value of the slope, and the frequency of the accelerator operation is lower than the predetermined value, and Driving assistance is provided when the maximum value of inclination indicates a sign of traffic jam ahead of the host vehicle.

  According to the present invention, when the accelerator operation is at a low frequency, that is, when the vehicle is running at a low frequency and traffic congestion is expected, driving assistance for improving fuel efficiency, in other words, improving energy management efficiency. Can be provided in a timely manner.

  According to one aspect of the invention, driving assistance includes providing timing for using the energy management meter.

  According to one aspect of the present invention, it is possible to appropriately inform the driver of the timing at which fuel efficiency can be improved and energy management efficiency is improved.

  According to one aspect of the invention, driving assistance includes performing cruise control.

  According to one aspect of the present invention, it is possible to appropriately inform the driver of the use timing of cruise control, which can improve fuel efficiency and improve energy management efficiency.

It is a block diagram which shows the structure of the driving assistance device according to one Example of this invention. It is a block diagram which shows the structure of the control part according to one Example of this invention. FIG. 4 shows an acceleration spectrum according to one embodiment of the present invention. It is a figure for demonstrating the relationship between the traffic jam sign degree and inclination maximum value according to one Example of this invention. It is a schematic diagram of the accelerator operation with respect to the accelerator pedal according to one Example of this invention. It is a figure which shows the transition of the driving | running state at the time of accelerator operation with favorable and unfavorable fuel consumption performed according to one Example of this invention, and accelerator opening. It is a figure which shows transition with respect to the lag of the accelerator opening degree at the time of accelerator operation with favorable and unfavorable fuel consumption according to one Example of this invention. It is a figure which shows the example of arrangement | positioning of a display device according to one Example of this invention. It is a figure which shows the example of a display by a display according to one Example of this invention. 4 is a control flowchart for driving assistance according to an embodiment of the present invention. 3 is a flowchart of a traffic jam sign according to one embodiment of the present invention. 4 is a flowchart for calculating an accelerator operation frequency according to an embodiment of the present invention;

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a driving support device 10 according to an embodiment of the present invention. The driving support device 10 is mounted on a vehicle. The driving support device 10 can be mounted on a vehicle as one device or as a part of another device.

  The driving support device 10 includes a driving state detection unit 11, a control unit 13, a storage unit 15, a speaker 17, a travel control unit 18, and a display device 19. In addition, when the vehicle includes a navigation device, the control unit 13 may be incorporated therein. Further, the speaker 17 and the display device 19 may use corresponding functions provided in the navigation device.

  The driving state detection unit 11 detects the driving state of the vehicle. In this embodiment, the vehicle speed (acceleration) and the accelerator opening are detected. These can be detected by any known technique. For example, a vehicle speed sensor and an accelerator opening sensor are provided in the vehicle, and the vehicle speed (acceleration) and the accelerator opening can be obtained from these detected values, respectively.

  The control unit 13 can be realized by an electronic control unit (referred to as ECU) that is a computer including a central processing unit (CPU) and a memory. The control unit 13 stores the vehicle speed (acceleration) and the accelerator opening detected by the driving state detection unit 11 in the storage unit 15 realized by a storage device such as a memory. The control unit 13 outputs a control signal to control driving of various actuators, a constant speed traveling (CC: cruise control) system, and the like. The control unit 13 will be further described later.

  The speaker 17 notifies the driver by outputting a predetermined warning sound or sound according to a control signal from the control unit 13. The display device 19 includes a display such as an LCD, and can be a display having a touch panel function. The display device 19 may be configured to include an audio output unit and an audio input unit. The display device 19 notifies the driver by displaying predetermined warning information or blinking or lighting a predetermined warning light in response to a control signal from the notification control unit 13.

  FIG. 2 is a block diagram showing a configuration of the control unit 13 according to an embodiment of the present invention. The function of each block of the control unit 13 will be described. The frequency analysis unit 131 performs frequency analysis on the acceleration of the host vehicle detected by a vehicle speed sensor (not shown), and calculates a power spectrum. FIG. 3 shows examples of power spectra in two different running states (a) and (b). In FIG. 3, acceleration spectra 51 and 53 corresponding to frequencies are illustrated as power spectra.

  The single regression line calculation unit 132 performs a single regression analysis on the obtained power spectrum and calculates a single regression line. In the example of FIG. 3, the straight lines indicated by reference numerals 52 and 54 are simple regression lines obtained for the acceleration spectra 51 and 53, respectively.

  The slope maximum value calculation unit 133 calculates a slope maximum value from the obtained single regression line. In the example of FIG. 3, first, the slopes of the single regression lines 52 and 54 are calculated. That is, in FIG. 3, the slope α (= Y / X) based on the change X of the spectral value in a predetermined frequency range Y (for example, a frequency range corresponding to a time range of several seconds to several minutes, 0 to 0.5 Hz, etc.). ) Is calculated. In FIG. 3, the inclinations α1 and α2 at (a) and (b) are obtained.

Next, a difference between the obtained inclinations α, that is, a difference Δα (= α _k −α _k−1 ) between the inclinations α _k and α _k−1 at a predetermined time interval is calculated. The maximum value of the time change of the obtained difference Δα or the time change of the parameter (for example, absolute value | Δα |, square value (Δα) ^2, etc.) obtained from the difference Δα is obtained. The obtained local maximum value is stored as a slope local maximum value in a memory (RAM or the like) or the storage unit 15 in the processing device 14.

  The traffic jam sign calculation unit 134 calculates a traffic jam sign degree according to the slope maximum value calculated by the slope maximum value calculation unit 133. Here, the traffic jam sign is defined as a parameter indicating the possibility of traffic jam on the road (lane) in front of the host vehicle. In other words, the traffic jam predictor increases when the possibility of traffic jam is high, and decreases when the possibility is low. In the present invention, this traffic jam sign degree is calculated from the slope maximum value.

  FIG. 4 is a diagram for explaining the relationship between a traffic jam sign and a slope maximum value. The straight lines 56 and 57 in FIG. 4 are single regression lines obtained by the single regression line calculation unit 132 in the same manner as the straight lines 52 and 54 in FIG. The single regression line 56 is an example when the slope α is small, and the single regression line 57 is an example when the slope α is large. An arbitrary value can be set as the threshold value for determining the magnitude of the traffic jam sign degree, but “−45 degrees”, which is generally known as (1 / f) fluctuation characteristics, can be set as the value. .

  When the inclination α is small, it corresponds to a case where the shock wave (vibration, fluctuation) received from the preceding vehicle is small, and corresponds to a case where the distance between the vehicles is difficult to shorten and the vehicle group is difficult to be dense, that is, the possibility of traffic congestion is low. . In this case, the traffic jam sign is a small value. Conversely, when the slope α is large, it corresponds to the case where the shock wave (vibration, fluctuation) received from the preceding vehicle is large, and the distance between the vehicles tends to be short and the vehicle group tends to become dense, that is, there is a high possibility of traffic jams. Equivalent to. In this case, the sign of congestion is a large value. The shock wave (vibration, fluctuation) referred to here means that each vehicle repeats acceleration and deceleration operations to propagate the operation (back and forth movement) as a kind of vibration to the rear vehicle. In the example of FIG. 4, as the inclination α increases from the single regression line 56 toward the single regression line 57, the possibility of traffic jams increases, that is, the traffic jam sign rate increases.

Therefore, in the present invention, the magnitude of the slope of this single regression line, more specifically, the slope maximum value calculated by the slope maximum value calculation unit 133 (for example, | Δα |, (Δα) ^2, etc.) The traffic congestion sign is calculated according to the maximum value. Specifically, for example, a function (for example, y = ax + b) indicating a relationship between the slope maximum value (x) and the traffic jam sign degree (y) is obtained in advance, and the slope maximum value calculated by the slope maximum value calculation unit 133 is obtained. The traffic congestion predicting degree (y) for the value (x) is calculated. Alternatively, the relationship between the maximum value of the slope and the corresponding traffic jam sign value is created in advance and stored in a memory as a table, and the traffic jam sign level for the calculated slope maximum value can be obtained by referring to the table. it can.

  Next, functions of the blocks 135 to 137 in FIG. 2 will be described. First, the basic concept for understanding these functions will be explained.

  FIG. 5 is a schematic diagram of an accelerator operation with respect to the accelerator pedal 300. When driving with good fuel efficiency such as cruise driving (constant speed driving), an on / off (pushing or returning) operation is performed so as to be within the fluctuation range as indicated by an arrow 303. The frequency of fine on / off operations is relatively high. On the other hand, when driving with unfavorable fuel consumption, an on / off operation is performed so that the fluctuation range is large as indicated by an arrow 305, and the frequency of a large and loose on / off operation is relatively high. In other words, when the required time from when the accelerator pedal is pressed until it returns is relatively long, it means a low frequency pedal operation, and when it is relatively short, it means a high frequency pedal operation.

  FIG. 6 shows the time transition of the accelerator opening. FIG. 6 (a) shows a time transition of the accelerator opening when the accelerator operation is performed within the fluctuation range as indicated by the arrow 303 in FIG. ing. FIG. 5B shows the time of accelerator opening when the accelerator operation is performed in the fluctuation range as indicated by the arrow 305 in FIG. 5 and the fuel consumption is not satisfactory as compared with FIG. Transition is shown. The scales of the time axes of (a) and (b) are different, and the times t1, t2, and t3 of (a) correspond to the times t1, t2, and t3 of (b), respectively.

  6 (c) and 6 (d) show an attractor of the dynamic system, and time series data of the accelerator opening as shown in (a) and (b), respectively, is obtained with time delay coordinates. It is embedded in the three-dimensional state space by the system. Specifically, if the time series data of the accelerator opening is A (t) (t = 1, 2, 3,...), The vector V (t) = (A (t), A (t + τ), Considering A (t + 2τ)), the trajectories when the vectors V (t) are sequentially plotted in the three-dimensional state space are shown in these drawings. Here, τ represents a time delay.

  As is clear by comparing (a) and (b), and as is clear by comparing (c) and (d), fuel efficiency is poor compared to high-frequency accelerator operation with good fuel efficiency. It can be seen that the low-frequency accelerator operation has a greater increase / decrease in the accelerator pedal opening, and the on / off operation is performed more slowly. That is, it can be seen that the accelerator operation with poor fuel efficiency moves at a lower frequency than the accelerator operation with good fuel efficiency. Therefore, it is necessary to improve the fuel consumption by prompting the driver to operate the accelerator at a higher frequency.

  In this embodiment, whether or not the accelerator operation is moving at a high frequency or a low frequency is determined using an autocorrelation function. It can be considered that the probability distribution of the accelerator operation is almost equal in a short time. Therefore, when the sample values of the accelerator opening are acquired in time series, this time series can be considered as a time series of weak steadiness.

Here, as described above, when the time series data of the accelerator opening is A (t) (t = 1, 2, 3,...), The following equation is established. Expression (1) is an expression for calculating n averages of the sample values A (t) of the accelerator opening, and Expression (2) is an expression for calculating the autocovariance function R using the average value. Yes, Equation (3) is an equation for calculating the autocorrelation function ρ using the autocovariance function R. k indicates a lag.

  The autocorrelation function ρ is normalized between zero and 1 and is a function of lag k. The value of the autocorrelation function ρ is calculated to have a value closer to 1 as the signal has a higher periodicity (high frequency).

  Referring now to FIG. 7, (a) shows the transition of the autocorrelation function value calculated with respect to lag k in the case of driving with good fuel efficiency as shown in (a) of FIG. (B) shows the transition of the autocorrelation function value calculated with respect to the lag k in the case of driving with poor fuel consumption as shown in (b) of FIG. The autocorrelation function value takes a peak value of 1 when the lag k is zero, and then decays with time. When the autocorrelation function value of the lag k from zero to a predetermined time T is compared, from (b) In (a), the variation of the autocorrelation function value is smaller.

  That is, in the case of the operation as shown in (a), the accelerator pedal is turned on and off with a high frequency operation as shown in (a) of FIG. Time series data is obtained. Therefore, the autocorrelation function value becomes a behavior that rapidly decreases with respect to the lag, and the time required for attenuation is shorter than that in (b). On the other hand, in the case of operation as shown in (b), since the accelerator pedal is turned on and off with low-frequency operation as shown in FIG. 6 (b), a signal with low periodicity (low frequency) is used. As a result, time series data of the accelerator opening is obtained. Therefore, the autocorrelation function value becomes a behavior that gradually decreases with the lag, and the time required for attenuation is longer than that in (a).

  In this way, by examining the decay behavior of the autocorrelation function value, it is determined whether or not the accelerator operation with good fuel efficiency is being performed, that is, whether the operation is high frequency (good fuel consumption) or low frequency operation (good fuel consumption). Can be judged. This is because the fuel efficiency can be estimated from the presence or absence of the periodicity of the pedal operation.

  Returning to FIG. 2, in block 135, the accelerator opening is acquired as time-series data. Specifically, time-series data as illustrated in FIG. 6 is obtained from a plurality (N) of accelerator openings stored in the storage unit 15. In block 136, an autocorrelation function ρ is calculated from the acquired time series data of the accelerator opening. Specifically, the value of the autocorrelation function ρ (autocorrelation function value) is calculated using the above-described equations (1) to (3).

  In block 137, the frequency of the accelerator operation is calculated. Specifically, the calculated autocorrelation function value has a high frequency when the attenuation rate ρr (= Δρ / ΔT) at a predetermined time interval is larger than the predetermined value, and is lower when it is smaller than the predetermined value. And As described with reference to FIG. 7, the frequency of attenuation of the autocorrelation function value within a predetermined time increases as the accelerator operation becomes higher in frequency, so whether or not the attenuation rate ρr is greater than the predetermined value. This is because it is possible to determine whether the frequency is high or low. By calculating the frequency level, it is possible to determine whether or not the fuel efficiency is good.

  The driving support determination unit in block 138 determines whether or not to perform driving support from the traffic jam sign degree calculated in block 134 and the accelerator operation frequency calculated in block 137. Specifically, for example, when the traffic sign is larger than a predetermined value and the accelerator operation frequency is low, it is determined to perform driving support. If it is assumed that the fuel economy tends to deteriorate and this tendency is expected to increase due to the presence of traffic signs, this will reduce the tendency of the fuel economy to worsen, and thus provide driving assistance aimed at improving the fuel efficiency. It becomes possible to provide the timing to provide. On the other hand, if the traffic congestion sign is smaller than the predetermined value and the accelerator operation frequency is high, the fuel consumption is not in a tendency to deteriorate, and the tendency to further deteriorate is low. Make a decision not to make it.

  The driving support determination unit 138 sends a control signal including the determination result to the travel control unit 139, the notification control unit 140, and the communication control unit 141. When the traveling control unit 139 receives a determination result for performing driving assistance, the traveling control unit 139 transmits, for example, a control signal for executing cruise control to the corresponding system. As a result, it is possible to follow the vehicle ahead without operating the accelerator, and as a result, it is possible to improve and improve fuel consumption. Note that execution of cruise control is one example of traveling control, and traveling control may be performed by controlling various actuators that are useful for improving fuel consumption. These various actuators are used as a general term for a plurality of actuators, and include, for example, a throttle actuator, a brake actuator, a steering actuator, and the like. In addition, although the driving support information may be provided by a display device, there may be a difference in recognition time by the driver and a difference in driving behavior characteristics. Therefore, traveling control such as cruise control applies the present invention. It is more suitable as a system to perform.

  The notification control unit 140 performs notification control of the display device 19 and the speaker 17 when receiving a determination result for driving assistance. For example, in order to urge the use of the energy management meter, the notification control unit 140 turns on a display that prompts the user to urge the use of the energy management meter, or sends a control signal for transmitting from the speaker 17 by voice.

  FIG. 8 is a diagram illustrating an arrangement example of the display device in the vehicle compartment according to an embodiment of the present invention. In FIG. 8, the case where the display part 63 is installed in the lower part of the room mirror 62 located on the centerline C of a vehicle interior, and the case where it installs on the front cover part 60 are illustrated. The display unit 63 may be incorporated as a part of the display unit 61 of the navigation device or may be disposed on the upper part thereof. The display unit 63 is preferably located near the center of the passenger compartment. The reason is that the display unit 63 is positioned near the center of the passenger compartment, so that the display unit 63 can be placed in the driver's field of view regardless of whether the driver's line of sight is directed to the left or right. .

  FIG. 9 is a diagram illustrating a display example of the display unit 63. The display unit 63 includes a lighting unit 631 that displays use of the energy management meter, and a lighting unit 632 that displays use of cruise control. The lighting unit 631 lights up or blinks in a predetermined color (for example, yellow) in order to encourage the use of the energy management meter. When the cruise control is used, the lighting unit 632 lights or blinks in a predetermined color (for example, green). In addition, the character display in the lighting parts 631 and 632 in the figure is described for explanation, and may or may not be actually displayed. These displays allow the driver to quickly and visually grasp whether or not the energy management meter and cruise control are being used.

  The display block 633 lights or blinks in a predetermined color (for example, red) when the traffic congestion sign degree calculated by the traffic congestion sign calculation unit 134 is larger than a predetermined value. In the display block 634, the state of fuel consumption, for example, “fuel deterioration”, “good fuel consumption”, “current fuel consumption (km / l)”, and the like are displayed. Note that the display blocks 633 and 634 can be arbitrarily set as necessary, and are not necessarily required.

  Display blocks 635, 636, and 637 are switch buttons, a switch for turning off the display of the lighting units 631 and 632, a switch for turning off the display of the display block 633, and a switch for turning off the display of the entire display unit 63, respectively. . The driver can manually stop the corresponding display function by pressing (touching) each switch.

  The communication device 21 communicates with another vehicle or a server device (not shown) or a relay station (not shown) by wireless communication under the control of the communication control unit 141, and calculates a traffic jam sign output from the traffic jam sign calculation unit 134. A result and position information are transmitted in association with each other, and traffic jam information or the like is received from another vehicle or the like. The acquired information is sent to the notification control unit 140 or the travel control unit 139 via the communication control unit 141.

  FIG. 10 is a flowchart of control for driving assistance according to an embodiment of the present invention. This flow is executed at a predetermined cycle in the control unit 13 (FIG. 1). The details of each step are as already described in the description of each block in FIG. In step S2, it is determined whether or not the accelerator operation has a low frequency. If this determination is Yes, in the next step S4, it is determined whether or not there is a traffic jam sign. When this determination is Yes, in the next step S6, a determination is made that traffic congestion and deterioration of fuel consumption are expected on the destination road. In the next step S8, driving assistance, that is, various controls and presentations are performed in order to prevent deterioration of the fuel consumption.

  FIG. 11 is a flowchart of a traffic jam sign according to one embodiment of the present invention. This flow is executed at a predetermined cycle in the control unit 13 (FIG. 1). The details of each step have already been described in the description of blocks 131 to 134 in FIG. In step S12, the vehicle speed sensor 11 detects the acceleration of the host vehicle. In step S14, acceleration spectrum single regression maximization is performed. More specifically, the above-described inclination maximum value is calculated (blocks 131 to 133 in FIG. 2). In step S16, the traffic sign is calculated (block 134 in FIG. 2). In step S18, it is determined whether there is a traffic jam sign, that is, whether the traffic jam sign degree is greater than a predetermined value. If this determination is Yes, the presence or absence of a traffic jam sign is output in the next step S20. If the determination in step S18 is No, the process returns to step S14 and the subsequent flow is repeated.

  FIG. 12 is a flowchart for calculating the frequency of an accelerator operation according to an embodiment of the present invention. This flow is executed at a predetermined cycle in the control unit 13 (FIG. 1). The details of each step have already been described in the description of blocks 135 to 137 in FIG. In step S22, the accelerator opening is detected by an accelerator opening sensor (not shown). In step S24, the accelerator opening is acquired as time series data (block 135 in FIG. 2). In step S26, the autocorrelation function ρ is calculated from the acquired time series data of the accelerator opening (block 136 in FIG. 2). In step S28, an attenuation rate ρr (= Δρ / ΔT) at a predetermined time interval of the autocorrelation function value is calculated. In step S30, it is determined whether or not the attenuation rate ρr is smaller than a predetermined value. If this determination is Yes, it is determined in the next step S32 that the frequency of the accelerator operation is low, and the determination result is output (block 137 in FIG. 2). If the determination in step S30 is No, the process returns to step S24 and the subsequent flow is repeated.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and can be modified and used without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Driving assistance apparatus 13 Control part 51, 53 Acceleration (power) spectrum 52, 54, 56, 57 Single regression line 63 Display part 300 Accelerator pedal

Claims (3)

A device for supporting driving of a vehicle to improve fuel consumption,
Means for detecting the accelerator opening of the host vehicle;
Means for calculating an autocorrelation function of the accelerator opening based on the time-series data of the detected accelerator opening;
Means for calculating the accelerator operation frequency of the vehicle based on the calculated autocorrelation function value;
Means for detecting the acceleration of the host vehicle;
Means for calculating a power spectrum corresponding to the frequency from frequency analysis of the detected acceleration;
Means for calculating a single regression line of the calculated power spectrum, and calculating a maximum value of a change amount of the slope of the single regression line in a predetermined frequency range as a slope maximum value,
A driving support device that performs driving support when the frequency of the accelerator operation is lower than a predetermined value and the maximum value of the slope indicates a traffic jam sign in front of the host vehicle.   The driving support apparatus according to claim 1, wherein the driving support includes giving a timing to use an energy management meter.   The driving assistance apparatus according to claim 1, wherein the driving assistance includes executing cruise control.

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