JP5688809B2 - Driver state estimation device - Google Patents

Description

  The present invention relates to a driver state estimation device for estimating the state of a driver driving a vehicle such as an automobile.

  2. Description of the Related Art Conventionally, a wakefulness estimation device has been developed for estimating the wakefulness of a driver who is driving a vehicle for the purpose of appropriately operating a vehicle such as an automobile.

  The present applicant has proposed a technique for estimating the driver's arousal level using the concept of a driver model that models driver recognition, judgment, and operation (see Patent Document 1).

  In the arousal level estimation technique according to Patent Document 1, first, the driver model creation unit uses the difference between the target azimuth angle and the actual azimuth angle (azimuth angle deviation) as a virtual driver input, and uses the actual steering angle as a virtual. As a typical driver output, a driver model representing a virtual driver input / output relationship is created. The driver model operation amount acquisition unit acquires the driver model steering angle by inputting the current azimuth deviation with respect to the driver model. The arousal level estimation unit estimates the driver's arousal level based on the difference between the actual steering angle and the driver model steering angle.

  The difference between the actual steering angle and the driver model steering angle is effective for evaluating whether the operation based on the judgment of the driver (actual steering angle) is based on the linear model (driver model steering angle). It becomes an indicator. Further, it is known that when the operation based on the judgment of the driver (actual steering angle) deviates from the driver model steering angle, the driver's arousal level is highly likely to decrease. Therefore, according to the arousal level estimation technique according to Patent Document 1, it is possible to estimate the driver's arousal level based on the difference between the actual steering angle and the driver model steering angle.

WO2011 / 040390 Publication

  However, in the arousal level estimation technique according to Patent Document 1, a driver model is sequentially generated for each predetermined period, and a residual that is basic data for arousal level estimation is calculated using the generated driver model, and obtained. A series-linked information processing process is adopted in which the driver's arousal level is estimated based on the obtained residual. For this reason, there is a problem that the load related to information processing is excessive, and the speed of the estimation process as a whole cannot be increased due to a request to perform the downstream process after waiting for the upstream process.

  The present invention has been made in view of the above circumstances, and provides a driver state estimation device that can reduce the load related to information processing related to the sequential creation of a driver model and can realize a high speed as an entire estimation process. For the purpose.

In order to achieve the above object, an invention according to claim 1 is a driver state estimating device for estimating a state of a driver who drives a vehicle, and an operation target for acquiring an operation target value of the driver. A value acquisition unit, an actual operation amount acquisition unit that acquires an actual operation amount of the vehicle, an actual operation amount acquisition unit that acquires an actual operation amount of the driver, and a difference between the operation target value and the actual operation amount. A driver model creation unit that creates a driver model that defines the input / output relationship of the driver as an input of the driver, the actual operation amount as the output of the driver, and the driver model creation unit in the past Among the created driver models, a reference model setting unit that sets a reference model suitable for repetitive use as a reference model, and the operation target value by repeatedly using the set reference model. and the difference of the actual operation amount A reference model manipulated variable acquisition unit that obtains a reference model manipulated variable by inputting to the reference model, and estimates a driver's state based on a reference model error obtained from a difference between the actual manipulated variable and the reference model manipulated variable A driver state estimation unit is provided as a main feature.

The invention according to claim 2 is the driver state estimation device according to claim 1 , wherein the reference model setting unit uses standard data belonging to a range widely used as the input and output of the driver. The driver model created by the driver model creation unit is set as the reference model.

The invention according to claim 3 is the driver state estimation device according to claim 2 , wherein the input of the driver is a difference of a target azimuth with respect to an actual azimuth, and the output of the driver is And the standard data is the driving when the amount of change in the actual steering angle per unit time is less than or equal to a predetermined value and the state continues for a predetermined time. It is the data which concerns on a person's input and output.

Moreover, the invention which concerns on Claim 4 is a driver | operator state estimation apparatus as described in any one of Claims 1-3 , Comprising : The said target azimuth angle acquisition part is the said operation target value acquisition part, An azimuth angle The operation target value of the driver is acquired based on the traveling direction information of the vehicle obtained by the acquisition device.

Further, the invention according to claim 5 is the driver state estimation device according to claim 2 , wherein the input of the driver is a difference of a target vehicle position with respect to an actual vehicle position, and the output of the driver is And the standard data is the driving when the amount of change in the actual steering angle per unit time is less than or equal to a predetermined value and the state continues for a predetermined time. It is the data which concerns on a person's input and output.

Moreover, the invention which concerns on Claim 6 is a driver | operator state estimation apparatus of Claim 5 , Comprising: The said operation target value acquisition part is based on the travel lane position information of the said vehicle obtained via an imaging part. The operation target value of the driver is acquired.

  According to the driver state estimation apparatus according to the first aspect, it is possible to reduce the load related to information processing related to the sequential creation of the driver model and to increase the speed of the estimation process as a whole. In addition, the reference model can be easily set. Furthermore, if the driver model estimation device is used when the driver model and the driver are the same, it can be expected to improve the accuracy of the driver status estimation.

  In addition, according to the driver state estimation device according to claim 2, in addition to the effect of reducing the load related to information processing and increasing the speed of the entire driver state estimation process, the driving subject to driver state estimation Attributes of the driver (whether the driver is the same driver as the party of the driver model, whether it is a beginner or an expert if the driver is different from the driver model party), or variable factors such as the driving road environment Regardless, the driver state estimation process can be performed with versatility.

  Further, according to the driver state estimating device according to claim 3, since the specific requirements of the standard data are defined, the effect of reducing the load related to information processing and speeding up the entire driver state estimating process is achieved. In addition, the reference model can be set accurately.

In addition, according to the driver state estimation device according to claim 4 , since the acquisition route related to the operation target value of the driver is clearly defined, the load reduction related to the information processing and the high speed as the entire estimation process of the driver state In addition to the effects related to the optimization, the acquisition related to the operation target value of the driver can be accurately performed.

Further, according to the driver state estimating device according to claim 5 , since the specific requirements of the standard data are defined, as in claim 3 , as the entire load reduction and driver state estimating process related to information processing In addition to the effects related to speeding up, it is possible to accurately set the reference model.

Further, according to the driver state estimating device according to claim 6 , since the acquisition route related to the operation target value of the driver is clearly defined, similarly to claim 4 , the load reduction and driver state related to information processing are reduced. In addition to the effect of speeding up the entire estimation process, acquisition related to the operation target value of the driver can be accurately performed.

It is a conceptual diagram with which it uses for description of the principle which concerns on the arousal level estimation technique used as the premise of this invention. It is a conceptual diagram with which it uses for description of the principle which concerns on the arousal level estimation technique used as the premise of this invention. It is a figure with which it uses for operation | movement description of the arousal level estimation technique used as the premise of this invention. It is a block diagram showing the schematic structure of the arousal level estimation apparatus (driver state estimation apparatus) which concerns on embodiment of this invention. It is a figure where it uses for operation | movement description of the arousal level estimation apparatus (driver state estimation apparatus) which concerns on embodiment of this invention. It is a flowchart figure showing the flow of a normative model setting process among operation | movement of the arousal level estimation apparatus (driver state estimation apparatus) which concerns on embodiment of this invention. It is a flowchart figure showing the flow of a wakefulness estimation process among operation | movement of the wakefulness estimation apparatus (driver state estimation apparatus) which concerns on embodiment of this invention. It is explanatory drawing which matches and represents the relationship of the arousal level with respect to a normative model error.

Hereinafter, a driver state estimating device according to the present invention will be described in detail with reference to the drawings.
It should be noted that the driver state serving as the estimation control in the driver state estimating device according to the present invention is the level related to the arousal level indicating the level related to the driver's arousal and the level of attention / concentration exerted by the driver. This is a concept that comprehensively includes the state relating to the driver. As will be described later, the arousal level in the driver state can be estimated based on the behavior of the vehicle at the time when the driver is asleep or drunken driving, for example.
Therefore, an embodiment of the driver state estimation device according to the present invention will be described by exemplifying a wakefulness estimation device that estimates the driver's wakefulness using the concept of a normative model to be described later.

[Description of Principles Related to Awakening Level Estimation Technology as a Premise of the Present Invention]
First, the principle relating to the arousal level estimation technique which is the premise of the present invention will be described with reference to FIG. 1 and FIG. FIG. 1 and FIG. 2 are conceptual diagrams for explaining the principle of the arousal level estimation technique which is a premise of the present invention. FIG. 3 is a diagram for explaining the operation of the arousal level estimation technique which is a premise of the present invention.
Note that the arousal level is one mode of the driver state as described above. For this reason, the “wakefulness estimation technique” described below can be directly applied to a driver state estimation application by replacing it with “driver state estimation technique”.

  In the example of FIG. 1, for example, it is assumed that the driver controls the azimuth of the vehicle by operating the steering wheel so that the vehicle travels along a white line drawn in the center of the road.

  First, as shown in FIGS. 1 and 2, the driver visually recognizes the azimuth deviation, which is the deviation between the target azimuth for moving the vehicle along the white line and the actual azimuth of the vehicle. Recognize through. In order to eliminate this azimuth deviation, the driver empirically determines how much and in what direction the steering wheel should be operated, and operates the steering wheel according to the determination. Then, an actual steering angle is generated in the steering wheel, and a change in azimuth occurs when the vehicle responds to the same operation. The behavior of the vehicle at this time is influenced by environmental factors (disturbances) such as the friction coefficient and inclination of the traveling road surface, the traveling speed of the vehicle, and the load capacity. A certain actual azimuth angle is generated in the vehicle.

  At this time, the actual azimuth is often different from the previous actual azimuth. Similarly, the target azimuth is often different from the immediately preceding target azimuth. Therefore, as described above, the driver recognizes and judges the azimuth deviation, which is a deviation between the target azimuth and the actual azimuth of the vehicle, from the beginning, and operates the steering wheel according to the judgment. Thereafter, the same steps as described above are repeated.

  For example, when a driver performs a drowsy driving or a drunk driving, an error occurs in the driver's recognition / judgment / operation, and it becomes difficult to drive the vehicle accurately along the white line of the road. As a result, the azimuth deviation tends to increase. Therefore, the driver's arousal level (driver state, the same applies hereinafter) can be estimated by observing the temporal transition of the azimuth deviation (control result).

  However, in the arousal level estimation method described above, the driver's arousal level is estimated without considering the environmental element (disturbance). Therefore, the estimation result inevitably includes errors due to the environmental element (disturbance). Will be included.

  Therefore, the present inventors estimate the driver's arousal level using the concept of a driver model (see FIG. 1) in which the driver's recognition / judgment / operation is modeled in consideration of environmental factors (disturbances). I devised the technology to do.

  In the arousal level estimation technique according to the present invention (awakening level estimation technique as a premise of the present invention), first, the difference between the target azimuth angle and the actual azimuth angle (azimuth angle deviation) is input to the virtual driver, A driver model is defined in which the input / output relationship of the virtual driver is defined using the steering angle as the output of the virtual driver. Since the driver model has a one-to-one input / output relationship, it can be handled as a function. When the current azimuth deviation is input to the driver model thus created, the driver model steering angle is obtained as the output of the driver model.

By the way, as described above, the difference (residual) between the actual steering angle and the driver model steering angle is based on the linear model (driver model steering angle). It becomes an effective index for evaluating whether or not. Further, it is known that when the operation based on the judgment of the driver (actual steering angle) deviates from the driver model steering angle, the driver's arousal level is highly likely to decrease.
Therefore, according to the arousal level estimation technique which is the premise of the present invention, the driver's arousal level can be estimated based on the difference (residual) between the actual steering angle and the driver model steering angle.

However, in the arousal level estimation technique that is the premise of the present invention, a driver model is sequentially created for each predetermined period, and a residual that is basic data for arousal level estimation is calculated using the created driver model, A series-linked information processing process is used in which the driver's arousal level is estimated based on the obtained residual. Specifically, as shown in FIG. 3, the driver model steering angle acquired using the driver model is used in addition to the actual steering angle for calculating the residual. That is, the residual calculation needs to be performed after the driver model creation process is completed. In other words, the driver model creation process has become a bottleneck in the arousal level estimation process.
For this reason, in the arousal level estimation technology that is the premise of the present invention, the load related to information processing is excessive, and the speed of the estimation process as a whole can be increased from the request to perform the downstream process after waiting for the upstream process. There was no problem.

[Outline of Awakening Level Estimation Device According to an Embodiment of the Present Invention]
According to the studies by the present inventors, the function required for the driver model is a function of outputting the driver model steering angle (corresponding to the “driver model operation amount” of the present invention) when the azimuth deviation is input. Even when a certain driver model is used repeatedly, it has been found that if the driver model is set appropriately, the estimation accuracy related to the arousal level is not significantly impaired.
Therefore, in the arousal level estimation device according to the embodiment of the present invention, a driver model that serves as a norm suitable for repeated use is set as a norm model, and this norm model is repeatedly used to sequentially generate driver models. In addition to reducing the load related to information processing, the overall estimation processing speed was increased.

[Block Configuration of Awakening Level Estimation Apparatus 11 According to Embodiment of the Present Invention]
Next, the block configuration of the arousal level estimation apparatus 11 according to the embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 is a block diagram showing a schematic configuration of the arousal level estimation apparatus 11 according to the embodiment of the present invention. FIG. 5 is a diagram for explaining the operation of the awakening level estimation device 11.

As shown in FIG. 4, the arousal level estimation apparatus 11 according to the embodiment of the present invention includes an imaging unit 13, a yaw rate sensor 15, a steering angle sensor 17, a speaker 19, and an ECU (electronic control unit) 20. Configured. These members constituting the awakening level estimation device 11 are mounted on the vehicle Ca.
The arousal level estimation device 11 according to the embodiment of the present invention corresponds to the “driver state estimation device” of the present invention.

  The imaging unit 13 has a function of imaging a road surface including a white line ahead of the traveling direction of the vehicle Ca. The imaging unit 13 is, for example, a CCD (individual imaging device) sensor. The road surface image information including the white line imaged by the imaging unit 13 is sent to a target azimuth angle obtaining unit 21 described later.

The yaw rate sensor 15 has a function of detecting the yaw rate generated in the vehicle Ca (rotational angular velocity around the vertical axis of the center of gravity of the vehicle). The yaw rate detected by the yaw rate sensor 15 is sent to an actual azimuth angle acquisition unit 23 described later.
The yaw rate sensor 15 corresponds to the “azimuth angle acquisition device” of the present invention.

  The steering angle sensor 17 has a function of detecting the actual steering angle (corresponding to the “actual operation amount” of the present invention) of the steering wheel 18 operated by the driver. The steering angle sensor 17 corresponds to the “actual operation amount acquisition unit” of the present invention. The actual steering angle detected by the steering angle sensor 17 is sent to a driver model creation unit 27 and a reference model error calculation unit 39 which will be described later.

  The speaker 19 generates an alarm sound according to the control operation of the alarm control unit 43 described later when the estimation result that the driver's arousal level is below a predetermined level is obtained in the awakening level estimation unit 41 described later. It has a function. This is because stimulating the auditory sense is effective in awakening a driver who is in a low arousal state.

  The ECU 20 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output circuit (including an A / D converter and a D / A converter), and the like. Is done. The CPU executes various processes including a normative model setting process and an arousal level estimation process using the RAM as a work area according to a program stored in the ROM. The flow of these processes will be described later.

  The ECU 20 includes, as logical constituent members, a target azimuth angle acquisition unit 21, an actual azimuth angle acquisition unit 23, an azimuth angle deviation calculation unit 25, a driver model creation unit 27, a bandpass filter 29, and a driver model steering angle acquisition unit. 31, a residual calculation unit 33, a reference model setting unit 35, a reference model steering angle acquisition unit 37, a reference model error calculation unit 39, a wakefulness estimation unit 41, and an alarm control unit 43.

  The target azimuth angle acquisition unit 21 corresponding to the “operation target value acquisition unit” of the present invention has a function of acquiring the driver's target azimuth angle (corresponding to the “operation target value” of the present invention). Specifically, the target azimuth angle obtaining unit 21 recognizes the direction of the white line by performing image processing on the road surface image information including the white line sent from the imaging unit 13. Next, the target azimuth angle acquisition unit 21 calculates and acquires the target azimuth angle based on the amount of deviation in the yaw direction between the direction of the white line and the direction of the vehicle body longitudinal axis.

  The target azimuth angle increases as the amount of deviation in the yaw direction between the white line direction and the vehicle body longitudinal axis direction increases. The sign of the target azimuth is set so that, for example, the clockwise direction is "positive" while the counterclockwise direction is "negative", depending on the direction of the yaw direction deviation of the vehicle longitudinal axis with respect to the white line direction. Is done.

  The actual azimuth angle acquisition unit 23 corresponding to the “actual movement amount acquisition unit” of the present invention has a function of acquiring an actual azimuth angle (corresponding to the “real movement amount” of the present invention). Specifically, the actual azimuth angle acquisition unit 23 acquires the actual azimuth angle by, for example, integrating time series data of the yaw rate detected and output by the yaw rate sensor 15 over a predetermined time.

  The azimuth deviation calculation unit 25 has a function of calculating an azimuth deviation that is a difference between the target azimuth angle acquired by the target azimuth angle acquisition unit 21 and the actual azimuth angle acquired by the actual azimuth angle acquisition unit 23. The azimuth deviation calculated by the azimuth deviation calculation unit 25 is sent to the driver model creation unit 27 and the bandpass filter 29, respectively.

  As shown in FIG. 4, the driver model creation unit 27 creates a driver model that defines the input / output relationship of the driver with the azimuth angle deviation as the driver input and the actual steering angle as the driver output. It has the function to do. A driver model created in the past using the driver model creating unit 27 is stored in a storage unit such as a RAM in a readable state as necessary.

  In the present embodiment, the driver model creation unit 27 is basically configured to function only when performing the normative model setting process. In short, when the driver model creation unit 27 according to the present embodiment performs the reference model setting process for the driver model that has been sequentially created for each predetermined period in the arousal level estimation technique that is the premise of the present invention. A configuration that is created only for this is adopted. This reduces the load of information processing related to the sequential creation of the driver model and speeds up the overall estimation process.

  Incidentally, in the present embodiment, the driver model that defines the input / output relationship between the azimuth angle deviation that is the driver's input and the actual steering angle that is the driver's output is, for example, a first-order differential shown in Equation (1). Given by the equation.

[Driver model] = K / (1 + Ts) Formula (1)
However, K is a gain coefficient and Ts is a time response.

According to the definition of the driver model, the relationship of the following formula (2) is established. The solution of the first-order differential equation [K / (1 + Ts)] that is the driver model is given by the following equation (3).
[Actual steering angle] = [K / (1 + Ts)] × [azimuth angle deviation] Equation (2)
[K / (1 + Ts)] = [actual steering angle] / [azimuth angle deviation] Equation (3)

  Here, the [actual steering angle] on the right side of the equation (3) is detected and output by the steering angle sensor 17. Further, the [azimuth angle deviation] on the right side of the equation (3) is calculated by the azimuth angle deviation calculating unit 25. As described above, both values on the right side of the equation (3) can be acquired. Therefore, the driver model creation unit 27 can create a driver model by calculation by applying Equation (3).

  The band pass filter 29 selects data belonging to a frequency band of 1 to 10 rad / sec with respect to time-series data (including frequency components over a wide band) including the azimuth deviation calculated by the azimuth deviation calculator 25. It has a function to pass through automatically. Here, according to the study by the present inventors, the time series data including the azimuth deviation belonging to the frequency band of 1 to 10 rad / sec is a tendency when the driver's arousal level is lowered (for example, sleepiness is increased). Is known to represent prominently. The time-series data related to the azimuth angle deviation that has passed through the bandpass filter 29 is sent to the driver model steering angle acquisition unit 31 and the reference model steering angle acquisition unit 37, respectively.

  The driver model steering angle acquisition unit 31 corresponding to the “driver model operation amount acquisition unit” of the present invention has a function of acquiring the driver model steering angle. Specifically, the driver model steering angle acquisition unit 31 applies the above-described equation (2), and performs bandpass for the driver model [K / (1 + Ts)] created by the driver model creation unit 27. The driver model steering angle is obtained by multiplying the time-series data related to the azimuth angle deviation that has passed through the filter 29. The driver model steering angle acquired by the driver model steering angle acquisition unit 31 is sent to the residual calculation unit 33.

As shown in FIG. 3, the residual calculation unit 33 is based on the actual steering angle data sent from the steering angle sensor 17 and the driver model steering angle data acquired by the driver model steering angle acquisition unit 31. , “Residual”. Specifically, the residual calculation unit 33 obtains a difference between the actual steering angle data and the driver model steering angle data, and performs a mean square process on the obtained difference data (the obtained difference data is time-series). In the case of data, the mean square process may be performed using the time series data, and the mean square process may be performed using the obtained difference data and the accumulated past difference data. ) To calculate a “residual” as an index representing the driver's arousal level. The “residual” calculated by the residual calculation unit 33 is sent to the arousal level estimation unit 41.
In addition, the input / output which concerns on the ideal model shown in FIG. 3 means the actual input / output which a driver | operator performs. The opposite of the driver model is the actual driver as a party.

  The normative model setting unit 35 has a function of setting, as a normative model, a driver model serving as a norm suitable for repeated use from among the driver models created in the past by the driver model creating unit 27. Specifically, the normative model setting unit 35 sets the driver model created by the driver model creating unit 27 as a normative model using standard data belonging to a range that is widely used as the driver's input and output. To do. Regardless of the driver ’s attributes (whether they ’re the same driver or a different driver, beginner or expert), or any variable factors such as the road environment they ’re driving, This is because the arousal level estimation process can be performed with versatility. The reference model set by the reference model setting unit 35 is sent to the reference model steering angle acquisition unit 37.

  The reference model set by the reference model setting unit 35 may be a driver model other than the driver model previously created by the driver model creation unit 27. In addition, “setting as a reference model” means that the driver model to be set is stored in a storage unit such as a RAM so that it can be read out as necessary in preparation for repeated use. To do.

  The reference model steering angle acquisition unit 37 corresponding to the “reference model operation amount acquisition unit” of the present invention has a function of acquiring a reference model steering angle (corresponding to the “reference model operation amount” of the present invention). Specifically, the normative model steering angle acquisition unit 37 applies the above-described formula (2) and applies a band to the driver model [K / (1 + Ts)] set as the normative model by the normative model setting unit 35. The reference model steering angle is acquired by multiplying the time-series data related to the azimuth angle deviation that has passed through the pass filter 29. The reference model steering angle acquired by the reference model steering angle acquisition unit 37 is sent to the reference model error calculation unit 39.

As shown in FIG. 5, the reference model error calculation unit 39 is based on the actual steering angle data sent from the steering angle sensor 17 and the reference model steering angle data acquired by the reference model steering angle acquisition unit 37. It has a function of calculating a “normative model error” that is an index representing the driver's arousal level. Specifically, the normative model error calculation unit 39 calculates a “normative model error” by obtaining a difference between the actual steering angle data and the normative model steering angle data. The “normative model error” calculated by the normative model error calculating unit 39 is sent to the arousal level estimating unit 41.
The reference model error calculation unit 39 calculates a “reference model error” by obtaining a difference between the actual steering angle data and the reference model steering angle data and performing a mean square process on the obtained difference data. A configuration may be adopted.

The arousal level estimation unit 41 estimates the driver's arousal level based on the “residual” calculated by the residual calculation unit 33 or the “standard model error” calculated by the standard model error calculation unit 39. It has a function. Information on the arousal level estimated by the arousal level estimation unit 41 is sent to the alarm control unit 43.
The arousal level estimation unit 41 corresponds to the “driver state estimation unit” of the present invention.

  The alarm control unit 43 has a function of performing alarm control for causing the speaker 19 to generate an alarm sound when the arousal level information indicating that the driver's arousal level is below a predetermined level is sent from the arousal level estimation unit 41. Have

[Operation of Awakening Level Estimation Device 11 According to Embodiment of the Present Invention]
Next, the operation of the arousal level estimation apparatus 11 according to the embodiment of the present invention will be described with reference to FIGS. 6A, 6B, and 7. FIG. 6A is a flowchart showing the flow of the normative model setting process among the operations of the arousal level estimation apparatus 11 according to the embodiment of the present invention. FIG. 6B is a flowchart showing the flow of the arousal level estimation process among the operations of the awakening level estimation device 11. FIG. 7 is an explanatory diagram illustrating the relationship of the arousal level with respect to the normative model error.

  Note that the normative model setting process shown in FIG. 6A is performed when, for example, the normative model is not set or when another normative model is already set even if the normative model has already been set (for example, the vehicle Ca A plurality of drivers and a specific reference model is set for each of these drivers). 6A and 6B include processing steps common to both (see steps S501 to S504). Therefore, in FIG. 6A and FIG. 6B, common step numbers are assigned between the processing steps common to both, and redundant description thereof is omitted.

  In step S501, the target azimuth angle acquisition unit 21 recognizes the direction of the white line by performing image processing on the image information of the road surface including the white line sent from the imaging unit 13, and recognizes the direction of the recognized white line. Based on the amount of deviation in the yaw direction from the direction of the longitudinal axis of the vehicle body, a target azimuth, which is an operation target value of the driver, is calculated and acquired.

  In step S <b> 502, the actual azimuth angle acquisition unit 23 acquires the actual azimuth angle that is the actual operation amount of the vehicle Ca by integrating the yaw rate over a predetermined time detected by the yaw rate sensor 15.

  In step S503, the azimuth deviation calculation unit 25 calculates an azimuth deviation that is the difference between the target azimuth obtained in step S501 and the actual azimuth obtained in step S502.

  In step S504, the steering angle sensor 17 detects and acquires the actual steering angle of the steering wheel 18 operated by the driver.

  In step S505, the driver model creation unit 27 defines the input / output relationship of the driver with the azimuth angle deviation calculated in step S503 as the driver's input and the actual steering angle acquired in step S504 as the driver's output. The driver model is created by calculation by applying Equation (3).

  In step S506, the normative model setting unit 35 determines whether or not the driver model created in step S505 is created using standard data. Here, the standard data is data belonging to a range widely used as input and output for the driver. Specifically, the standard data relates to the driver's input and output when “the amount of change in the actual steering angle per unit time is below a predetermined value and the state continues for a predetermined time”. It is data.

  Here, “when the amount of change in the actual steering angle per unit time is below a predetermined value and this state continues for a predetermined time” means that the driver is operating the steering wheel 18 suddenly. A state in which there is no state (a state in which the amount of change in the actual steering angle per unit time is a predetermined value or less) continues for a predetermined time. Specifically, for example, a scene in which the vehicle Ca continues running on a straight road (for example, traveling straight on a straight highway) may be assumed. The driver model created in such a scene is considered to be versatile with no wrinkles.

  In short, in the present embodiment, the reference model setting unit 35 creates the driver model created in step S505 in a scene where the vehicle Ca continues running on a straight road (for example, straight ahead on a straight highway). Based on whether or not the driver model is set, it is determined whether or not the driver model is created using standard data.

  As a result of the determination in step S506, when it is determined that the driver model created in step S505 is not created using standard data (“No” in step S506), the norm model setting unit 35 Returns the processing flow to step S501 to perform the following processing. In this case (“No” in step S506), the reference model setting unit 35 does not set the reference model.

  On the other hand, as a result of the determination in step S506, if it is determined that the driver model created in step S505 is created using standard data (“Yes” in step S506), the reference model The setting unit 35 advances the process flow to the next step S507.

  In step S507, the norm model setting unit 35 sets the driver model created in step S505 as a norm model that is a driver model serving as a norm suitable for repeated use. When the reference model setting process in step S507 ends, the ECU 20 ends the flow of a series of processes.

Next, the arousal level estimation process illustrated in FIG. 6B is performed, for example, when an activation switch (not illustrated) of the arousal level estimation device 11 is turned on.
Note that the processing steps of steps S501 to S504 are the same as those in FIG. 6A. For this reason, in FIG. 6B, the description of the processing steps of steps S501 to S504 is omitted, and the description of the processing contents is continued from step S511.

  In step S511, the normative model steering angle acquisition unit 37 applies the above-described equation (2) and performs bandpass for the driver model [K / (1 + Ts)] set as the normative model by the normative model setting unit 35. The reference model steering angle is obtained by multiplying the time-series data related to the azimuth angle deviation that has passed through the filter 29.

  In step S512, the reference model error calculation unit 39 calculates a “reference model error” by obtaining a difference between the actual steering angle data acquired in step S504 and the reference model steering angle data acquired in step S511.

  In step S 513, the arousal level estimation unit 41 estimates the driver's arousal level, which is one mode of the driver state, based on the “normative model error” calculated by the standard model error calculation unit 39. This estimation is performed in the following procedure, for example.

  That is, first, the size of the “normative model error” is set in five levels (ER1 / ER2 / ER3 / ER4 / ER5; see FIG. 7) in ascending order. On the other hand, the level of arousal level is changed from 5 in the order of high arousal level (for example, the order of not sleeping) (AW1 (not sleeping at all) / AW2 (somewhat sleepy) / AW3 (sleepy) / AW4 (very sleepy) / AW5 ( Very sleepy); see FIG. Based on the above setting contents, as shown in FIG. 7, a relationship table is prepared in which ER1 is associated with AW1, ER2 is associated with AW2, ER3 is associated with AW3, ER4 is associated with AW4, and ER5 is associated with AW5.

  The awakening level estimation unit 41 identifies which stage of the ER1 to ER5 the “normative model error” calculated by the normative model error calculation unit 39 belongs to, and thus the identified “normative model error” stage. The corresponding level of alertness (assuming that it is “AW4 (very sleepy)”) is adopted as the driver's alertness.

  In step S514, the warning control unit 43 satisfies the predetermined condition (assuming that the level of arousal level is AW4 or AW5) in the level of arousal level (AW4) estimated in step S513. It is determined whether or not.

  As a result of the determination in step S514, when it is determined that the arousal level estimated in step S513 does not satisfy the predetermined condition (“No” in step S514), the alarm control unit 43 The flow is caused to jump to step S516.

  On the other hand, as a result of the determination in step S514, when it is determined that the arousal level estimated in step S513 satisfies a predetermined condition (“Yes” in step S514), the alarm control unit 43 The process flow proceeds to the next step S515. In this embodiment, the level of arousal estimated in step S513 is “AW4 (very sleepy)”, and the predetermined condition is “the level of arousal is AW4 or AW5”. Makes a determination that the level of arousal level estimated in step S513 satisfies a predetermined condition, and advances the flow of processing to the next step S515.

  In step S515, the alarm control unit 43 causes the speaker 19 to generate an alarm sound. As a result, the alarm is continuously emitted from the speaker 19 to the driver for a predetermined time (for example, 5 seconds).

  In step S515, the ECU 20 checks whether the activation switch of the arousal level estimation device 11 is on. When the activation switch of the arousal level estimation device 11 is turned on (“No” in step S516), the ECU 20 returns the process flow to step S501 and performs the following arousal level estimation process. On the other hand, when the activation switch of the arousal level estimation device 11 is turned off (“Yes” in step S516), the ECU 20 ends the processing flow.

[Operational effect of the arousal level estimation apparatus 11 according to the embodiment of the present invention]
In the arousal level estimation apparatus 11 according to the embodiment of the present invention, the target azimuth angle obtaining unit 21 describes a driver's target azimuth angle (operation target value; however, the terms in the corresponding claims are described in parentheses. The same shall apply hereinafter). The actual azimuth angle acquiring unit 23 acquires the actual azimuth angle (actual operation amount) of the vehicle Ca based on the integrated value of the yaw rate detected by the yaw rate sensor 15. The steering angle sensor 17 functioning as an actual operation amount acquisition unit of the present invention acquires the driver's actual steering angle (actual operation amount). The reference model setting unit 35 uses a driver's input as an azimuth angle deviation that is a difference between a target azimuth angle (operation target value) and an actual azimuth angle (actual motion amount), and sets the actual steering angle (actual operation amount) as the driver's input. As an output, a driver model that defines the input / output relationship of the driver and that serves as a norm suitable for repeated use is set as a norm model. The reference model steering angle acquisition unit 37 inputs the azimuth angle deviation, which is the difference between the target azimuth angle (operation target value) and the actual azimuth angle (actual movement amount), into the reference model, thereby allowing the reference model steering angle (reference model operation amount). ) To get. Then, the arousal level estimation unit 41 is based on a normative model error obtained from a difference between the actual steering angle (actual operation amount) and the normative model steering angle (normative model operation amount). Estimate the degree of arousal.

According to the study by the present inventors, the function required for the driver model is a function that outputs the driver model steering angle (driver model operation amount) when the azimuth deviation is input, and repeats a certain driver model. Even if it is used, it has been found that as long as the driver model is set appropriately, there is a high probability that the estimation accuracy of the arousal level is not impaired.
Therefore, the arousal level estimation apparatus 11 according to the embodiment of the present invention may adopt a configuration in which a driver model serving as a norm suitable for repeated use is set as a norm model and this norm model is used repeatedly.

The driver model set as the reference model is a driving component that is a component of the arousal level estimation device 11 mounted on the vehicle Ca on the condition that a driver model that is a reference suitable for repeated use is set as the reference model. It does not matter whether it is created by the person model creation unit 27 or so-called offline.
According to the arousal level estimation apparatus 11 according to the embodiment of the present invention, it is possible to reduce the load related to information processing related to the sequential creation of a driver model and to increase the speed of the estimation process as a whole.

  The arousal level estimation apparatus 11 according to the embodiment of the present invention further includes a driver model creation unit 27 that creates a driver model, and the reference model setting unit 35 is created by the driver model creation unit 27 in the past. A configuration may be adopted in which a driver model serving as a norm suitable for repeated use is set as a norm model from among the driver models.

  According to the arousal level estimation apparatus 11 according to the embodiment of the present invention, in addition to the effect of reducing the load related to information processing and increasing the speed of the estimation process as a whole, the reference model can be easily set. Moreover, if the driver model and the driver are the same, if the awakening level estimation device 11 is used, an improvement in accuracy related to the awakening level estimation can be expected.

  In the arousal level estimation apparatus 11 according to the embodiment of the present invention, the normative model setting unit 35 is created by the driver model creating unit 27 using standard data belonging to a range widely used as the driver's input and output. A configuration may be adopted in which the driver model is set as the reference model.

  According to the arousal level estimation apparatus 11 according to the embodiment of the present invention, in addition to the effect of reducing the load related to information processing and increasing the speed of the estimation process as a whole, the attribute (driving) of the driver that is the target of the arousal level estimation Whether the driver is the same as the driver model, whether it is a beginner or an expert in the case of a driver different from the driver model) An estimation process can be performed.

  In the arousal level estimation apparatus 11 according to the embodiment of the present invention, the driver's input is an azimuth deviation that is a difference between the target azimuth and the actual azimuth, and the driver's output is the actual steering of the vehicle Ca. Standard data is data related to driver input and output when the amount of change in the actual steering angle per unit time is below a predetermined value and the state continues for a predetermined time. A configuration may be adopted.

  According to the arousal level estimation apparatus 11 according to the embodiment of the present invention, the specific requirements of the standard data when the azimuth deviation is used as the driver's input are defined. In addition to the effects related to high speed as a whole, the reference model can be set accurately.

  Moreover, in the arousal level estimation apparatus 11 which concerns on embodiment of this invention, the target azimuth angle acquisition part 21 is a driver | operator's target based on the advancing direction information of the vehicle Ca obtained by the yaw rate sensor 15 (azimuth angle acquisition apparatus). You may employ | adopt the structure which acquires an azimuth (operation target value).

  In the arousal level estimation apparatus 11 according to the embodiment of the present invention, the driver's input is a vehicle position deviation that is the difference between the target vehicle position and the actual vehicle position, and the driver's output is the actual steering of the vehicle Ca. Standard data is data related to driver input and output when the amount of change in the actual steering angle per unit time is below a predetermined value and the state continues for a predetermined time. A configuration may be adopted.

  According to the arousal level estimation apparatus 11 according to the embodiment of the present invention, the specific requirements of the standard data when the vehicle position deviation is used as the driver's input are defined. In addition to the effects related to high speed as a whole, the reference model can be set accurately.

  Further, in the awakening level estimation device 11 according to the embodiment of the present invention, the operation target value acquisition unit 21 is the travel lane position information of the vehicle Ca obtained through the imaging unit 13 (position information of the white line that divides the travel lane). Based on the above, a configuration may be adopted in which the driver's operation target value (target azimuth / target vehicle position) is acquired.

  According to the arousal level estimation apparatus 11 according to the embodiment of the present invention, since the configuration using the traveling lane position information of the vehicle Ca as the acquisition route related to the operation target value of the driver is adopted, it is possible to reduce the load related to information processing and In addition to the effect of speeding up the estimation process as a whole, the operation target value can be accurately acquired.

  Further, the operation target value acquisition unit 21 acquires the driver's operation target value (target azimuth / target vehicle position) based on road information related to the traveling direction of the vehicle Ca obtained from a navigation device (not shown). The configuration may be adopted.

As a navigation device, for example, it has a positioning function by autonomous navigation and a positioning function by satellite navigation using a GPS (Global Positioning System) receiver. An in-vehicle navigation device having a detection function is used. The target azimuth angle acquisition unit 21 can acquire the target azimuth angle and target vehicle position (operation target value) of the driver based on road information relating to the traveling direction of the vehicle Ca obtained via the navigation device.
In addition, if the positioning function by satellite navigation using a DGPS (Differential Global Positioning System) receiver is used, positioning accuracy can be improved.

  According to the arousal level estimation device 11 according to the embodiment of the present invention, a configuration is adopted in which road information related to the traveling direction of the vehicle Ca obtained through the navigation device is used as the acquisition route related to the operation target value of the driver. Therefore, in addition to the effect of reducing the load related to information processing and increasing the speed of the estimation process as a whole, it is possible to accurately acquire the operation target value.

[Other Embodiments]
The embodiment described above shows an embodiment of the present invention. Therefore, the technical scope of the present invention should not be limitedly interpreted by these. This is because the present invention can be implemented in various forms without departing from the gist or main features thereof.

  For example, when a so-called offline created driver model is set as a reference model, the driver model creating unit 27, the driver model steering angle obtaining unit 31, and the residual calculation included in the ECU 20 of the arousal level estimation device 11 The part 33 can be omitted.

  In the description of the embodiment according to the present invention, the target azimuth is exemplified as the operation target value, but the present invention is not limited to this example. As the operation target value, a target displacement amount that is a target value of the displacement amount with respect to the horizontal direction of the white line may be used. In this case, the actual operation amount may be replaced with the actual displacement amount, and the actual operation amount may be replaced with the actual steering angle.

In the description of the embodiment according to the present invention, the ECU 20 included in the arousal level estimation device 11 includes, as logical components (software), a target azimuth angle acquisition unit 21, an actual azimuth angle acquisition unit 23, and an azimuth angle deviation calculation. Unit 25, driver model creation unit 27, bandpass filter 29, driver model steering angle acquisition unit 31, residual calculation unit 33, reference model setting unit 35, reference model steering angle acquisition unit 37, reference model error calculation unit 39 Although an example having the arousal level estimation unit 41 and the alarm control unit 43 has been described, the present invention is not limited to this example.
These various functional units 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, and 43 may be configured by hardware.

  Further, in the description of the embodiment according to the present invention, the example of setting the arousal level to five levels has been described, but the present invention is not limited to this example. The awakening level can be set to any number of levels.

  In the description of the embodiment according to the present invention, the alarm control unit 43 has been described with an example in which the speaker 19 generates an alarm sound when the arousal level satisfies a predetermined condition. The invention is not limited to this example. The warning that promotes the driver's awakening may employ a mode in which the driver's vision, touch, or smell is stimulated in addition to hearing. Moreover, you may employ | adopt the aspect which stimulates several combinations simultaneously among a driver | operator's auditory sense, visual sense, tactile sense, or olfactory sense.

  Finally, in the description of the present embodiment, the wakefulness estimation device 11 has been described as an example for realizing the driver state estimation device according to the present invention, but the present invention is not limited to this example. . The driver state estimation device according to the present invention uses all the functions that estimate the state of a driver who is performing a nap driving, drunk driving, aside driving, random driving, etc., using the concept of a normative model. This is because it is a comprehensive concept.

11 Arousal level estimation device (driver state estimation device)
13 Imaging unit 15 Yaw rate sensor (azimuth angle acquisition device)
17 Steering angle sensor (actual operation amount acquisition unit)
18 Steering wheel 19 Speaker 20 ECU
21 Target azimuth angle acquisition unit (operation target value acquisition unit)
23 Real azimuth angle acquisition unit (actual movement amount acquisition unit)
25 Azimuth Deviation Calculation Unit 27 Driver Model Creation Unit 29 Band Pass Filter 31 Driver Model Steering Angle Acquisition Unit (Driver Model Operation Amount Acquisition Unit)
33 residual calculation unit 35 reference model setting unit 37 reference model steering angle acquisition unit (reference model operation amount acquisition unit)
39 Reference model error calculation unit 41 Arousal level estimation unit (driver state estimation unit)
43 Alarm control unit

Claims (6)

A driver state estimating device for estimating a state of a driver driving a vehicle,
An operation target value acquisition unit for acquiring the operation target value of the driver;
An actual operation amount acquisition unit for acquiring an actual operation amount of the vehicle;
An actual operation amount acquisition unit for acquiring the actual operation amount of the driver;
Driver model creation that creates a driver model that defines the input / output relationship of the driver, using the difference between the operation target value and the actual operation amount as a driver input, and using the actual operation amount as the driver output. And
Among the driver models created in the past by the driver model creation unit, a normative model setting unit that sets a driver model serving as a norm suitable for repeated use as a normative model;
Said used repeatedly to set the reference model, the operation target value and the difference of the actual operation amount to obtain the reference model manipulated variable by inputting to the reference model reference model operation amount acquisition unit,
A driver state estimating unit that estimates a driver's state based on a reference model error obtained from a difference between the actual operation amount and the reference model operation amount;
A driver state estimation device comprising: The driver state estimating device according to claim 1 ,
The normative model setting unit sets, as the normative model, the driver model created by the driver model creating unit using standard data belonging to a range widely used as the driver input and output.
A driver state estimation device characterized by the above. The driver state estimation device according to claim 2 ,
The driver's input is the difference of the target azimuth with respect to the actual azimuth,
The driver's output is expressed by the actual steering angle of the vehicle,
The standard data is data relating to the input and output of the driver when the change amount of the actual steering angle per unit time is in a state equal to or less than a predetermined value and the state continues for a predetermined time.
A driver state estimation device characterized by the above. The driver state estimation device according to any one of claims 1 to 3 ,
The operation target value acquisition unit acquires the driver's operation target value based on traveling direction information of the vehicle obtained by an azimuth angle acquisition device.
A driver state estimation device characterized by the above. The driver state estimation device according to claim 2 ,
The driver's input is the difference of the target vehicle position with respect to the actual vehicle position,
The driver's output is expressed by the actual steering angle of the vehicle,
The standard data is data relating to the input and output of the driver when the change amount of the actual steering angle per unit time is in a state equal to or less than a predetermined value and the state continues for a predetermined time.
A driver state estimation device characterized by the above. The driver state estimation device according to claim 5 ,
The operation target value acquisition unit acquires the driver's operation target value based on travel lane position information of the vehicle obtained via the imaging unit.
A driver state estimation device characterized by the above.

Images