JP2006248444A - Travel controller and travel control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of attaining proper control for relieving the influence of cross wind when fanned by the cross wind. <P>SOLUTION: This travel controller allows a travel position monitor unit 106 to detect marker information, such as a white line on a road, and a vehicle central processing unit 101 to calculate a reference traveling line as an estimated traveling line along which the vehicle is going to travel. It calculates an affected estimated traveling line when a sensor 102 for the direction of wind and the force of the wind detects the cross wind. Then, this travel controller compares the two traveling lines and calculates a displacement amount in between, and then calculates a steering angle δ so that the displacement amount may become lower than predetermined value, to activate a steering angle control motor 105. This enables the steering controller to perform the steering control, on detecting the cross wind, at an early time before the influence of the cross wind completely reaches the travel of the vehicle, thus suppressing an unsteady behavior of the vehicle from being caused by the cross wind. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for automatically controlling a steering angle by detecting a cross wind received by a traveling vehicle.

  2. Description of the Related Art A vehicle travel control system for performing safe and stable travel is known. For example, Patent Document 1 discloses a system that automatically controls traveling while recognizing a white line on a road with a CCD camera. Japanese Patent Application Laid-Open No. 2004-228561 describes a technique that detects a position marker embedded in a road, calculates a lateral position of the vehicle on the road, and helps to prevent lane departure.

  In addition, as a technique for steering along the reference line on the road using magnetic markers embedded in the road, the trajectory to be traced by the vehicle is changed in the vehicle width direction to reduce the burden on the road. Patent Document 3 describes a technique for preventing the formation of wrinkles. Further, Patent Document 4 describes a technique for grasping a vehicle positional relationship on a road by using GPS information and performing speed control and inter-vehicle distance control.

  Patent Document 5 describes a technique for automatically controlling the acceleration / deceleration state when a crosswind is received during traveling so that the vehicle behavior does not become unstable. Further, Patent Document 6 describes a configuration in which, in a dozing driving alarm device, a driver's state with respect to environmental changes is determined, and an alarm is issued when it is determined that the driver is dozing. Patent Document 6 describes a crosswind sensor as means for detecting a disturbance, and describes an automatic travel mode using various types of sensing information.

JP-A-10-247300 JP 2000-260156 A JP-A-9-62346 JP 2000-222491 A Japanese Patent Laid-Open No. 2004-314849 JP-A-6-156262 (paragraphs 0037 and 0048)

  It is well known that the traveling line of a vehicle is shifted suddenly due to a crosswind immediately after the traveling vehicle exits the tunnel or passes through a river bridge. In order to drive the vehicle safely, even if the driving line is shifted suddenly due to crosswinds, the degree of concentration that instantly recognizes the deviation, and the reflection ability to maintain the driving line by correcting the deviation within a short time Steering skills accompanied with For this reason, it is also known that a driver of a vehicle traveling on a highway is forced to be overtensioned.

  Furthermore, in order to drive a vehicle comfortably in addition to driving a safe vehicle, the driver is also required to have the ability to display the environment of the road on which the vehicle is driven by road signs and to predict crosswinds based on it. . For example, cognitive ability, reflex ability, and steering skills are required to minimize the amount of deviation in the running line even when sudden crosswinds occur, and in addition, steering angle adjustment skills based on prediction ability and experience Will also be required.

  The above-described conventional technology is a technology related to control for realizing safe and comfortable driving in a technology that assists the steering of the driver or automatically controls the driving of the vehicle. In terms of proper steering control when sudden crosswinds were received, it was not sufficient. For example, Patent Document 6 describes a point in which crosswind is sensed as disturbance in automatic driving, but it is not clarified how to process crosswind information and use it in automatic driving. .

  Therefore, the present invention provides a technique for performing control with high steering accuracy that can reduce deviation of a travel line of a vehicle when the vehicle is suddenly subjected to a crosswind in traveling in which the steering of the vehicle is automatically controlled. With the goal.

  A travel control device according to the present invention includes a travel position monitoring unit that detects markers placed on a road and outputs marker information, a reference travel line calculation unit that calculates a reference travel line based on the marker information, and a vehicle body A crosswind detecting means for detecting a crosswind against the wind, an expected travel line calculating means for calculating an expected travel line affected by the crosswind, the reference travel line and the predicted travel line are compared, and a reference travel of the expected travel line A shift amount calculating means for calculating a shift amount from the line and a steering angle calculating means for calculating a steering angle for making the shift amount equal to or less than a predetermined value are provided.

  In the present invention, the reference travel line is a future travel route on which the vehicle travels, which is acquired from marker information such as a white line on the road, and a travel line obtained by translating this route in the vehicle width direction by a predetermined amount as necessary. Is defined as

  According to the above invention, the reference travel line that is the future travel route on which the vehicle should travel is calculated from the marker information such as the white line on the road, and when the crosswind is detected, the expected travel line that is affected is calculated. Is done. Then, the amount of deviation between the two travel lines is calculated by comparing the two travel lines. Then, the steering angle is calculated so that the deviation amount is equal to or less than a predetermined value. By performing the steering control of the steering angle, the steering control is performed at an early stage (or as early as possible even if there is an influence of the cross wind) when the cross wind is detected. Therefore, the unstable behavior of the vehicle due to crosswind is suppressed.

  In addition, since the reference driving line is acquired by detecting markers placed on the road, the influence of crosswinds is always based on the future course that the vehicle should always travel even if the road is curved or winding. The steering angle can be controlled in consideration of the above.

  In addition, this method can always confirm the course to go by detecting the marker, so in the event of a strong gust of wind or strong crosswind, there is no loss of sight of the course to go on, and the criteria have always been clarified. Control can be performed.

  As an amount of deviation of the predicted travel line from the reference travel line, an angle between the two lines, a distance between the lines, and an amount that can quantitatively evaluate that the two lines do not match can be employed.

  The marker information refers to information on a line (for example, a line represented by a white line such as a conventional center line) indicated by the marker by processing a signal in which the marker is detected. From this marker information, for example, the relative positional relationship between the position of the center line of the road and the vehicle (vehicle equipped with the system using the present invention) can be calculated.

  As the cross wind detecting means, there can be mentioned a configuration in which the wind receiving body detects that the wind receiving body is tilted by a strain gauge and calculates the wind direction and the wind force from the detection signal.

  In the travel control device of the present invention, it is preferable that the predicted travel line calculation means performs control to perform calculation in consideration of the deviation of the actual travel line from the reference travel line. According to this aspect, the state in which the vehicle deviates from the reference travel line due to factors other than crosswind is quantitatively grasped, and the influence is reflected in the calculation result of the predicted travel line. Therefore, in a situation where the traveling direction of the vehicle deviates from the reference traveling line due to the influence other than the crosswind, the steering angle is automatically corrected and the deviation is corrected.

  In the travel control device of the present invention, it is preferable that the cross wind detecting means is attached to the front portion of the vehicle. In the present invention, after the crosswind actually affects the movement of the vehicle, the control is not performed, but the process is started when the crosswind is detected. In order to effectively obtain this action, it is important to provide a cross wind detecting means in the portion of the vehicle where the cross wind first collides. This preferred state can be realized by attaching the cross wind detecting means to the front part of the vehicle.

  Examples of the marker in the travel control device of the present invention include a white line drawn on the road or a magnetic marker arranged on the road. When the white line is used as a marker, an example can be given in which a white line is imaged using an imaging device such as a CCD camera, and a travel line is detected by image processing.

  As a magnetic marker, the structure by the magnet arrange | positioned on the road (or buried in the road) at predetermined intervals can be mentioned. In this case, the traveling position monitoring means detects the marker information by detecting the magnetism of the magnet. Examples of the marker include an appropriate pattern display on the road, a display with a special paint, and a device that reacts to electromagnetic waves as used in an IC card. The traveling position monitoring means may detect information (for example, image information or magnetic information) according to the marker mode.

  The mechanism of the traveling control device of the present invention can also be grasped as a traveling control method. That is, the travel control method of the present invention detects a marker placed on the road, obtains marker information, a marker information acquisition step, a reference travel line calculation step that calculates a reference travel line based on the marker information, A crosswind detection step for detecting a crosswind with respect to the vehicle body, a predicted travel line calculation step for calculating an expected travel line affected by the crosswind, and the reference travel line and the predicted travel line are compared, and a reference for the predicted travel line A deviation amount calculating step for calculating a deviation amount from the travel line, and a steering angle calculating step for calculating a steering angle for making the deviation amount equal to or less than a predetermined value are provided.

  According to the present invention, a reference travel line calculated based on a marker arranged on a road is used as a reference, and this is compared with an expected travel line expected to be generated as a result of the influence of crosswind. Then, the steering angle is adjusted so that the deviation between the reference travel line and the expected travel line is eliminated. For this reason, the reference | standard driving | running line along the road which is always drive | working can be made into the reference | standard of correction | amendment. In this way, it is possible to provide appropriate control that can reduce the influence of a crosswind.

(1) Configuration of Embodiment FIG. 1 is a block diagram showing an outline of a travel control device using the invention. A travel control apparatus 100 shown in FIG. 1 includes a vehicle central processing unit 101, a wind direction / wind force sensor 102, a wind direction / wind force calculation unit 103, a steering angle control unit 104, a steering angle control motor 105, and a travel position monitoring unit 106. Yes.

  The vehicle central processing unit 101 has a function of executing a processing procedure described later. The vehicle central processing unit 101 includes a CPU, a ROM, a RAM, an interface for exchanging information with other units, and the like. The ROM stores a control program for processing to be described later, various data necessary for performing control, calculation formulas, and the like. The RAM has a function of temporarily storing data in a row as described later.

  The wind direction / wind force sensor 102 is a sensor that detects the direction of wind hitting the vehicle body and the wind force. Examples of the wind direction / wind force sensor 102 include a structure that detects the movement of the wind receiving body with a strain gauge. The sensor having this structure detects wind force from the inclination of the wind receiving body and detects the wind direction from the direction in which the wind receiving body is inclined.

  The wind direction / wind force calculation unit 103 has a function of processing an output signal of the wind direction / wind force sensor 102 and generating a wind direction value signal and a wind force value signal. For example, when the wind direction / wind force sensor using the strain gauge described above is employed, the wind direction / wind force calculation unit 103 performs a process of calculating the wind direction and the wind force from changes in voltage values in the plurality of strain gauges.

  The steering angle control unit 104 receives the signal of the corrected steering angle δ calculated by the vehicle central processing unit 101, and generates a control signal for causing the steering angle control motor 105 to perform steering based on the steering angle. The steering angle control motor 105 is a drive motor that controls the steering angle. For example, steering is performed by controlling the direction of the rotation axis of the front wheels. In this case, the motor that controls the direction of the rotation axis of the front wheel is the steering angle control motor 105. The steering method is not limited to this example, and various forms can be adopted.

  The traveling position monitoring unit 106 has a function of detecting markers on the road. For example, as a travel position monitoring unit, there is a mechanism in which a white line or display on a road is imaged by a CCD camera, and data (travel position information) for specifying its travel position with respect to the white line is output as marker information by image analysis. Can do. Further, the traveling position monitoring unit 106 may include a mechanism that detects a magnetic marker embedded in a road and outputs data obtained by analyzing the detected data as data (traveling position information) for specifying its traveling position.

  In this configuration, the vehicle central processing unit 101 calculates a reference travel line based on travel position information from the travel position monitoring unit 106 based on a white line or a magnetic marker. The reference travel line refers to a travel line to be traced by a moving vehicle.

  Further, the wind direction / wind power calculation unit 103 is based on the signal from the wind direction / wind sensor 102, for example, the angle with the traveling direction of the vehicle body (specifically, values such as 10 degrees to the right and 7 degrees to the left). ) And the wind power F are output to the vehicle central processing unit 101.

  When the component Fx of the wind force F with respect to the lateral direction of the vehicle body is small, the frictional force between the tire and the road surface is excellent, so that unintended vehicle body movement in the lateral direction is not a problem. However, if Fx exceeds the allowable value, unintended vehicle body movement in the lateral direction occurs, and the vehicle body tends to deviate from the reference travel line. In the above configuration, when the cross wind is detected, the steering angle is controlled so as to suppress the influence thereof, so that the movement of the above-described vehicle body that tends to be off the reference travel line can be suppressed. This has a high effect of suppressing the unstable behavior of the vehicle body as compared to the case where the vehicle body is actually moved in the lateral direction and the correction control is performed.

  FIG. 2 is a schematic diagram showing the arrangement positions of sensors in an example of a passenger car. As shown in FIG. 2, the wind direction / wind force sensor 102 is preferably disposed in front of the vehicle body 201. Thereby, the influence of a cross wind can be detected at the earliest possible timing. The traveling position monitoring unit 106 may be disposed at a position where the marker on the road is easy to detect, for example, at the lower part in front of the vehicle body.

(2) Operation of Embodiment FIG. 3 is a flowchart showing an example of the operation of the travel control device shown in FIG. When it is detected that the vehicle has started to run and exceeds a predetermined speed (for example, 25 km / h), the control shown in FIG. 3 is started. When the control is started, two systems of processes of steps S101 to S105 executed in the vehicle central processing unit 101 and steps S106 and S107 executed in the traveling position monitoring unit 106 are executed in parallel.

  That is, the vehicle central processing unit 101 determines whether marker information can be acquired by the function of the traveling position monitoring unit 106 (see FIG. 1) (step S101). If the marker information can be acquired, the marker information is displayed. Obtain (step S103).

  Next, based on the acquired marker information (travel position information), a reference travel line is calculated (step S104), and the process proceeds to step S105. When marker information cannot be acquired (for example, when driving on a road on which no marker is arranged), a reference driving line prepared in advance is set (step S102), and the process proceeds to step S105. In the present embodiment, the reference travel line set in step S102 is, for example, a straight line.

  When the reference travel line is obtained in step S104 or step S102, a deviation Ax between the reference travel line and the actual travel line where the vehicle is actually going to travel is calculated (step S105). Here, the actual travel line may be obtained based on the reference travel line. For example, when the reference travel line detected by the travel position monitoring unit 106 gradually shifts to the right, it is recognized that the vehicle is moving in a direction deviating to the left relative to the reference travel line. Is done. Ax can be calculated by quantitatively evaluating the time change of the deviation.

  For example, Ax is obtained as an angle formed between the reference travel line and the actual travel line and a distance separating the reference travel line and the actual travel line.

  Simultaneously with the processing of steps S101 to S105, the wind direction / wind force calculation unit 102 acquires the value of the wind direction and the wind force (step S106), and further calculates the lateral component Fx of the wind force with respect to the vehicle body based on the values. (Step S107).

After calculating Ax and Fx, the vehicle central processing unit 101 executes the following steps S108 to S113. First, in step S108,
(First state): Ax> allowable value, Fx> allowable value,
(Second state): Ax ≦ allowable value, Fx> allowable value,
(Third state): Ax> allowable value, Fx ≦ allowable value,
(Fourth state): Ax ≦ allowable value, Fx ≦ allowable value,
Is judged.

  Here, the first state is a state where the deviation from the reference travel line is larger than the allowable value, and at the same time the cross wind is stronger than the allowable value. The second state is a state in which the deviation from the reference travel line is equal to or less than an allowable value (that is, the vehicle can be regarded as running on the reference travel line), but the cross wind is stronger than the allowable value. The third state is a state in which the deviation from the reference travel line is larger than the allowable value, but the cross wind is less than the allowable value. The fourth state is a state in which the deviation from the reference travel line is less than the allowable value and the cross wind is less than the allowable value.

  If the first state is determined, an expected travel line that considers Ax and Fx is calculated (step (S109)). If the second state is determined, Ax is not considered, and an prediction that considers only Fx is calculated. When a travel line is calculated (step S110) and the third state is determined, only Ax is considered and an expected travel line not considering Fx is calculated (step S111), and the fourth state is determined The expected driving line is not calculated.

  When the predicted travel line is calculated in step S109, step S110, or step S111, the predicted travel line is compared with the reference travel line (obtained in S104 or S102), and the difference (deviation amount φ) is calculated. (Step S112). For example, the shift amount φ is grasped as an angle between two travel lines and a distance between the two travel lines.

  As a method of reflecting the horizontal component Fx of wind force (transverse component with respect to the traveling direction of the vehicle body) on the predicted travel line, a method using a calculation formula, a method using table data based on experimental data acquired in advance, these The method of combining these is mentioned. Further, since the wind direction and wind sensor 103 (see FIG. 1) detects the force applied to the wind receiving body of the sensor, there is also a method of obtaining the wind speed from the wind speed and obtaining the predicted travel line using this wind speed data.

  After calculating the deviation amount φ, the correction steering angle δ is calculated so that φ ≦ allowable value (step S113). When the corrected steering angle δ is calculated, the steering angle control unit 104 outputs a command signal for realizing the corrected steering angle δ to the steering angle control motor 105 (step S114). Steering control is performed by this command signal. It should be noted that the above tolerance value for determining the range of φ may be appropriately selected according to the traveling speed, road surface condition, and the like.

  Next, in step S115, it is determined whether or not the control is OFF. If the control is not OFF, the process returns to step S101, and a series of processing is repeated. If the control is OFF, the control is terminated. If it is determined in step S108 that the state is the fourth state (Ax ≦ allowable value, Fx ≦ allowable value), the correction steering angle is not calculated, and the process proceeds to step S115.

  As a condition for determining YES in step S115, for example, when the vehicle traveling speed is 25 km / h or lower, when the control is manually turned off, the direction indicator is operated, and the intentional steering angle by the steering wheel operation is determined. Examples include cases where control is performed.

  According to the control shown in FIG. 3, in addition to performing automatic steering angle control so that driving is performed along a marker installed on the road, automatic steering angle control in consideration of the influence of cross wind is performed. According to this control, for example, the steering angle control is performed so that the influence is reduced (or canceled) when a crosswind is received at the same time as the driving control along the line to be run set on the road is performed. It is possible to suppress unintended vehicle body movement in the lateral direction of the vehicle.

  In this control, the steering angle control can be instructed at the stage of receiving the side wind, so the steering angle is controlled in advance in anticipation of the vehicle body moving laterally after receiving the side wind. It can be carried out. For this reason, the unstable behavior of the vehicle body during traveling can be minimized. In addition, even if the steering angle is not corrected before it should deviate from the driving line that should have been automatically corrected (that is, it is not intended to move in the lateral direction), the steering angle is controlled early. Deviation can be minimized.

  In addition, since control is performed based on the reference travel line calculated based on the marker information, the correction reference can always be clearly defined, and the influence of crosswinds can be obtained without losing sight of the line to be traveled according to the road conditions. Considering the steering angle control can be performed.

  When the reference travel line based on the marker information is not used as a reference, there are portions where the technical effects described below are not sufficient. For example, let us consider a case where a vehicle body receives a momentary gust as a side wind while traveling on a road curved left and right like a road in a mountainous area. In this case, since the road itself is winding, in the automatic control of the steering angle in consideration of the influence of only the crosswind, the moving axis of the vehicle is deviated from the travel line on the road. Of course, this deviation is corrected by the driver's steering operation, but it is not sufficient in that “automatic control is performed so that the vehicle travels along the travel line on the road”.

  In the control shown in FIG. 3, the reference travel line acquired from the marker information on the road is used as the reference for the steering angle control. Therefore, even on a winding road as described above, it follows the bending condition of the road. Self-propelled steering angle control is performed. Therefore, on a winding road as described above, when a crosswind is applied, a steering angle control is performed so as to cancel the influence of the crosswind, and at the same time, a steering angle at which traveling along a winding road is performed. Control is performed.

  Note that the control shown in FIG. 3 can be applied even when the road does not include marker information. In this case, the determination in step S101 is NO, and a reference travel line prepared in advance is employed. In this case, the automatic steering angle control along the winding road as described above is not performed, but the steering angle control by detecting the cross wind is performed.

  In step S102 in this example, the example in which the straight line is set as the reference travel line has been described. However, in step S102, the extended shape of the road may be acquired from a GPS system or the like, and the reference travel line may be set based on the acquired shape.

  In step S108, Ax and Fx are adopted as parameters to be considered. However, in addition to this, it can also be used as a parameter that further considers the road inclination state (front-rear or left-right inclination state) and the like.

  Further, as the allowable value of Fx, a value corresponding to the curvature of the curve, the road surface condition of the road, the traveling speed, the weather, and the like can be adopted. In this case, Fx suitable for each condition can be used as appropriate, and the unstable behavior of the vehicle body during traveling can be effectively suppressed.

  The above description is an example in which the present invention is applied to a passenger car, but the type of the vehicle is not particularly limited. That is, the present invention can also be applied to buses and trucks. In particular, the present invention is effective for a vehicle type having a high vehicle height, a large area for receiving a side wind, and a large shift of a running line due to a sudden side wind.

  The present invention can be applied to vehicles such as passenger cars, trucks, and buses as a technology for realizing safe and comfortable automatic control traveling.

It is a block diagram which shows the outline | summary of the system of the traveling control apparatus using invention. It is a schematic diagram which shows the arrangement position of the sensor in the example of a passenger car. It is a flowchart which shows an example of the control procedure of the traveling control apparatus using invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Traveling control apparatus, 101 ... Vehicle central control unit, 102 ... Wind direction / wind power calculation unit, 103 ... Wind direction / wind force sensor, 104 ... Steering angle control unit, 105 ... Steering angle control motor, 106 ... Traveling position monitoring unit, 201 ... vehicles.

Claims (5)

A traveling position monitoring means for detecting markers placed on the road and outputting marker information;
Reference running line calculation means for calculating a reference running line based on the marker information;
Cross wind detection means for detecting cross wind with respect to the vehicle body;
An expected travel line calculating means for calculating an expected travel line affected by the cross wind;
A deviation amount calculating means for comparing the reference traveling line with the predicted traveling line and calculating a deviation amount of the predicted traveling line from the reference traveling line;
Steering angle calculation means for calculating a steering angle for making the deviation amount equal to or less than a predetermined value.   The travel control apparatus according to claim 1, wherein the predicted travel line calculation unit performs calculation in consideration of a deviation from an actual travel line from a reference travel line.   The travel control device according to claim 1, wherein the cross wind detecting means includes a wind receiving body attached to a front portion of the vehicle.   The travel control device according to claim 1, wherein the marker is a white line drawn on a road or a magnetic marker arranged on the road. A marker information acquisition step for detecting markers placed on the road and obtaining marker information;
A reference travel line calculation step for calculating a reference travel line based on the marker information;
A crosswind detection step for detecting crosswind to the vehicle body;
An expected travel line calculating step for calculating an expected travel line affected by the cross wind;
A deviation amount calculating step of comparing the reference travel line with the predicted travel line and calculating a shift amount of the predicted travel line from the reference travel line;
And a steering angle calculating step of calculating a steering angle for making the shift amount equal to or less than a predetermined value.

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