JP2009294446A - Travel support system and travel route curve creating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a travel support system for preventing reduction of the accuracy in controlling travel of a moving object. <P>SOLUTION: An input device 1 receives a plurality of measurement points indicated by position information on a three-dimensional space intermittently measured on a travel route where a moving object travels. A road map creation section 21 approximates, by using the position information indicating the measurement points received by the input device 1, each measurement point by a smooth curve on a three-dimensional space and creates a travel route curve representing the travel route. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a travel support system and a travel path curve generation method for controlling travel of a moving body.

  In recent years, a driving support system that supports driving of a moving body such as an automobile has been proposed or put into practical use. In the travel support system, travel control information for controlling the travel of the mobile object on the travel path is generated from the digital road map representing the travel path of the mobile object. Further, the traveling of the moving body is controlled according to the traveling control information.

  Here, in order to accurately control the traveling of the moving body, a digital road map that accurately represents the shape of the traveling road is required. As a method for accurately representing the shape of the traveling road, a method of approximating the traveling road by smoothly approximating a plurality of measurement points on the traveling road with a B-Spline curve is known. .

  As a technique for approximating a traveling path with a B-spline curve in this way, there is a vehicle navigation device described in Patent Document 1.

  This vehicle navigation apparatus reads four measurement points continuous in the direction from the current position to the destination from the map data, and approximates the read measurement points with a B-spline curve. Then, the vehicle navigation device determines a road curve based on the curvature radius of the B-spline curve, and notifies information related to the curve based on the determination result. The vehicular navigation device supports the travel from the departure point to the destination by the moving body by repeating this process until the destination is reached.

Thereby, it becomes possible to control the traveling of the moving body with high accuracy, and it is possible to appropriately notify information about the curve.
JP 2000-321086 A

  In the vehicle navigation device described in Patent Document 1, the measurement points indicate two-dimensional coordinates. For this reason, the B-spline curve that approximates between the measurement points includes information on how to bend the traveling path such as the curvature of the traveling path, but the gradient of the traveling path, the gradient, and the rate of change along the traveling direction of the gradient. And information indicating the height of the road such as the bank inclination angle is not included. For this reason, there exists a problem that the precision which controls driving | running | working of a mobile body becomes low. This problem occurs not only when the measurement point is approximated by a B-spline curve but also when the measurement point is approximated by a general curve.

  In the vehicle navigation device described in Patent Document 1, local processing is performed when a traveling path is approximated using a B-spline curve. Specifically, the vehicular navigation device approximates the traveling path by repeating approximation by a B-spline curve of a measurement point near the current position to the destination. Accordingly, the traveling path is approximated by a plurality of B-spline curves, and the continuity of geometric information such as the tangent slope and curvature at both ends of each B-spline curve is not guaranteed. When such geometric information is approximated so as to be continuous, a region is generated in which each B-spline curve is distorted and does not represent a traveling path.

  An object of the present invention is to provide a traveling support apparatus and a traveling path curve generation method that solve the above-described problem that the accuracy of controlling traveling of a moving body is reduced.

  The driving support device according to the present invention includes an input unit that receives a plurality of measurement points indicated by position information in a three-dimensional space that is intermittently measured on a traveling path on which a moving body travels, and the input unit receives Generating means for approximating each measurement point with a smooth curve using position information indicating the measurement point, and generating a travel path curve representing the travel path.

  The traveling road curve generation method according to the present invention receives a plurality of measurement points indicated by position information in a three-dimensional space, intermittently measured on a traveling road on which a moving body travels, and the received measurement points are Using the position information shown, each measurement point is approximated by a smooth curve to generate a travel path curve representing the travel path.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to improve the precision which controls driving | running | working of a moving body.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a driving support system according to the first embodiment of the present invention. In FIG. 1, the driving support system includes an input device 1, a digital road map device 2, a control information generation device 3, a current position information grasping device 4, an output device 5, and a control device 6.

  In addition, the travel support system can be connected to a travel device 7 that travels the moving body. In the following, it is assumed that the moving body is an automobile. Further, traveling device 7 includes a steering 71, an accelerator 72, a brake 73, and a transmission 74.

The input device 1 receives travel information on the travel of the mobile body from the user of the mobile body. The travel information includes travel path specifying information for specifying a travel path on which the mobile body travels and travel conditions relating to travel of the mobile body. The traveling path specifying information indicates, for example, position information of the starting point and the destination of the moving body. The traveling condition indicates traveling that minimizes the time until the moving body reaches the destination, traveling that minimizes the CO ₂ emission amount, and the like.

  The input device 1 also receives a plurality of measurement points indicating position information measured on the traveling road, a plurality of road surface normal vectors at each measurement point, and a plurality of road surface tangent vectors at each measurement point.

  The measurement point is indicated by position information measured intermittently over at least the entire travel path on which the moving body travels from the departure place to the destination. Here, it is assumed that the position information is position information (x, y, z) in a three-dimensional space. The coordinate system of the position information can be selected so that, for example, the x direction represents latitude, y represents longitude, and the z direction represents altitude. However, the coordinate system of the position information is not limited to this representation and can be changed as appropriate.

  The road surface normal vector is a vector perpendicular to the traveling road surface at the measurement point. The road surface tangent vector is a vector that is in contact with the traveling road at the measurement point and faces the traveling direction of the moving body. It is assumed that the road surface normal vector and the road surface tangent vector are unit vectors.

  The measurement point, road surface normal vector, and road surface tangent vector are preferably measured on a center curve connecting the centers of the traveling roads. Furthermore, the interval at which the position information is measured is preferably an interval that ensures a necessary number for accurately calculating geometric information of the travel path described later.

  Note that the input device 1 receives, for example, measurement points from a measurement device (not shown) that measures them.

  The digital road map device 2 includes a road map generation unit 21, a B-spline basis function storage unit 22, a control point storage unit 23, and a knot vector storage unit 24.

  The road map generation unit 21 is an example of a generation unit. The road map generation unit 21 converts all the measurement points into one smooth 3 based on the position information indicating each measurement point received by the input device 1 and the road surface normal vector and the road surface tangent vector at each measurement point. A travel route curve representing the entire travel route is generated by approximating with a curve in the dimensional space.

  Below, the curve which approximates a measurement point is demonstrated as a B-spline (B-spline) curve. The curve approximating the measurement point is not limited to the B-spline and can be changed as appropriate.

  FIG. 2 is an explanatory diagram for explaining generation of a travel path curve. In FIG. 2, an approximate curve at the center of the lane of the road is shown as an example of the traveling road curve.

  For each measurement point, the road map generation unit 21 obtains a target normal vector N perpendicular to both the road surface normal vector n and the road surface tangent vector t at the measurement point. Note that the target normal vector is a unit vector. The target normal vector N is assumed to be directed in the direction of the center of curvature of the traveling road.

  The road map generation unit 21 approximates each measurement point with one p-order B-spline curve using a geometric processing method based on the measurement point and the target normal vector N, and generates a traveling road curve.

  Specifically, first, the road map generation unit 21 generates a B-spline curve having measurement points as control points.

  For example, the road map generation unit 21 selects a control point from the measurement points. Note that the number of control points is a number corresponding to a predetermined ratio of the number of measurement points. The predetermined ratio is, for example, 5%.

  Based on the selected control point, the road map generation unit 21 uses a straight distance method (chord length method) for obtaining a knot vector by a straight line distance between knots, or a centripetality for obtaining a knot vector by a square root of a straight line distance between knots. A knot vector is calculated using a centripetal method. The road map generation unit 21 obtains a B-spline basis function based on the calculated knot vector. Then, the road map generation unit 21 generates a linear combination of the B-spline basis function and the control point as a B-spline curve.

  Subsequently, for each control point, the road map generation unit 21 sets the control point by the vector connecting the control point and a contact point where the plane perpendicular to the target normal vector at the control point is in contact with the B-spline curve. By moving, the B-spline curve is transformed into a new B-spline. The road map generation unit 21 performs this process on a perpendicular line in which the distance between each measurement point and the new B-spline is less than a predetermined distance threshold value and is drawn from each measurement point to the new B-spline curve. Repeat until the angle between the curve normal vector at the foot and the target normal vector at each measurement point is less than a predetermined angle threshold. Note that the new B-spline curve is also of order p. Hereinafter, the distance between the measurement point and the B-spline curve is referred to as a distance error, and the angle between the target normal vector and the curve normal vector is referred to as an angle error.

  The road map generation unit 21 generates the approximate new B-spline curve as a travel road curve.

  Here, even if the geometric processing method is used (for example, the above processing is repeated a predetermined number of times), if the distance error does not become less than the distance threshold or the angle error does not become less than the angle threshold, the road The map generation unit 21 inserts knots at locations corresponding to measurement points where the distance error does not fall below the distance threshold or the angle error does not fall below the angle threshold. Then, the road map generation unit 21 performs the geometric processing method again on the B-spline curve in which the knot insertion has been performed. Note that the number of control points may change due to the knot insertion.

  If the traveling road curve obtained in this way is handled as a digital road map, the continuity of differentiation up to p-1 times is maintained at any point on the traveling road. Accordingly, it is possible to calculate the curvature, gradient, bank, and the like of the traveling path at an arbitrary point, and it is possible to calculate control information necessary for automatic operation for automatically controlling the traveling device of the moving body.

  Note that the same method can be used when the measurement point indicates positional information in a two-dimensional space.

  The storage unit including the B-spline basis function storage unit 22, the control point storage unit 23, and the knot vector storage unit 24 stores the traveling road curve generated by the road map generation unit 21.

  Specifically, the B-spline basis function storage unit 22 stores a B-spline basis function of a B-spline curve that is a traveling road curve. The control point storage unit 23 stores the control points of the B-spline curve. The knot vector storage unit 24 stores the knot vector of the B-spline curve.

  Note that a B-spline curve, which is a travel path curve, is represented by a linear combination of a plurality of control points and a B-spline basis function corresponding to each control point. Further, the B-spline basis function is obtained from a knot vector. Therefore, if the B-spline basis function, the control point, and the knot vector are stored, the traveling road curve is stored.

The control information generating device 3 receives control information for continuously controlling the traveling device 7 with respect to the position information based on the traveling road curve generated by the digital road map device 2. It is generated so as to satisfy the traveling condition accepted at.
At this time, the control information generating device 3 generates the control information so that the travel on the entire travel path specified by the travel path specifying information received by the input device 1 satisfies the travel condition.

  The control information includes, for example, steering control information for controlling the steering 71, accelerator control information for controlling the accelerator 72, brake control information for controlling the brake 73, and transmission control information for controlling the transmission 74.

  The control information generation device 3 includes a geometric information generation unit 31, a steering control information generation unit 32, an accelerator control information generation unit 33, a brake control information generation unit 34, and a transmission control information generation unit 35.

  The geometric information generation unit 31 acquires a travel path curve representing the travel path specified by the travel path specifying information from the storage unit. Specifically, the geometric information generation unit 31 acquires the B-spline basis function of the travel path curve from the B-spline basis function storage unit 22, and sets the control point of the travel path curve as the control point storage unit 23. And the knot vector of the traveling road curve is acquired from the knot vector storage unit 24.

  The geometric information generation unit 31 calculates geometric information of the travel path based on the acquired travel path curve. The geometric information includes, for example, the curvature of the road, the rate of change along the arc length of the curvature, the gradient, the rate of change along the direction of the gradient, and the bank inclination angle.

  For example, a B-spline curve that is a running road curve

  When the geometric information generating unit 31 represents the unit tangent vector of the B-spline curve,

  And calculate the unit normal vector of the B-spline curve.

  Ask for. Further, the geometric information generating unit 31 calculates the curvature of the B-spline curve as follows:

The rate of change along the length of the curvature,

Ask for. here,

It is. Further, the geometric information generating unit 31 uses the gradient as the rate of change along the arc length of the position in the z direction of the B-spline curve.

  Ask for. Furthermore, the geometric information generation unit 31 calculates the rate of change along the traveling direction of the gradient.

  Ask for. Furthermore, the z-direction unit vector

  And the angle formed by the z-axis and the unit normal vector of the B-spline curve is θ, the geometric information generation unit 31 determines the bank inclination angle.

  Ask for.

  The steering control information generating unit 32 generates steering control information based on the geometric information generated by the geometric information generating unit 31 so that the traveling of the moving body satisfies the traveling condition.

  The accelerator control information generation unit 33 generates accelerator control information based on the geometric information generated by the geometric information generation unit 31 so that the traveling of the moving body satisfies the traveling condition.

  The brake control information generation unit 34 generates brake control information based on the geometric information generated by the geometric information generation unit 31 so that the traveling of the moving body satisfies the traveling condition.

  The transmission control information generation unit 35 generates transmission control information based on the geometric information generated by the geometric information generation unit 31 so that the traveling of the moving body satisfies the traveling condition.

  The current position information grasping device 4 generates current position information that is current position information of the moving object. For example, the current position information grasping device 4 generates current position information with a GPS (Global Positioning System) function.

  The output device 5 outputs control information corresponding to the current position information generated by the current position information grasping device 4 among the control information generated by the control information generation device to the control device 6.

  The control device 6 controls the traveling device 7 based on the control information output from the output device 5 and the current position information.

  The control device 6 includes a steering control unit 61, an accelerator control unit 62, a brake control unit 63, and a transmission control unit 64.

  The steering control unit 61 controls the steering 71 of the traveling device 7 based on the steering control information and the current position information output from the output device 5.

  The accelerator control unit 62 controls the accelerator 72 of the traveling device 7 based on the accelerator control information and the current position information output from the output device 5.

  The brake control unit 63 controls the brake 73 of the traveling device 7 based on the brake control information and the current position information output from the output device 5.

  The transmission control unit 64 controls the transmission 74 of the traveling device 7 based on the transmission control information output from the output device 5 and the current position information.

  Next, the operation will be described.

  First, an operation when the travel support system generates a travel path curve will be described. FIG. 3 is a flowchart for explaining this operation. FIG. 4 is an explanatory diagram for explaining this process.

In step 301, when the input device 1 receives the measurement point Q _i , the road surface normal vector n _i and the road surface tangent vector t _i , the input device 1 converts the measurement point Q _i , road surface normal vector n _i and road surface tangent vector t _i into a digital road. It outputs to the road map production | generation part 21 of the map apparatus 2. FIG. It is assumed that i is 0 to s. s is the number of measurement points minus one.

When the road map generation unit 21 receives the measurement point, road surface normal vector, and road surface tangent vector, the B-spline curve C ⁽⁰⁾ having a plurality of measurement points Q _i (FIG. 4A) as control points P ⁽⁰⁾ _i. Is generated (FIG. 4B).

Specifically, first, the road map generation unit 21 selects a plurality of control points P ⁽⁰⁾ _i from a plurality of measurement points Q _i . In FIG. 4, the selected measurement point Q _i (control point P ⁽⁰⁾ _i ) is shown.

  Subsequently, the road map generation unit 21 calculates a knot vector. For example, the road map generation unit 21 calculates a knot vector using a linear distance method or a centripetal method in which an increment of the knot vector is obtained by a square root of the linear distance between the knots.

Further, the road map generation unit 21 obtains a B-spline basis function N _{i, p} (u) based on the knot vector. Here, i is 0 to s (s = number of control points−1), and p is the order of the B-spline curve. U is a parameter of the B-spline curve.

Then, the road map generation unit 21 generates a linear combination of the control point P ⁽⁰⁾ _i and the basis function N _{i, p} (u) as a B-spline curve C ⁽⁰⁾ .

When the road map generation unit 21 generates the B-spline curve C ⁽⁰⁾ , the road map generation unit 21 executes Step 302.

In step 302, the road map generation unit 21 draws a perpendicular line from each of the control points P ⁽⁰⁾ _i to the B spline curve C ⁽⁰⁾ , and points on the B spline curve C ^{(0) as} the foot of the perpendicular line. F ⁽¹⁾ _i is obtained (FIG. 4C). When the road map generation unit 21 obtains the point F ⁽¹⁾ _i , the road map generation unit 21 executes Step 303.

In step 303, the road map generation unit 21 obtains a target normal vector N _i perpendicular to both the road surface normal vector n _i and the road surface tangent vector t _i for each measurement point Q _i , and each target normal vector N It intersects _i perpendicular point having a tangent line G ⁽¹⁾ obtaining a _i (Figure 4D). When the road map generation unit 21 obtains the point G ⁽¹⁾ _i , it executes Step 304. In the case where a point having a tangent line intersecting the object normal vector N _i and vertically are a plurality, for example, road map generating unit 21, the point closest to the measurement point in that respect, the point G ⁽¹⁾ _Find as _i .

In step 304, the road map generation unit 21 performs the following processing for each control point P ⁽⁰⁾ _i .

First, the road map generation unit 21 obtains an angle error and a distance error of the control point P ⁽⁰⁾ _i . Angle error, and the normal vector of the B-spline curve C ⁽⁰⁾ at point F _i, the angle of the target normal vector N _i at the control point P ⁽⁰⁾ _i corresponding to the point F _i. The distance error is the distance from the control point P ⁽⁰⁾ _i to the B spline curve C ⁽⁰⁾ (point F _i ).

The road map generation unit 21 determines whether or not the angle error of the control point P ⁽⁰⁾ _i is equal to or greater than a predetermined angle threshold value. Furthermore, the road map generation unit 21 determines whether or not the distance error of the control point P ⁽⁰⁾ _i is equal to or greater than a predetermined distance threshold.

When the angle error is less than the angle threshold value and the distance error is greater than or equal to the distance threshold value, the road map generation unit 21 is the size of the vector from the point F ⁽¹⁾ _i to the control point P ⁽⁰⁾ _i. Then, the control point P ⁽⁰⁾ _i is moved in the direction of the vector to generate a new control point P ⁽¹⁾ _i (FIG. 4E).

If the angle error is equal to or greater than the angle threshold value and the distance error is less than the distance threshold value, the vector direction from the point G ⁽¹⁾ _i to the point F ⁽¹⁾ _i is increased in the direction of the vector. The control point P ⁽⁰⁾ _i is moved to generate a new control point P ⁽¹⁾ _i (FIG. 4F).

Furthermore, when the angle error is equal to or greater than the angle threshold value and the distance error is equal to or greater than the distance threshold value, the direction of the vector by the magnitude of the vector from the point G ⁽¹⁾ _i to the control point P ⁽⁰⁾ _i The control point P ⁽⁰⁾ _i is moved to to generate a new control point P ⁽¹⁾ _i (FIG. 4G).

When the road map generation unit 21 generates a new control point P ⁽¹⁾ _i for each control point P ⁽⁰⁾ _i , step S205 is executed. If the angle error is less than the angle threshold value and the distance error is less than the distance threshold value, the road map generation unit 21 does not move the control point P ⁽⁰⁾ _i and moves the control point P ^{(0 )} _i is a new control point P ⁽¹⁾ _i .

In step 305, the road map generation unit 21 generates a linear combination of the new control point P ⁽¹⁾ _i and the basis function N _{i, p} (u) as a new B-spline curve C ⁽¹⁾ (FIG. 4H).

  The road map generation unit 21 repeats Step 302 to Step 305 for all control points until the angle error is less than the angle threshold and the distance error is less than the distance threshold.

  The road map generation unit 21 executes Step 306 when the angle error is less than the angle threshold and the distance error is less than the distance threshold for each control point.

In step 306, the road map generation unit 21 generates a B-spline curve having the control point at that time. The road map generation unit 21 calculates the angle error and distance error of each measurement point Q _i for each measurement point Q _i .

The road map generation unit 21 determines, for each measurement point Q _i , whether the angle error at the measurement point Q _i is greater than or equal to the angle threshold, and whether the distance error at the measurement point Q _i is greater than or equal to the distance threshold.

  When there is at least one of a measurement point where the angle error is equal to or greater than the angle threshold and a measurement point where the distance error is equal to or greater than the distance threshold, the road map generation unit 21 inserts a knot (node insertion) at a location corresponding to the measurement point. : Knot insertion) to generate a new control point. Knot insertion is to insert a new knot into a knot vector defining the curve without changing the shape of the curve.

  The road map generation unit 21 repeats Step 302 to Step 306 until the angle error is less than the angle threshold and the distance error is less than the distance threshold for all measurement points.

  Next, the operation at the time of knot insertion will be described.

  Below, knot vector

  B-spline curve defined by

  And Also, insert the knot

  And the new knot vector is

  It becomes. The B-spline curve defined by this new knot vector has the same shape as C (t). That means

  It becomes.

At this time, a method of calculating a new control point R _i. Depending on the characteristics of the B-spline curve,

  Against

  And, moreover,

  It is. From Equations 17 and 18,

  It is.

For i from kp to k, the B-spline basis function N _{i, p} (t) is

  It is expressed. here,

  The

  Abbreviated. Substituting equation 20 into equation 17,

  Get. In Equation 23, if the knot vector before insertion is used instead of the new knot vector,

  It becomes. Where i is from k−p + 1 to k

  Then,

It becomes.

  Substituting Equation 25 and Equation 26 into Equation 24,

It becomes. By the above, all the control points Q _i are obtained from the equations 19 and 27.

  It becomes possible to ask for. In addition,

It is.

  Therefore, the road map generation unit 21 can obtain a new control point using Equation 28.

  Next, an operation for controlling the traveling of the moving body will be described. FIG. 5 is a flowchart for explaining this operation.

  In step 501, when the input device 1 receives travel information from the user of the moving body, the input device 1 outputs the travel information to the geometric information generation unit 31 of the control information generation device 3. When the geometric information generation unit 31 receives the travel information, the geometric information generation unit 31 executes Step 502.

  In step 502, the geometric information generation unit 31 acquires the basis function of the B-spline curve representing the travel route specified by the travel route specifying information in the travel information from the B-spline basis function storage unit 22, The control point of the B-spline curve is acquired from the control point storage unit 23, and the knot vector of the B-spline curve is acquired from the knot vector storage unit 24. The geometric information generation unit 31 reconstructs a B-spline curve, which is a traveling road curve, by linearly combining the basis functions and control points. The geometric information generation unit 31 executes Step 503 after completing Step 502.

  In step 503, the geometric information generation unit 31 generates geometric information of the traveling road based on the B-spline curve. The geometric information generating unit 31 converts the geometric information and the driving condition in the driving information into a steering control information generating unit 32, an accelerator control information generating unit 33, a brake control information generating unit 34, and a transmission control. It outputs to the information generation part 35. Thereafter, step 504 is executed.

  In step 504, upon receiving the geometric information, the steering control information generation unit 32 generates steering control information based on the geometric information so that the traveling of the moving body satisfies the traveling condition. The steering control information generation unit 32 outputs the generated steering control information to the output device 5.

  When receiving the geometric information, the accelerator control information generating unit 33 generates the accelerator control information based on the geometric information so that the traveling of the moving body satisfies the traveling condition. The accelerator control information generation unit 33 outputs the generated accelerator control information to the output device 5.

  When receiving the geometric information, the brake control information generation unit 34 generates the brake control information based on the geometric information so that the traveling of the moving body satisfies the traveling condition. The brake control information generation unit 34 outputs the generated brake control information to the output device 5.

  When receiving the geometric information, the transmission control information generating unit 35 generates transmission control information based on the geometric information so that the traveling of the moving body satisfies the traveling condition. The transmission control information generation unit 35 outputs the generated transmission control information to the output device 5.

  When the output device 5 receives the steering control information, the accelerator control information, the brake control information, and the transmission control information, the output device 5 executes Step 505.

  In step 505, the output device 5 receives current position information from the current position information grasping device 4. Note that the current position information grasping device 4 always measures the current position information and outputs the current position information.

  The output device 5 extracts steering control information, accelerator control information, brake control information, and transmission control information corresponding to the current position information from each of the steering control information, accelerator control information, brake control information, and transmission control information. The output device 5 outputs the extracted steering control information to the steering control unit 61, outputs the extracted accelerator control information to the accelerator control unit 62, and outputs the extracted brake control information to the brake control unit 63. The extracted transmission control information is output to the transmission control unit 64. Thereafter, the control device 6 executes Step 506.

  In step 506, when the steering control unit 61 receives the steering control information, the steering control unit 61 controls the steering 71 according to the steering control information.

  When receiving the accelerator control information, the accelerator control unit 62 controls the accelerator 72 according to the accelerator control information.

  When receiving the brake control information, the brake control unit 63 controls the brake 73 according to the brake control information.

  When receiving the transmission control information, the transmission control unit 64 controls the transmission 74 according to the transmission control information.

  Next, the effect will be described.

  In the present embodiment, the input device 1 receives a plurality of measurement points indicated by position information in a three-dimensional space, which are intermittently measured on a traveling path on which the moving body travels. The road map generation unit 21 uses the position information indicating the measurement points received by the input device 1 to approximate each measurement point with a curve in a smooth three-dimensional space, and generates a travel route curve representing the travel route. .

  In this case, since the traveling road is approximated by a curve in a three-dimensional space, not only information on how to bend the traveling road, such as the curvature of the traveling road, but also the gradient, the rate of change along the traveling direction of the gradient, and the bank inclination It is also possible to generate information that represents the height of the travel path such as a corner. Therefore, it is possible to represent the travel path more accurately, and it is possible to improve the accuracy of controlling the travel of the moving body.

  Moreover, in this embodiment, the road map generation part 21 calculates | requires the object normal vector N perpendicular | vertical to both the road surface normal vector n and the road surface tangent vector t in the measurement point about each measurement point. Further, the road map generation unit 21 generates a B-spline curve having measurement points as control points. Subsequently, for each control point, the road map generation unit 21 sets the control point by a vector connecting the control point and a contact point where a plane perpendicular to the target normal vector at the control point is in contact with the B-spline curve. By moving, the B-spline curve is transformed into a new B-spline. The road map generation unit 21 performs this process on a perpendicular line in which the distance between each measurement point and the new B-spline is less than a predetermined distance threshold value, and the new B-spline curve is drawn from each measurement point. Repeat until the angle between the curve normal vector at the foot and the target normal vector at each measurement point is less than a predetermined angle threshold.

  In this case, the distance between the new B-spline curve serving as the travel path curve and the measurement point can be reduced, so that the travel path curve can be generated with high accuracy. Furthermore, the angle between the target normal vector at the measurement point and the curve normal vector of the travel path curve at the measurement point can be reduced, so that the twist of the travel path curve can be suppressed. Therefore, it is possible to improve the accuracy of the geometric information of the travel path. Therefore, it is possible to generate a travel path curve with high accuracy.

  Further, the input device 1 accepts a plurality of measurement points indicating each of the position information measured intermittently over the entire travel path on which the moving body travels from the departure place to the destination. The road map generation unit 21 approximates between all the measurement points received by the input device 1 with one smooth curve, and generates a travel route curve representing the entire travel route.

  In this case, a plurality of measurement points indicating each of the position information measured over the entire travel path are interpolated with one smooth curve. Therefore, it is possible to guarantee the continuity of geometric information at an arbitrary position on the curve representing the traveling road while suppressing the distortion of the traveling road curve.

  Moreover, in this embodiment, the input device 1 receives the travel conditions regarding the travel of the moving body. The control information generation device 3 provides control information for controlling the traveling device 7 that the mobile body travels based on the travel route curve generated by the road map generation unit 21 so that the travel of the mobile body satisfies the travel conditions. To generate.

  In this case, continuity such as tangent and curvature is ensured at an arbitrary location on the travel path curve, so that it is possible to generate control information capable of controlling the travel device 7 with high accuracy.

  In the present embodiment, the control device 6 controls the traveling device 7 according to the control information generated by the control information generating device 3.

  In this case, continuity such as tangent and curvature is ensured at an arbitrary location on the travel path curve, so that the travel device 7 can be controlled with high accuracy.

  Next, a second embodiment will be described.

  FIG. 6 is a block diagram showing the travel route support system of the present embodiment. In FIG. 6, the driving support system includes a display device 8 in addition to the configuration shown in FIG. In FIG. 6, components having the same functions as those in FIG.

  The display device 8 is, for example, car navigation. The display device 8 displays the traveling road curve generated by the digital road map device 2 and the current position information measured by the current position information grasping device 4. As a result, a more accurate road shape can be displayed, and the user of the travel route support system can grasp the travel route.

  In each embodiment described above, the illustrated configuration is merely an example, and the present invention is not limited to the configuration.

  For example, although the mobile body has been described as an automobile, the mobile body is not limited to an automobile and can be changed as appropriate. For example, the moving body may be a fixed track moving body that moves on a predetermined track such as a railroad.

  Further, a more general NURBS (Non-Uniform Rational B-Spline) curve including a B-spline curve may be used instead of the B-spline curve. The B-spline curve is a case where the weight of the NURBS curve is 1.

It is the block diagram which showed the driving assistance system of 1st embodiment of this invention. It is explanatory drawing for demonstrating the production | generation of a travel path curve. It is a flowchart for demonstrating operation | movement at the time of a driving assistance system producing | generating a driving path curve. It is explanatory drawing for demonstrating the operation | movement at the time of a driving assistance system producing | generating a road curve. It is explanatory drawing for demonstrating the operation | movement at the time of a driving assistance system producing | generating a road curve. It is explanatory drawing for demonstrating the operation | movement at the time of a driving assistance system producing | generating a road curve. It is explanatory drawing for demonstrating the operation | movement at the time of a driving assistance system producing | generating a road curve. It is explanatory drawing for demonstrating the operation | movement at the time of a driving assistance system producing | generating a road curve. It is explanatory drawing for demonstrating the operation | movement at the time of a driving assistance system producing | generating a road curve. It is explanatory drawing for demonstrating the operation | movement at the time of a driving assistance system producing | generating a road curve. It is explanatory drawing for demonstrating the operation | movement at the time of a driving assistance system producing | generating a road curve. It is a flowchart for demonstrating the operation | movement at the time of controlling driving | running | working of a moving body. It is the block diagram which showed the driving assistance system of 2nd embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input device 2 Digital road map apparatus 3 Control information generation apparatus 4 Current position information grasping apparatus 5 Output apparatus 6 Control apparatus 7 Traveling apparatus 8 Display apparatus 21 Road map generation part 22 B-Spline basis function storage part 23 Control point storage part 24 Knot vector storage unit 31 Geometric information generation unit 32 Steering control information generation unit 33 Accelerator control information generation unit 34 Brake control information generation unit 35 Transmission control information generation unit 61 Steering control unit 62 Acceleration control unit 63 Brake control unit 64 Transmission control Part 71 Steering 72 Accelerator 73 Brake 74 Transmission

Claims (10)

Input means for receiving a plurality of measurement points indicated by position information in a three-dimensional space, intermittently measured on a travel path on which the mobile body travels;
Generating means for approximating each measurement point with a curve in a smooth three-dimensional space using position information indicating the measurement point received by the input means, and generating a travel path curve representing the travel path; Driving support system. The driving support system according to claim 1,
The input means includes a plurality of road surface normal vectors perpendicular to the traveling road at each measurement point, and a plurality of road surface tangent vectors that are in contact with the traveling road at each measurement point and face the traveling direction of the moving body. Further acceptance,
The generating means generates a NURBS curve having each measurement point as a control point, and obtains a target normal vector perpendicular to both the road surface normal vector and the road surface tangent vector at the measurement point for each measurement point, Further, for each control point, the NURBS curve is renewed by moving the control point by a vector connecting the control point and a plane perpendicular to the target normal vector at the control point and a contact point in contact with the NURBS curve. The process of transforming into a NURBS curve is performed by a curve normal at the foot of a perpendicular line where the distance between each measurement point and the new NURBS curve is less than a predetermined distance threshold value, and descends from each measurement point to the new NURBS curve. The driving support system repeats until the angle between the vector and the target normal vector at each measurement point is less than a predetermined angle threshold. Beam. In the driving support system according to claim 1 or 2,
Each measurement point is indicated by each position information measured intermittently over the entire travel path on which the mobile body travels from the starting point to the destination.
The generation means includes: approximating all measurement points with one smooth curve, and generating a curve representing the entire travel path as the travel path curve. In the driving support system according to any one of claims 1 to 3,
The input means receives a traveling condition related to traveling of the moving body,
Control information for controlling a travel device that travels the mobile body based on the travel path curve generated by the generation means so that the travel of the mobile body satisfies the travel conditions received by the input means. A driving support system including control information generating means for generating. In the driving support system according to claim 4,
A travel support system including travel control means for controlling the travel device according to control information generated by the control information generation means. Accepts a plurality of measurement points indicated by position information on a three-dimensional space, intermittently measured on a travel path on which the mobile object travels,
A travel support method for generating a travel route curve representing the travel route by approximating each measurement point with a curve in a smooth three-dimensional space using the received position information indicating the measurement point. The driving support method according to claim 6,
Further accepting a plurality of road surface normal vectors perpendicular to the traveling road at each measurement point, and a plurality of road surface tangent vectors in contact with the traveling road at each measurement point and facing the traveling direction of the moving body,
A NURBS curve having each measurement point as a control point is generated, and for each measurement point, a target normal vector perpendicular to both the road surface normal vector and the road surface tangent vector at the measurement point is obtained, and each measurement point , A process of moving the control point by a vector connecting the measurement point with a point that is perpendicular to the target normal vector at the measurement point and the measurement point, and transforming the NURBS curve into a new NURBS curve. , The distance between each measurement point and the new NURBS curve is less than a predetermined distance threshold, and the curve normal vector at the foot of the perpendicular line from each measurement point to the new NURBS curve and the object at each measurement point A driving support method that repeats until the angle with the normal vector is less than a predetermined angle threshold. In the driving support method according to claim 6 or 7,
Each measurement point is indicated by each position information measured intermittently over the entire travel path on which the mobile body travels from the starting point to the destination.
A driving support method comprising: approximating all of each measurement point with one smooth curve, and generating a curve representing the entire driving road as the driving road curve. In the traveling road curve generation method according to any one of claims 6 to 8,
Accepting the travel conditions relating to the travel of the mobile body;
A travel path curve that generates control information for controlling a travel device that travels the moving body based on the generated travel path curve so that the travel of the mobile body satisfies the accepted travel condition. Generation method. In the traveling road curve generation method according to claim 9,
A traveling road curve generation method for controlling the traveling device according to the generated control information.

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