JP2018008623A - Vehicular control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular control device which can reduce a radial physical constitution of a steering shaft.SOLUTION: A steering wheel 10 has a circular rim 10a which is a grip part gripped by an operator, and hub 10b which is provided at a center position of the rim 10a and is fitted coaxially with the steering shaft 11. A GPS sensor 30 is fitted at a position coaxially with the steering shaft 11 in the hub 10b. A GPS sensor 31 is fitted to the rim 10a. An ECU 4 captures a reference absolute coordinate Co which is detected through the GPS sensor 30, and a floating absolute coordinate Cp which is detected through the GPS sensor 31. The ECU 4 calculates a steering angle θ of the steering wheel 10 based on the reference absolute coordinate Co and the floating absolute coordinate Cp.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle control device.

  Conventionally, there is a steering device that detects a steering angle of a steering wheel by an angle sensor provided on a steering shaft. Such a steering device assists the driver's steering operation based on the steering angle detected through the angle sensor (Patent Document 1).

Japanese Patent Laying-Open No. 2015-71356

  By the way, when an angle sensor is provided on the steering shaft, the physique in the radial direction of the steering shaft becomes large. For this reason, the physique of a steering device will become large and the mountability (freedom of layout) at the time of arranging a steering device in vehicles will fall.

  The objective of this invention is providing the control apparatus for vehicles which can make the physique of the radial direction of a steering shaft small.

  The vehicle control device that can achieve the above object is provided at a position away from the rotation center of the reference position information detected by the first position detection sensor provided in the host vehicle and the steering wheel of the vehicle. In the vehicle control device that captures the floating position information detected by the second position detection sensor, a relative position of the floating position information to the reference position information based on a difference between the reference position information and the floating position information. A relative position information calculation unit that calculates information; and a steering angle calculation processing unit that calculates a steering angle of the steering wheel based on the relative position information.

  According to this configuration, the steering angle calculation processing unit can calculate the steering angle of the steering wheel based on the relative position information calculated from the reference position information and the floating position information in the relative position information calculation unit. For this reason, if the vehicle is provided with the first and second position detection sensors, there is no need to provide an angle sensor for detecting the steering angle on the steering shaft. For this reason, the physique of the radial direction of a steering shaft can be made small.

  In the above vehicle control device, the steering wheel includes a hub that is attached to be integrally rotatable with a steering shaft as a rotation center, and a circular rim that is connected to the hub and is gripped by a driver. It is preferable that the second position detection sensor is attached to the rim, and the first position detection sensor is attached coaxially with the rotation center of the steering wheel.

  According to this configuration, the first position detection sensor does not move even when the steering wheel rotates by attaching the first position detection sensor coaxially with the rotation center of the steering wheel. In addition, by attaching the second position detection sensor to the rim, the second position detection sensor can be attached to a portion that is usually farthest from the center of rotation in the steering wheel. For this reason, when the steering wheel rotates, the amount of displacement of the second position detection sensor in the circumferential direction increases, so that the detection accuracy of the second position information is improved. Thereby, the calculation accuracy of the steering angle calculated by the steering angle calculation processing unit is improved.

  In the above vehicle control device, the steering wheel includes a hub that is attached to be integrally rotatable with a steering shaft as a rotation center, and a circular rim that is connected to the hub and is gripped by a driver. It is preferable that the second position detection sensor is attached to the rim, and the first position detection sensor is fixed to a vehicle body.

  According to this configuration, since the first position detection sensor is fixed to the vehicle body, the first position detection sensor does not move even when the steering wheel rotates. Further, when the steering wheel rotates, the amount of displacement in the circumferential direction of the second position detection sensor increases, so that the detection accuracy of the second position information is improved. Thereby, the calculation accuracy of the steering angle calculated by the steering angle calculation processing unit is improved.

  In the above vehicle control device, the reference position information and the floating position information are absolute coordinates of a world coordinate system, and the relative position information calculation unit subtracts the reference position information from the floating position information. The position vector to the floating position information related to the reference position information is calculated as the relative position information, and the steering angle calculation processing unit calculates a steering angle of the steering wheel based on the position vector. preferable.

  According to this configuration, the relative position information calculation unit can calculate a position vector based on the reference position information and the floating position information. Then, the steering angle calculation processing unit can calculate the steering angle based on this position vector.

In the above vehicle control device, it is preferable that the first position detection sensor and the second position detection sensor are GPS sensors.
According to this configuration, the GPS sensor provided as the first position detection sensor detects the reference absolute coordinates as the reference position information, and the GPS sensor provided as the second position detection sensor uses the floating absolute coordinates as the floating position information. Is detected.

  According to the vehicle control device of the present invention, the size of the steering shaft in the radial direction can be reduced.

The block diagram which shows schematic structure which mounted the vehicle control apparatus of 1st Embodiment in the vehicle. The block diagram which shows schematic structure of the sensor attached to a steering wheel connected with the vehicle control apparatus in the vehicle control apparatus of 1st Embodiment. The block diagram which shows schematic structure of the control apparatus for vehicles of 1st Embodiment. The figure which shows the method to detect the steering angle of the steering wheel in the vehicle control apparatus of 1st Embodiment based on the two absolute coordinates obtained from two GPS sensors while the vehicle is stopped. The figure which shows the method of detecting the steering angle of the steering wheel during the movement of a vehicle based on the two absolute coordinates obtained from two GPS sensors in the vehicle control apparatus of 2nd Embodiment. (A), (b) is a figure which shows the method of detecting the steering angle of a steering wheel based on the two absolute coordinates obtained from two GPS sensors in the control apparatus for vehicles of 3rd Embodiment. The figure which shows the method of detecting the steering angle of a steering wheel based on the two absolute coordinates obtained from two GPS sensors in the vehicle control apparatus of 4th and 5th embodiment. The figure which shows the method of detecting the steering angle of a steering wheel based on the two absolute coordinates obtained from two GPS sensors in the vehicle control apparatus of other embodiment.

<First Embodiment>
Hereinafter, a first embodiment of a vehicle control device will be described.
As shown in FIG. 1, the vehicle 1 includes a steering device 2, two pairs of front and rear wheels 3, and an ECU 4 (electronic control device) as a vehicle control device.

  The steering device 2 includes a steering wheel 10, a steering shaft 11, a rack shaft 12, a rack and pinion mechanism 13, and a tie rod 14. The steering wheel 10 is fixed to the steering shaft 11 so as to be integrally rotatable. The rack and pinion mechanism 13 is configured by engaging pinion teeth provided at the lower end portion of the steering shaft 11 with rack teeth provided on a rack shaft 12 that is a steered shaft. The rotational motion of the steering shaft 11 is converted into a reciprocating linear motion in the axial direction of the rack shaft 12 via the rack and pinion mechanism 13. Tie rods 14 are connected to both ends of the rack shaft 12. The rack and pinion mechanism 13 converts the rotation of the steering shaft 11 into the reciprocating linear motion of the rack shaft 12, thereby changing the turning angle of the wheel 3 (the steered wheel therein).

  A motor 20 is provided in the vicinity of the rack shaft 12. The rotational force of the motor 20 is converted into the axial force of the rack shaft 12 via the transmission mechanism 21, thereby assisting the driver's steering operation.

  The steering wheel 10 is provided with two GPS sensors 30 and 31 (global positioning system sensors) as position detection sensors. The GPS sensors 30 and 31 receive information (time signal and orbit information) transmitted from GPS satellites, and calculate the absolute coordinates of their current position based on the information. The absolute coordinate is an absolute position in the world coordinate system (global coordinate system).

  The ECU 4 controls the driving of the motor 20 based on vehicle state quantities detected through various sensors including the GPS sensors 30 and 31. As various sensors, for example, a vehicle speed sensor and a torque sensor (not shown) are employed.

Next, the two GPS sensors 30 and 31 attached to the steering wheel 10 will be described in detail.
As shown in FIG. 2, the steering wheel 10 includes a circular rim 10 a that is a grip portion gripped by the driver, and a hub 10 b that is provided at the center of the rim 10 a and is coaxially mounted on the steering shaft 11. have. The rim 10a and the hub 10b are connected. The rim 10a, the hub 10b, and the steering shaft 11 rotate integrally.

  A GPS sensor 30 is attached at a position coaxial with the steering shaft 11 in the hub 10b. For this reason, even when the steering wheel 10 rotates, the GPS sensor 30 is located on the same axis (rotation center) as the steering shaft 11 and does not move with respect to the steering shaft 11. As an example, the GPS sensor 30 is embedded in the hub 10b.

  A GPS sensor 31 is attached to the rim 10a. As an example, the GPS sensor 31 is embedded in the upper part of the rim 10a when the steering wheel 10 is in the neutral position. That is, the GPS sensor 31 is provided at a position away from the center of rotation in the steering wheel 10. When the steering wheel 10 rotates, the GPS sensor 31 rotates together with the rim 10a with the steering shaft 11 as the rotation center. In addition, since the displacement amount of the GPS sensor 31 increases as the distance from the rotation center of the steering wheel 10 increases, the detection accuracy of the calculated steering angle θ is improved. For this reason, the GPS sensor 31 is preferably provided on the rim 10a.

  Since the GPS sensor 30 is always located at the center of rotation when the steering wheel 10 rotates, it is used as a reference when detecting the steering angle θ of the steering wheel 10. In contrast, the GPS sensor 31 rotates around the GPS sensor 30 as the steering wheel 10 rotates. For this reason, the ECU 4 can detect the steering angle θ of the steering wheel 10 by using the output information of the GPS sensor 30 and the output information of the GPS sensor 31. Here, in order to simplify the description, it is assumed that the vehicle 1 is in a stopped state.

  The GPS sensor 30 generates reference absolute coordinates Co that are its own absolute coordinates based on information from GPS satellites. Further, the GPS sensor 31 generates floating absolute coordinates Cp that are its own absolute coordinates based on information from GPS satellites. The GPS sensor 30 and the GPS sensor 31 generate the reference absolute coordinate Co and the floating absolute coordinate Cp for every fixed control cycle.

  The ECU 4 includes a steering angle calculation unit 40 and a control unit 50. The steering angle calculation unit 40 steers the steering wheel 10 based on the reference absolute coordinates Co (reference position information) detected through the GPS sensor 30 and the floating absolute coordinates Cp (floating position information) detected through the GPS sensor 31. The angle θ is calculated. The control unit 50 calculates a motor control signal that is a signal for controlling the motor 20 based on the steering angle θ calculated by the steering angle calculation unit 40.

Next, the configuration of the steering angle calculation unit 40 will be described in detail.
As shown in FIG. 3, the steering angle calculation unit 40 of the ECU 4 includes a relative coordinate calculation unit 41, a steering angle calculation processing unit 42, and a steering direction determination unit 43.

  The relative coordinate calculation unit 41 calculates a relative coordinate Cr of the floating absolute coordinate Cp with respect to the reference absolute coordinate Co by calculating a difference between the floating absolute coordinate Cp and the reference absolute coordinate Co. Here, the relative coordinate Cr is a position vector to the floating absolute coordinate Cp that is an arbitrary point related to the reference absolute coordinate Co that is a reference point. That is, the relative coordinate Cr represents the coordinate of the floating absolute coordinate Cp with the reference absolute coordinate Co as the origin. The relative coordinate calculation unit 41 calculates a relative coordinate Cr (reference position vector) with respect to the reference absolute coordinate Co of the absolute coordinate serving as a reference for the steering angle θ. The reference position vector is a position vector to the absolute coordinate of the zero point of the steering angle θ with respect to the reference absolute coordinate Co that is a reference point when the steering wheel 10 is in the neutral position. The steering angle θ is an angle formed by the current reference position vector and the current position vector. The reference position vector does not move even when the steering wheel 10 rotates.

  The steering angle calculation processing unit 42 is based on the current position vector (relative coordinate Cr) calculated by the relative coordinate calculation unit 41 and the current reference position vector (relative coordinate Cr) calculated by the relative coordinate calculation unit 41. Thus, the steering angle θ of the steering wheel 10 is calculated by calculating the inner product thereof.

  The steering direction determination unit 43 is based on the current position vector (relative coordinate Cr) calculated by the relative coordinate calculation unit 41 and the current reference position vector (relative coordinate Cr) calculated by the relative coordinate calculation unit 41. The steering direction of the steering wheel 10 is determined by calculating their outer product.

Next, a calculation method of the position vector (relative coordinate Cr) calculated by the relative coordinate calculation unit 41 will be described. First, various preconditions will be described with reference to FIG.
As shown in FIG. 4, the circular track C is a track on the outer peripheral edge of the steering wheel 10. A point O is located at the center of the circular orbit C, and points P0 and P1 are located on the circular orbit C. Since the steering wheel 10 may be inclined by a certain angle with respect to the absolute coordinate system (for example, its XY plane), the circular orbit C is illustrated in an elliptical shape here. The point O (x0, y0, z0) is the reference absolute coordinate Co. Note that the parenthesis indicates a vector component in three-dimensional coordinates when the point O is expressed in a three-dimensional (xyz) coordinate system. Point P0 is a coordinate when the steering wheel 10 is located at the neutral position, and is an absolute coordinate serving as a reference for the steering angle θ. The coordinates of the point P0 are the point P0 (xp0, yp0, zp0). The point P0 is determined based on the reference absolute coordinate Co currently measured by the GPS sensor 30. The relative relationship between the coordinates of the point O and the coordinates of the point P0 is determined in advance. As the absolute coordinate of the point O changes, the absolute coordinate of the point P0 also changes in the same manner, so that the floating absolute coordinate Cp from the point O that is the reference absolute coordinate Co calculated by the relative coordinate calculation unit 41. The relative coordinates Cr (position vector) toward the point P0 are constant. The coordinates of the point P1 are the point P1 (xp1, yp1, zp1). The point P1 is the floating absolute coordinate Cp currently measured by the GPS sensor 31. The steering angle θ of the steering wheel 10 is an angle formed by the point P0, the point O, and the point P1 that is the floating absolute coordinate Cp. Here, since it is assumed that the vehicle 1 is stopped, the reference absolute coordinate Co (point O) does not move. However, even when the vehicle 1 is traveling, the point P0 changes corresponding to the movement of the reference absolute coordinate Co, so the reference position vector is constant, and the floating absolute coordinate Cp also corresponds to the movement of the reference absolute coordinate Co. Since the point P1 changes, the position vector is the same as that when the vehicle 1 is stopped.

  The relative coordinate calculation unit 41 (see FIG. 3) calculates a position vector vOP0 to the point P0 regarding the point O. Specifically, the relative coordinate calculation unit 41 calculates the position vector vOP0 using the following equation (1). Here, instead of the arrow indicating the vector, a subscript “v” is described at the beginning of the character string indicating the vector.

vOP0 = P0-O
= (Xp0, yp0, zp0)-(x0, y0, z0)
= (Xp0-x0, yp0-y0, zp0-z0) (1)
That is, the position vector vOP0 is obtained by subtracting the absolute coordinate of the point O from the absolute coordinate of the point P0. Note that, since the component at the point P0 includes the component at the point O, the position vector vOP0 is constant. The position vector vOP0 is a reference position vector.

Further, the relative coordinate calculation unit 41 calculates the position vector vOP1 to the point P1 related to the point O using the following equation (2).
vOP1 = P1-O
= (Xp1, yp1, zp1)-(x0, y0, z0)
= (Xp1-x0, yp1-y0, zp1-z0) (2)
Next, the steering angle calculation processing unit 42 (see FIG. 3) calculates the steering angle θ of the steering wheel 10 using the position vectors vOP0 and vOP1. Here, the inner product of the position vector vOP0 and the position vector vOP1 is expressed by the following equation (3). Here, “·” means an inner product, and “*” means multiplication. “||” means the size of the vector.

vOP0 · vOP1 = | vOP0 | * | vOP1 | * cos θ (3)
When equation (3) is solved for θ, the following equation (4) is obtained. “Arccos” represents an arc cosine (inverse cosine) function, that is, an inverse function of the cosine function.

θ = arccos {vOP0 · vOP1 / | vOP0 | * | vOP1 |} (4)
The steering angle calculation processing unit 42 calculates the steering angle θ of the steering wheel 10 using Expression (4). Note that the calculated steering angle θ means an angle between the position vector vOP0 and the position vector vOP1. Unless the steering wheel 10 is assembled to the steering shaft 11 in an unstable manner, the circular orbit C drawn when the steering wheel 10 is rotated is constant. Therefore, the position between the position vector vOP0 and the position vector vOP1 is constant. The angle matches the steering angle θ.

  The steering direction determination unit 43 (see FIG. 3) determines the rotation direction of the steering wheel 10 using the position vectors vOP0 and vOP1. This is because, even when the steering angle θ is calculated using the inner product of the position vector vOP0 and the position vector vOP1, it is not known in which direction the steering wheel 10 has rotated. Here, the outer product of the position vector vOP0 and the position vector vOP1 is expressed by the following equation (5). Here, “x” means an outer product.

vOP0 × vOP1 = (xp0−x0, yp0−y0, zp0−z0)
× (xp1-x0, yp1-y0, zp1-z0) (5)
That is, the steering wheel 10 is rotated in the direction of the right-hand thread as viewed from the normal vector in the plane formed by the position vector vOP0 and the position vector vOP1. Thereby, the steering direction (right steering or left steering) of the steering wheel 10 can be determined. Specifically, the normal vector (vOP0 × vOP1) in the direction seen from the plane of the circular orbit C is positive, and the normal vector in the opposite direction is negative. The steering direction determination unit 43 determines the steering direction of the steering wheel 10 based on whether the calculation result of “vOP0 × vOP1” is positive or negative.

The operation and effect of this embodiment will be described.
The steering angle calculator 40 can detect the steering angle θ of the steering wheel 10 based on the reference absolute coordinate Co and the floating absolute coordinate Cp obtained through the GPS sensors 30 and 31 attached to the steering wheel 10. That is, the steering angle calculation unit 40 calculates the relative coordinate Cr by calculating the difference between the reference absolute coordinate Co and the floating absolute coordinate Cp, and is calculated by the reference position vector serving as the reference of the steering angle θ and the movement of the GPS sensor 31. The steering angle θ can be calculated by calculating the inner product with the position vector.

  Since the ECU 4 can detect the steering angle θ by the GPS sensors 30 and 31 attached to the steering wheel 10, it is not necessary to provide an angle sensor for detecting the steering angle θ on the steering shaft 11. For this reason, the physique of the radial direction of the steering shaft 11 can be made small. The size of the steering device 2 can also be reduced. As the physique of the steering device 2 becomes smaller, the mountability when the steering device is mounted on the vehicle is improved (the degree of freedom in layout is increased).

  Incidentally, according to the related art, since the steering shaft 11 is provided with the angle sensor for detecting the steering angle θ, the physique in the radial direction of the steering shaft 11 and the physique of the steering device 2 are increased. As the angle sensor, for example, there is a sensor having a magnet attached to the outer peripheral surface of the steering shaft 11 and a magnetic sensor arranged via a gap with the magnet. The magnetic sensor generates an electrical signal corresponding to a change in the magnetic field accompanying the rotation of the steering shaft 11. The ECU 4 detects the steering angle θ based on this electrical signal.

Second Embodiment
Next, a second embodiment of the vehicle control device will be described. Here, the difference from the first embodiment will be mainly described. In the second embodiment, it is assumed that the vehicle 1 is traveling such that the reference absolute coordinate Co (point O) moves.

  As shown in FIG. 5, as the vehicle 1 moves, the steering wheel 10 also moves in the same direction, so that the circular orbit C of the steering wheel 10 changes from the circular orbit C1 to the circular orbit as time t elapses. Move to C2. At this time, the vehicle 1 is moving at the speed V. For this reason, the vehicle 1 moves by the distance Vt during the time t. That is, the initial reference absolute coordinate Co is the point O and the floating absolute coordinate Cp is the point P0. However, the reference absolute value after the elapse of time t is obtained when the vehicle 1 moves at the speed V during the time t. The coordinate Co moves to the point Ot, and the floating absolute coordinate Cp moves to the point P1t.

Here, when the velocity V is decomposed into three-dimensional components, the velocity V can be expressed as a vector by the following equation (6).
V = (Vx, Vy, Vz) (6)
For this reason, the distance Vt that the vehicle 1 has moved during the time t can be expressed by the following equation (7).

Vt = V · t
= T · (Vx, Vy, Vz)
= (Vx · t, Vy · t, Vz · t) (7)
The reference absolute coordinate Co moves from the point O (x0, y0, z0) to the point Ot (x0 + Vx · t, y0 + Vy · t, z0 + Vz · t) as the vehicle 1 moves by the distance Vt as time t passes. ing.

  Further, the floating absolute coordinate Cp is also moved by the distance Vt as the time t elapses. The point P0 (xp0, yp0, zp0), which is the initial floating absolute coordinate Cp, has moved to the point P0t (xp0 + Vx · t, yp0 + Vy · t, zp0 + Vz · t). Actually, since the GPS sensor 31 (floating absolute coordinate Cp) moves from the point P0 to the point P0t as the steering wheel 10 rotates, the point P0t does not actually exist, but the explanation is easy. It is illustrated to make it. Actually, the GPS sensor 31 (floating absolute coordinate Cp) is moved to the point P1t (xp1 + Vx · t, yp1 + Vy · t, zp1 + Vz · t) because the vehicle 1 has moved by the distance Vt.

  The relative coordinate calculation unit 41 calculates a position vector as in the first embodiment. The initial position vector vOP0 is calculated by Expression (1) as in the first embodiment. On the other hand, the reference absolute coordinate Co and the floating absolute coordinate Cp are moved by the movement of the vehicle 1 and the rotation of the steering wheel 10 with the passage of time t. However, if the reference absolute coordinate Co and the floating absolute coordinate Cp are the same, the position vector vOtP1t can be expressed by the following equation (8).

vOtP1t = P1t-Ot
= (Xp1 + Vx · t, yp1 + Vy · t, zp1 + Vz · t)
− (X0 + Vx · t, y0 + Vy · t, z0 + Vz · t)
= (Xp1-x0, yp1-y0, zp1-z0) (8)
That is, the relative coordinate calculation unit 41 can calculate the position vector vOtP1t by the equation (8). Note that the calculation result of the position vector vOtP1t calculated by Expression (8) is the same as the calculation result of the position vector vOP1 calculated by Expression (2).

  Hereinafter, in the steering angle calculation processing unit 42, the calculation by the equation (4) using the position vector vOtP1t instead of the position vector vOP1, the steering angle θ can be calculated. Further, in the steering direction determination unit 43, the steering direction can be determined by performing the calculation according to the equation (5) using the position vector vOtP1t instead of the position vector vOP1.

The operation and effect of this embodiment will be described.
Even when the vehicle 1 is moving, if the three-dimensional component of the speed V can be detected, the steering angle θ can be calculated by the steering angle calculator 40 as in the first embodiment. That is, as in the first embodiment, the steering angle θ and the steering direction can be determined by calculating the inner product and outer product of the position vector vOP0 and the position vector vOtP1t.

<Third Embodiment>
Next, a third embodiment of the vehicle control device will be described. Here, the difference from the first embodiment will be mainly described.

  As shown in FIG. 6A, the absolute coordinates of the point O that is the reference absolute coordinate Co and the points P0 and P1 that are the floating absolute coordinate Cp are the same as those in the first embodiment. Since the absolute coordinates of the points O, P0, and P1 detected through the GPS sensors 30 and 31 are three-dimensional coordinate displays in the world coordinate system, the steering wheel 10 may be tilted with respect to the world coordinate system. . Here, it is assumed that the plane on which the steering wheel 10 rotates (formed by the circular orbit C) is inclined about the x axis by an angle β. For example, an angle β is formed between the position vector vOP0 and the z axis. In the present embodiment, the calculation is simplified by converting the absolute coordinates of the points O, P0, and P1 into two-dimensional coordinates on the plane on which the steering wheel 10 rotates. As an example, the y ′ axis is set so as to be along the position vector vOP0 serving as a reference for the steering angle θ. Then, on the plane on which the steering wheel 10 rotates, the x ′ axis is set to be orthogonal to the y ′ axis.

  As shown in FIG. 6B, points O ′, P0 ′, and P1 ′ on the plane on which the steering wheel 10 rotates (hereinafter referred to as x′y ′ plane) are the world coordinates of the points O, P0, and P1. The three-dimensional absolute coordinates of the system are converted into the two-dimensional absolute coordinates of the x′y ′ coordinate system.

That is, the points O ′, P0 ′, P1 ′ and the points O, P0, P1 are expressed by the following equations (9) to (11) using the coordinate transformation matrix [A]. “·” Means inner product.
O ′ = [A] · O (9)
P0 ′ = [A] · P0 (10)
P1 ′ = [A] · P1 (11)
Note that the coordinate transformation matrix [A] depends on the tilt angle β of the steering wheel 10 and the direction of the vehicle 1, and therefore changes in real time as the vehicle 1 moves. Therefore, in the x′y ′ coordinate system, the point O can be expressed as a point O ′ (x0 ′, y0 ′). Similarly, in the x′y ′ coordinate system, the point P0 can be expressed as a point P0 ′ (xp0 ′, yp0 ′), and the point P1 can be expressed as a point P1 ′ (xp1 ′, yp1 ′).

  By the way, the point P 0 ′, which is a neutral location point, can be uniquely determined with respect to the point O. When detecting the steering angle θ, for example, the point P0 ′, which is a neutral point, must be obtained in advance, or the initial steering wheel 10 must be set to the neutral position. Here, since the y ′ axis is set along the position vector vOP0 serving as a reference for the steering angle θ, if the magnitude of the position vector vO′P0 ′ is known, that is, the rotation of the rim 10a of the steering wheel 10 If the radius (for example, | vO′P0 ′ |) is known, the size of the position vector vO′P0 ′ may be added to the y ′ component of the point O ′. In this case, the point P0 'can be expressed as a point P0' (x0 ', y0' + | vO'P0 '|).

  Regarding the rotation of the steering wheel 10 from the point P0 'to the point P1', the steering angle θ can be obtained by performing the same calculation as the equations (1) to (5) of the first embodiment. That is, the relative coordinate calculation unit 41 calculates points O ′, P0 ′, P1 ′, and calculates a position vector using these points O ′, P0 ′, P1 ′. For example, the relative coordinate calculation unit 41 calculates the position vector vO′P0 ′ and the position vector vO′P1 ′ using the following expressions (12) and (13).

vO′P0 ′ = (xp0′−x0 ′, yp0′−y0 ′) (12)
vO′P1 ′ = (xp1′−x0 ′, yp1′−y0 ′) (13)
Therefore, the steering angle calculation processing unit 42 can calculate the steering angle θ by the following expression (14) with reference to the expression (4).

θ = arccos {vO′P0 ′ · vO′P1 ′ / | vO′P0 ′ | * | vO′P1 ′ |}
= Arccos {(xp0'-x0 '). (Xp1'-x0') + (yp0'-y0 '). (Yp1'-y0')} / rt {(xp0'-x0 ') ^ 2+ (yp0' −y0 ′) ^ 2} / rt {(xp1′−x0 ′) ^ 2+ (yp1′−y0 ′) ^ 2} (14)
“Rt” means the root, that is, the square root.

Further, the steering direction determination unit 43 can determine the steering direction by the following equation (15) with reference to the equation (5).
vO'P0 'x vO'P1'
= (Xp0'-x0 ', yp0'-y0')
× (xp1′−x0 ′, yp1′−y0 ′)
= (Xp0'-x0 '). (Yp1'-y0')-(yp0'-y0 '). (Xp1'-x0') (15)
The steering direction determination unit 43 determines the steering direction of the steering wheel 10 based on whether the calculation result of Expression (15) is positive or negative.

The operation and effect of this embodiment will be described.
By converting the points O, P0, P1, which are absolute coordinates in the three-dimensional coordinate system of the world coordinate system, to the points O ', P0', P1 ', which are two-dimensional absolute coordinates in the x'y' coordinate system Since the calculation of the inner product and the outer product is simplified, the calculation load of the steering angle calculation processing unit 42 and the steering direction determination unit 43 can be reduced.

  That is, conventionally, in the calculation of the steering angle calculation processing unit 42 and the steering direction determination unit 43, the position vectors vOP0 and vOP1 have a three-dimensional component (x, y, z). It was necessary to calculate the inner product and outer product of the components. In this regard, according to the present embodiment, the position vectors vO′P0 ′ and vO′P1 ′ have two-dimensional components (x ′, y ′), so that inner products and outer products of the two-dimensional components are calculated. Therefore, the calculation is relatively easy.

<Fourth embodiment>
Next, a fourth embodiment of the vehicle control device will be described. Here, the difference from the first embodiment will be mainly described.

  As shown by a two-dot chain line in FIG. 1, in this embodiment, the GPS sensor 30a is fixed to the center position (vehicle body) in the vehicle 1 instead of the GPS sensor 30 attached to the hub 10b. The position of the GPS sensor 30a relative to the steering shaft 11 does not change even when the steering wheel 10 is rotated. That is, in this embodiment, the absolute coordinate generated by the GPS sensor 30a is adopted as the reference absolute coordinate Co. Here, it is assumed that the vehicle 1 of the vehicle 1 is in a stopped state as in the first embodiment.

  As shown in FIG. 7, the reference absolute coordinate Co obtained by the GPS sensor 30a is a point O (x0, y0, z0) regardless of time. On the other hand, the floating absolute coordinate Cp obtained by the GPS sensor 31 moves from the point P0s (xp0s, yp0s, zp0s) to the point P1s (xp1s, yp1s, zp1s) as the steering wheel 10 rotates. That is, the floating absolute coordinate Cp moves on the circular orbit C of the steering wheel 10.

  Incidentally, the three-dimensional coordinate system of the points O, P0s, and P1s detected through the GPS sensors 30a and 31 may be inclined with respect to the circular orbit C of the steering wheel 10. For example, in the present embodiment, it is assumed that the plane formed by the circular orbit C is inclined about the x axis by an angle β, as in the third embodiment.

  Here, in the first to third embodiments, since the GPS sensor 30 is attached to the hub 10b, the estimation and calculation of the circular orbit C of the steering wheel 10 by the GPS sensor 30 and the GPS sensor 31 are compared. It was easy. In this respect, in the present embodiment, only one GPS sensor 31 is positioned on the plane formed by the circular orbit C. Therefore, the two GPS sensors 30 and 31 are positioned on the plane formed by the circular orbit C. It is more difficult to estimate the circular orbit C than when it is.

  However, even in this embodiment, if it is known in advance that the GPS sensor 31 passes on a certain circular orbit as the steering wheel 10 rotates, a plurality of floating absolute coordinates Cp of the GPS sensor 31 are detected. Thus, the circular orbit C can be estimated. At this time, it is also possible to estimate the inclination angle β between the circular orbit C and the three-dimensional coordinate system of the points O, P0s and P1s. Then, using this angle β and the vehicle direction, the three-dimensional absolute coordinates of the world coordinate system of the points O, P0, and P1 are converted into x using the coordinate transformation matrix [A] as in the third embodiment. It can be converted to two-dimensional absolute coordinates in the 'y' coordinate system. The steering angle θ and the steering direction can be calculated by using the points O, P0, and P1 converted into the two-dimensional absolute coordinates of the x′y ′ coordinate system.

The operation and effect of this embodiment will be described.
Even when the GPS sensor 30 a is attached to the vehicle 1, the circular orbit C can be estimated by detecting a plurality of floating absolute coordinates Cp detected through the GPS sensor 31. Then, if the inclination angle β between the circular orbit C and the three-dimensional coordinate system of the points O, P0s and P1s is estimated, the points O, P0s and P1s are converted into two-dimensional absolute coordinates of the x′y ′ coordinate system. can do. Therefore, the steering angle θ and the steering direction can be calculated.

<Fifth Embodiment>
Next, a fifth embodiment of the vehicle control device will be described. Here, the difference from the fourth embodiment will be mainly described.

  In this embodiment, it is assumed that the relative coordinates of the point Os (x0s, y0s, z0s), which is the center of rotation of the circular orbit C, with respect to the point O (x0, y0, z0) are known in advance. That is, the position vector vOOs regarding the point O to the point Os is known. For example, when the steering device 2 is assembled to the vehicle 1, the relative coordinate calculation unit 41 stores the position vector vOOs by measuring the relationship between the GPS sensor 30a and the point O. The position vector vOOs is expressed by the following equation (16).

vOOs = Os-O
= (X0s, y0s, z0s)-(x0, y0, z0)
= (X0s-x0, y0s-y0, z0s-z0) (16)
The relative coordinate calculation unit 41 calculates a position vector vOP0s to the point P0s regarding the point O as the relative coordinate Cr. Specifically, the position vector vOP0s is calculated using the following equation (17) (see FIG. 3).

vOP0s = P0s-O
= (Xp0s, yp0s, zp0s)-(x0, y0, z0)
= (Xp0s-x0, yp0s-y0, zp0s-z0) (17)
Further, the relative coordinate calculation unit 41 calculates the position vector vOP1s of the point P1s related to the point O using the following equation (18).

vOP1s = P1s-O
= (Xp1s, yp1s, zp1s)-(x0, y0, z0)
= (Xp1s-x0, yp1s-y0, zp1s-z0) (18)
Further, the relative coordinate calculation unit 41 in the present embodiment converts the position vectors vOP0s and vOP1s of the points P0s and P1s related to the point O into position vectors related to the point Os. The position vector vOsP0s can be represented by a vector difference between the position vector vOP0s and the position vector vOOs. That is, the relative coordinate calculation unit 41 calculates the position vector vOsP0s using the following equation (19).

vOsP0s = vOP0s-vOOs
= (Xp0s-x0, yp0s-y0, zp0s-z0)
-(X0s-x0, y0s-y0, z0s-z0)
= (Xp0s-x0s, yp0s-y0s, zp0s-z0s) (19)
The position vector vOsP1s can be represented by a vector difference between the position vector vOP1s and the position vector vOOs. The relative coordinate calculation unit 41 calculates the position vector vOsP1s using the following equation (20).

vOsP1s = vOP1s-vOOs
= (Xp1s-x0s, yp1s-y0s, zp1s-z0s) (20)
Next, the steering angle calculation processing unit 42 calculates the steering angle θ of the steering wheel 10 by the following equation (21) using the position vectors vOsP0s and vOsP1s.

θ = arccos {vOsP0s · vOsP1s / | vOsP0s | * | vOsP1s |} (21)
The steering direction determination unit 43 calculates the steering angle θ of the steering wheel 10 according to the following equation (22) using the position vectors vOsP0s and vOsP1s.

vOsP0s × vOsP1s = (xp0s−x0, yp0s−y0, zp0s−z0) × (xp1s−x0, yp1s−y0, zp1s−z0) (22)
The steering direction determination unit 43 determines the steering direction of the steering wheel 10 based on whether the calculation result of “vOsP0s × vOsP1s” is positive or negative.

The operation and effect of this embodiment will be described.
If the position of the point Os with respect to the point O is known, even if the GPS sensor 30a is attached to the vehicle 1, it is based on the reference absolute coordinate Co and the floating absolute coordinate Cp obtained through the GPS sensors 30a and 31. The steering angle calculation unit 40 can detect the steering angle θ of the steering wheel 10.

  In this case, in the first to third embodiments, the GPS sensor 30 is provided in the hub 10 b of the steering wheel 10, but the GPS sensor 30 a may be provided somewhere in the vehicle 1. For this reason, it is only necessary to attach the GPS sensor 31 to the rim 10a of the steering wheel 10. For example, it is suitable when the GPS sensor 30 cannot be provided in the hub 10b, such as when some function is provided in the hub 10b.

Each embodiment may be changed as follows. The following other embodiments can be combined with each other within a technically consistent range.
In each embodiment, various position vectors are calculated as relative coordinates Cr by the relative coordinate calculation unit 41, but the present invention is not limited to this. For example, the relative coordinate calculation unit 41 uses the reference absolute coordinate Co detected through the GPS sensor 30 (GPS sensor 30a), the floating absolute coordinate Cp detected through the GPS sensor 31, and the reference absolute coordinate Co as the origin. You may convert into a display. In order to convert the floating absolute coordinate Cp into a display using the reference absolute coordinate Co as the origin, the reference absolute coordinate Co may be subtracted from the floating absolute coordinate Cp.

  In FIG. 8, a two-dimensional coordinate system is displayed for ease of explanation and calculation. Points P0 ', P1', and P2 'are obtained by converting the floating absolute coordinate Cp into a display with the reference absolute coordinate Co as the origin. Further, the distance from the point O to the points P0 ', P1', P2 ', that is, the radius of the steering wheel 10 is set to "1". The coordinate of the point P0 'is set as a reference point with a steering angle θ of "0". At this time, when the floating absolute coordinate Cp is at the point P1 '(0, 1), the steering angle calculation processing unit 42 calculates the steering angle θ1' as 90 degrees by simple calculation of a trigonometric function. Further, when the floating absolute coordinate Cp is at the point P2 ′ (rt (2) / 2, rt (2) / 2), the steering angle calculation processing unit 42 calculates the steering angle θ1 ′ by a simple calculation of a trigonometric function. It can be calculated as 45 degrees.

  In each embodiment, the steering angle θ is calculated from the change in the position of the floating absolute coordinate Cp. However, the reference point (and the position vector) is determined in advance, and the change in the position of the floating absolute coordinate Cp from that point is determined. The steering angle θ may be calculated based on the above.

  -In each embodiment, although the GPS sensor 31 was attached to the rim | limb 10a, it is not restricted to this. For example, the GPS sensor 31 may be provided at a position shifted from the center of rotation in the hub 10b. That is, the GPS sensor 31 may be provided at any position as long as the GPS sensor 31 is provided at a position away from the rotation center as the steering wheel 10 rotates.

  -In each embodiment, although the point P0 and the point P0s were uniquely determined with respect to the point O and the point Os, it is not restricted to this. For example, the position information calculated in the past than the current position information (the floating absolute coordinates Cp calculated before a certain calculation cycle before the calculation of the points P1 and P1s) is included in the points P0 and P0s. May be used. That is, the steering angle calculation unit 40 may calculate the steering angle θ using not only the current position information but also past position information.

  In the first to third embodiments, the GPS sensor 30 is attached to the center position of the hub 10b. However, the GPS sensor 30 may be shifted from the center position of the hub 10b by an allowable range as long as correction is possible.

  In each embodiment, the GPS sensors 30, 30a, and 31 are employed as position detection sensors, but the present invention is not limited to this. For example, a sensor that detects the position using an optical device such as a laser may be employed.

  The ECU 4 may be embodied as a steer-by-wire (SBW) control device without being limited to the electric power steering device that assists the linear motion of the rack shaft 12 in conjunction with the steering operation using the rotational force of the motor 20. Further, the ECU 4 can be embodied not only as a control device for a front wheel steering device but also as a control device for a rear wheel steering device or a four-wheel steering device (4WS).

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Steering device, 3 ... Wheel, 4 ... ECU (vehicle control device), 10 ... Steering wheel, 10a ... Rim, 10b ... Hub, 11 ... Steering shaft, 12 ... Rack shaft, 13 ... Rack and Pinion mechanism, 14 ... tie rod, 20 ... motor, 21 ... transmission mechanism, 30, 30a, 31 ... GPS sensor (position detection sensor), 40 ... steering angle calculation unit, 41 ... relative coordinate calculation unit, 42 ... steering angle calculation process , 43 ... Steering direction determination part, 50 ... Control part, β ... Angle, θ ... Steering angle, C, C1, C2 ... Circular trajectory, t ... Time, V ... Speed, Co ... Reference absolute coordinate (reference position information) , Cp: floating absolute coordinates (floating position information), Cr: relative coordinates, vOOs, vOP0, vOP1, vOP0s, vOP1s, vOsP0s, vOsP1s, vOtP1t ... Kuttle.

Claims (5)

Reference position information detected by a first position detection sensor provided in the host vehicle and a floating position detected by a second position detection sensor provided at a position away from the center of rotation of the steering wheel of the vehicle. In a vehicle control device that captures information,
A relative position information calculation unit that calculates relative position information of the floating position information with respect to the reference position information based on a difference between the reference position information and the floating position information;
A vehicle control apparatus comprising: a steering angle calculation processing unit that calculates a steering angle of the steering wheel based on the relative position information. The vehicle control device according to claim 1,
The steering wheel has a hub attached to be rotatable integrally with a steering shaft as a rotation center, and a circular rim connected to the hub and gripped by a driver,
The second position detection sensor is attached to the rim,
The first position detection sensor is a vehicle control device that is mounted coaxially with a rotation center of the steering wheel. The vehicle control device according to claim 1,
The steering wheel has a hub attached to be rotatable integrally with a steering shaft as a rotation center, and a circular rim connected to the hub and gripped by a driver,
The second position detection sensor is attached to the rim,
The first position detection sensor is a vehicle control device fixed to a vehicle body. The vehicle control device according to any one of claims 1 to 3,
The reference position information and the floating position information are absolute coordinates of the world coordinate system,
The relative position information calculation unit calculates a position vector to the floating position information related to the reference position information as the relative position information by subtracting the reference position information from the floating position information,
The steering angle calculation processing unit is a vehicle control device that calculates a steering angle of the steering wheel based on the position vector. In the vehicle control device according to any one of claims 1 to 4,
The first position detection sensor and the second position detection sensor are vehicle control devices that are GPS sensors.