JP2017001415A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control device which hardly imparts incongruity to a driver.SOLUTION: In a vehicle control device (1) which is used in a vehicle having steering units (35, 135) which perform steering, and a steering wheel (41) which rotates in conjunction with the steering, the vehicle control device comprises: a steering control unit (7) which performs steering by using the steering units; and a limit unit (7) which limits the rotation of the steering wheel accompanied by the steering in a first case that the steering control unit performs the steering compared with a second case that the steering control unit performs the steering resulting from a steering operation of a driver.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle control device.

  In recent vehicles, an electric power steering system that detects steering of a driver and assists the steering force with a motor according to the steering torque is generally used. In recent years, vehicles equipped with a function of automatically steering regardless of the driver's intention have been mass-produced, and this function is often realized by electric power steering.

  In addition, a technique has been proposed in which when an obstacle is detected in front of the host vehicle, the vehicle shifts to an avoidance travel mode in which the turning ability is improved more than usual (see Patent Document 1).

JP 2002-274344 A

  A vehicle control device that automatically steers when an obstacle is detected in front of the host vehicle may be considered. When the vehicle control device automatically performs steering, the steering shaft is connected to the steering shaft, so that the steering rotates in conjunction with the steering shaft. In this case, the driver's hand holding the steering wheel is moved against the intention, which may cause discomfort to the driver. The present invention has been made in view of these problems, and an object of the present invention is to provide a vehicle control device that is less likely to cause discomfort to the driver.

  A vehicle control device according to the present invention is a vehicle control device used in a vehicle including a steering unit that performs steering and a steering that rotates in conjunction with the steering, the steering control unit performing steering using the steering unit, and a driver Compared to the second case in which steering is performed due to steering of the steering wheel, the first case in which the steering control unit performs steering includes a limiting unit that restricts rotation of the steering accompanying steering. To do.

  According to the vehicle control device of the present invention, in the first case, the rotation of the steering accompanying the steering can be limited. As a result, the driver's discomfort associated with the driver's hand holding the steering wheel being moved unintentionally can be reduced.

1 is a block diagram illustrating a configuration of a vehicle control device 1. FIG. 4 is an explanatory diagram illustrating a configuration of a steering unit 35. FIG. It is a flowchart showing the process which the vehicle control apparatus 1 performs. 4 is a graph showing a relationship between a steering amount and a rotation amount of a steering 41. 4 is a graph showing the relationship between the elapsed time and the amount of rotation of a steering 41 when increasing the steering amount at a constant speed. 4 is an explanatory diagram illustrating a configuration of a steering unit 135. FIG. 1 is a block diagram illustrating a configuration of a vehicle control device 1. FIG.

Embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
1. Configuration of Vehicle Control Device 1 The configuration of the vehicle control device 1 will be described with reference to FIGS. The vehicle control device 1 is an in-vehicle device mounted on a vehicle. Hereinafter, the vehicle on which the vehicle control device 1 is mounted is referred to as the own vehicle. The vehicle control device 1 is a known computer including a CPU, RAM, ROM, and the like. The vehicle control device 1 executes processing to be described later with a program stored in the ROM.

As shown in FIG. 1, the vehicle control device 1 functionally includes an obstacle recognition unit 3, an avoidance travel control unit 5, and a vehicle motion control unit 7. The function of each unit will be described later.
In addition to the vehicle control device 1, the host vehicle includes a camera 9, a millimeter wave radar 11, a laser radar 13, a sonar 15, a locator 17, a four-wheel wheel speed sensor 19, a steering angle sensor 21, a front and rear G sensor 23, and a left and right G sensor. 25, a yaw rate sensor 27, a torque sensor 29, a driving force control unit 31, a brake control unit 33, and a steering unit 35.

  The camera 9 captures the surroundings of the host vehicle and creates image data. The millimeter wave radar 11, the laser radar 13, and the sonar 15 all detect obstacles (for example, other vehicles, pedestrians, fixed objects, etc.) existing around the host vehicle. The locator 17 includes a GPS and acquires position data of the host vehicle. The four-wheel wheel speed sensor 19 detects the wheel speed of the host vehicle. The steering angle sensor 21 detects an angle (rotation amount from a reference position) in the steering of the host vehicle.

  The front-rear G sensor 23 detects acceleration in the front-rear direction of the host vehicle. The left / right G sensor 25 detects acceleration in the left / right direction (vehicle width direction) of the host vehicle. The yaw rate sensor 27 detects the yaw rate of the host vehicle. The torque sensor 29 detects the rotational torque of the steering. The rotational torque detected by the torque sensor 29 is generated when the driver of the host vehicle performs normal steering and rotates the steering. The driving force control unit 31 controls the driving force of the host vehicle. The brake control unit 33 controls the brake operation of the host vehicle. The steering unit 35 steers the host vehicle.

  Next, the steering unit 35 will be further described with reference to FIGS. The steering unit 35 has a known mechanical configuration such as a steering 41, a steering shaft 43, a rack and pinion 45, a tie rod 47, and the like. The steering 41 is rotatably held.

  Basically, when the steering 41 rotates, the steering shaft 43 also rotates in conjunction with it. When the steering shaft 43 rotates, the tie rod 47 connected to the steering shaft 43 is moved in the left-right direction in FIG. 2 by the rack and pinion 45, whereby the direction of the wheels 49 is changed and steering is performed. Therefore, steering can be performed by the driver grasping the steering 41 and rotating it (by performing steering steering). Hereinafter, the amount of change in the direction of the wheel 49 at the time of steering (the magnitude of the turning angle) will be referred to as a steering amount.

  Further, the steering unit 35 includes a motor 37 and a VGR (variable gear ratio) motor 39. The motor 37 applies rotational torque to the steering shaft 43. The direction of the rotational torque applied by the motor 37 is the same as the direction of assisting steering (that is, the rotational direction of the steering 41 when steering is performed due to the rotation of the steering 41 (due to the steering of the driver)). Direction).

  Further, when performing steering avoidance described later, the direction of the rotational torque applied by the motor 37 is a direction in which the host vehicle steers in the direction in which the vehicle should travel in order to avoid contact with an obstacle. Therefore, when performing steering avoidance, steering is automatically performed by the rotational torque applied by the motor 37 even if the driver does not rotate the steering 41.

  The VGR motor 39 is provided at a position where the steering shaft 43 is divided into two. Of the steering shaft 43, a portion above the VGR motor 39 is an upper shaft 43A, and a portion below the VGR motor 39 is a lower shaft 43B. The VGR motor 39 has a function of changing the rotation amount of the upper shaft 43A when the lower shaft 43B rotates by a unit amount.

  Here, the rotation amount of the lower shaft 43B is proportional to the steering amount of the steering unit 35, and the rotation amount of the upper shaft 43A is proportional to the rotation amount of the steering 41. Therefore, the VGR motor 39 has a function of changing the rotation amount of the steering 41 per unit steering amount.

The vehicle motion control unit 7 is an example of a steering control unit and a limiting unit. The avoidance travel control unit 5 is an example of a determination unit.
2. Processing Performed by Vehicle Control Device 1 Processing that the vehicle control device 1 repeatedly executes at predetermined time intervals will be described with reference to FIGS. In step 1 of FIG. 3, the obstacle recognition unit 3 acquires the image data of the camera 9, the detection result of the millimeter wave radar 11, the detection result of the laser radar 13, and the detection result of the sonar 15. Then, the obstacle recognition unit 3 determines whether or not the obstacle has been recognized based on them. If the obstacle can be recognized, the process proceeds to step 2. If the obstacle cannot be recognized, the process ends.

  In step 2, the obstacle recognition unit 3 calculates the trajectory of the obstacle determined to have been recognized in step 1 (hereinafter referred to as an obstacle trajectory). The obstacle trajectory is a predicted trajectory of the obstacle in the future. The obstacle trajectory is calculated as follows. The data of the same obstacle as the obstacle recognized in the immediately preceding step 1 is retrieved retroactively, and the position is read out. The vehicle control device 1 stores obstacle data recognized in the past.

  Next, the positions of the obstacles are arranged in the order of the passage of time, and the past trajectories of the obstacles are calculated by connecting them. Then, assuming that the obstacle moves in the same direction at the same speed in the future, the obstacle trajectory is calculated by extrapolating to the past trajectory.

  In step 3, the obstacle recognition unit 3 calculates a predicted trajectory in the future of the host vehicle (hereinafter referred to as the host vehicle track). The calculation method is the same as the calculation method of the obstacle trajectory. Next, the host vehicle trajectory calculated in this way and the obstacle trajectory calculated in step 2 are compared to determine whether the obstacle collides with the host vehicle.

  In other words, if the own vehicle track and the obstacle track intersect and the timing at which the host vehicle reaches the intersection and the timing at which the obstacle arrives are the same, the obstacle collides with the host vehicle. Otherwise, it is determined that the two do not collide. If it is determined that the obstacle collides with the host vehicle, the process proceeds to step 4. If it is determined that the obstacle does not collide, the process ends.

  In step 4, the avoidance travel control unit 5 determines whether or not the driver is grasping the steering 41. Specifically, if the value of the torque detected by the torque sensor 29 is equal to or greater than the threshold value, it is determined that the driver is holding the steering 41, and otherwise, it is determined that the driver is not holding the steering 41. If it is determined that the driver is not grasping the steering 41, the process proceeds to step 5, and if it is determined that the driver is grasping the steering 41, the process proceeds to step 6.

  In step 5, first, the avoidance travel control unit 5 determines the content of steering avoidance. Steering avoidance is a process of automatically steering and adjusting the vehicle speed to avoid collision with an obstacle. The contents of steering avoidance are the steering direction, the steering amount, and the target vehicle speed.

  In order to determine the content of steering avoidance, the avoidance travel control unit 5 acquires signals from the locator 17, the four-wheel wheel speed sensor 19, the steering angle sensor 21, the front / rear G sensor 23, the left / right G sensor 25, and the yaw rate sensor 27. Recognize the situation of the vehicle (position, speed, acceleration, steering angle, yaw rate, etc.). Then, the avoidance travel control unit 5 determines the content of steering avoidance by combining the situation of the host vehicle and the obstacle track calculated in Step 2.

  Next, the vehicle motion control unit 7 executes the steering avoidance determined as described above. That is, steering is performed using the steering unit 35, and the vehicle speed is adjusted to the target vehicle speed using the driving force control unit 31 and the brake control unit 33. The steering here is automatic steering by the rotation of the motor 37.

  In Step 5, when steering is avoided, the rotation of the steering 41 is not limited. That is, the relationship between the steering amount when steering is avoided and the rotation amount, rotation speed, etc. of the steering 41 is the relationship when the driver rotates the steering 41 (due to steering by the driver) and steers. It is the same.

  On the other hand, if an affirmative determination is made in step 4, the process proceeds to step 6. In Step 6, the avoidance travel control unit 5 and the vehicle motion control unit 7 perform steering avoidance basically in the same manner as in Step 5.

  However, in this step 6, the vehicle motion control unit 7 limits the rotation of the steering 41 accompanying the steering when the steering avoidance is executed. The mode of restriction can be any of the following (i) to (iv). The limitation on the rotation of the steering 41 can be realized by changing the rotation amount of the upper shaft 43A when the lower shaft 43B rotates by a unit amount in the VGR motor 39.

  (i) Even if steering is performed, the steering 41 is not rotated. The relationship between the steering amount and the rotation amount of the steering 41 in this case is shown by the curve L1 in FIG. In the curve of L1, even if the steering amount increases, the rotation amount of the steering 41 remains zero.

  FIG. 4 is a graph showing the relationship between the steering amount and the rotation amount of the steering 41. L2 is a curve representing the relationship between the steering amount and the rotation amount of the steering 41 when the driver performs steering by gripping the steering 41 and rotating it.

  (ii) An upper limit is set for the rotational speed of the steering 41. The behavior of the steering 41 in this case is shown in FIG. FIG. 5 shows the relationship between the elapsed time and the rotation amount of the steering 41 when the steering amount is increased at a constant speed. When the upper limit X is provided for the rotation speed of the steering 41, the rotation amount of the steering 41 increases only at a slow speed equal to or lower than the upper limit X as shown by a curve L3 in FIG. The slope of the curve L3 in FIG. 5 (the amount of change in the steering rotation amount with respect to the unit amount of elapsed time) is X or less.

  The curve L4 is a curve when the driver performs steering by gripping the steering 41 and rotating it. In this case, since the upper limit is not provided for the rotational speed of the steering 41 (or an upper limit greater than the upper limit X is provided), the amount of rotation of the steering 41 can be rapidly increased compared to the curve L3. .

  (iii) An upper limit is set for the rotation amount of the steering 41. The behavior of the steering 41 in this case is indicated by a curve L5 in FIG. In the curve of L5, while the steering amount is small, the rotation amount of the steering 41 increases as the steering amount increases, but when the rotation amount of the steering 41 reaches the upper limit Y, even if the steering amount further increases, The steering 41 does not rotate any further.

  (iv) The amount of rotation of the steering 41 per unit steering amount is reduced. The behavior of the steering 41 in this case is indicated by a curve L6 in FIG. The curve of L6 has a smaller amount of rotation of the steering 41 per unit steering amount than the curve of L2.

3. Effects of vehicle control device 1 (1A) When the vehicle motion control unit 7 performs steering as part of steering avoidance (first case), the vehicle control device 1 performs steering due to the steering of the driver. Compared to the case (second case), the rotation of the steering 41 accompanying the steering is limited. As a result, the driver's discomfort associated with the driver's hand holding the steering wheel 41 being moved against his / her intention can be reduced.

(1B) The vehicle control device 1 uses any one of (i) to (iv) as a mode for restricting the rotation of the steering 41. As a result, driver discomfort can be reduced.
(1C) The vehicle control device 1 determines whether or not the driver is grasping the steering 41, and restricts the rotation of the steering 41 on the condition that it is determined that the driver is grasping the steering 41. As a result, when the necessity is low, it is possible to prevent the process of limiting the rotation of the steering 41 from being executed.

(1D) The vehicle control device 1 performs steering avoidance when an obstacle is recognized. Steering avoidance may be executed at an unexpected timing by the driver. Even in such a case, the vehicle control device 1 restricts the rotation of the steering 41 so that the driver's hand holding the steering 41 is intended. The driver's discomfort associated with being moved against the driver can be reduced.
<Second Embodiment>
Since the basic configuration of the second embodiment is the same as that of the first embodiment, the description of the common configuration will be omitted, and differences will be mainly described.

1. Difference from First Embodiment The vehicle control device 1 includes a steering unit 135 shown in FIGS. 6 and 7. The steering unit 135 is of a type called a steer-by-wire system. The steering unit 135 has a known mechanical configuration such as a steering 41, a steering shaft 43, a rack and pinion 45, a tie rod 47, and the like. The steering 41 is rotatably held.

  The steering shaft 43 is divided into an upper shaft 43A and a lower shaft 43B, and a clutch 51 is provided between them. The clutch 51 normally separates the upper shaft 43A and the lower shaft 43B. When the upper shaft 43A and the lower shaft 43B are separated, even if one of the upper shaft 43A and the lower shaft 43B is rotationally driven, the driving force is not transmitted to the other. The clutch 51 connects the upper shaft 43A and the lower shaft 43B only in an emergency.

  Further, the steering unit 135 includes a motor 37. The motor 37 is controlled by the vehicle motion control unit 7. The motor 37 applies rotational torque to the lower shaft 43B. The steering unit 135 is steered by the rotational torque applied by the motor 37.

  Steering by the driver rotating the steering wheel 41 is performed as follows. When the driver rotates the steering 41, the torque sensor 29 detects the rotation direction and the rotation amount. The motor 37 applies steering torque to the lower shaft 43B according to the rotational direction and rotational amount detected by the torque sensor 29, and performs steering.

Further, when performing steering avoidance, the motor 37 applies steering torque to the lower shaft 43B according to the content of steering avoidance determined by the avoidance travel control unit 5, and performs steering.
Further, the steering unit 135 includes a reaction force motor 53. The reaction force motor 53 is controlled by the vehicle motion control unit 7. When the driver rotates the steering 41, the reaction force motor 53 applies a rotational torque in a direction opposite to the rotation to the upper shaft 43 </ b> A according to the rotational angle of the steering 41. The reaction force motor 53 has a function of generating an appropriate resistance when the driver rotates the steering wheel 41 and generating a steering feeling without a sense of incongruity.

In the step 6, the vehicle control device 1 of the present embodiment limits the rotation of the steering 41 in any one of the modes (i) to (iv) as in the first embodiment.
However, in the present embodiment, the rotation of the steering motor 41 is limited by controlling the rotation of the reaction force motor 53. That is, in the case of the mode (i), the steering 41 is prevented from rotating by not rotating the reaction motor 53.

In the case of the mode (ii), an upper limit is provided for the rotational speed of the steering 41 by providing an upper limit for the rotational speed of the reaction force motor 53.
In the case of the mode (iii), an upper limit is provided for the rotation amount of the steering 41 by providing an upper limit for the rotation amount of the reaction force motor 53.

In the case of the mode (iV), the rotation amount of the steering 41 per unit steering amount is reduced by reducing the rotation amount of the reaction force motor 53 per unit steering amount.
2. Effects of vehicle control device 1 According to the second embodiment described in detail above, the following effects are obtained in addition to the effects (1A) to (1D) of the first embodiment described above.

(2A) When executing steering avoidance, the vehicle control device 1 performs steering by the motor 37 and rotates the steering 41 by the reaction force motor 53. Therefore, the degree of freedom when restricting the rotation of the steering 41 is further increased.
<Other embodiments>
As mentioned above, although embodiment of this invention was described, this invention can take a various form, without being limited to the said embodiment.

  (1) In the first and second embodiments, the aspect of limiting the rotation of the steering 41 may be other than the above (i) to (iv). For example, as described in (ii) above, an upper limit may be provided for the rotational speed of the steering 41, and an upper limit may be provided for the amount of rotation of the steering 41 as described in (iii). Further, as described in (ii) above, an upper limit may be provided for the rotational speed of the steering 41, and the rotational amount of the steering 41 per unit steering amount may be reduced as in (iv). Further, as described in (iii), an upper limit may be provided for the rotation amount of the steering 41, and the rotation amount of the steering 41 per unit steering amount may be reduced as in (iv).

  (2) The vehicle control device 1 may have an automatic travel function for causing the host vehicle to travel along a preset route. During automatic traveling, steering is appropriately performed so that the host vehicle does not deviate from the route. The steering can be performed by the vehicle driving control unit 7 controlling the steering units 35 and 135 in the same manner as when steering avoidance is executed. When steering is performed during automatic traveling, the rotation of the steering 41 may be limited as in the first and second embodiments.

  (3) In step 4, it may be determined by means other than the torque sensor 29 whether or not the driver is holding the steering wheel 41. For example, a contact sensor provided on the steering 41 may determine whether the driver is holding the steering 41.

(4) The vehicle control device 1 may limit the rotation of the steering 41 regardless of whether or not the driver holds the steering 41.
(5) The functions of one component in the above embodiment may be distributed as a plurality of components, or the functions of a plurality of components may be integrated into one component. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function. Moreover, you may abbreviate | omit a part of structure of the said embodiment. In addition, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other embodiment. In addition, all the aspects included in the technical idea specified only by the wording described in the claim are embodiment of this invention.

  (6) In addition to the vehicle control device described above, a system including the vehicle control device as a constituent element, a program for causing a computer to function as the vehicle control device, a medium recording the program, a vehicle control method, and a rotation limit of a handle The present invention can also be realized in various forms such as a method.

DESCRIPTION OF SYMBOLS 1 ... Vehicle control apparatus, 3 ... Obstacle recognition unit, 5 ... Avoidance travel control unit, 7 ... Vehicle motion control unit, 9 ... Camera, 11 ... Millimeter wave radar, 13 ... Laser radar, 15 ... Sonar, 17 ... Locator, DESCRIPTION OF SYMBOLS 19 ... Four-wheel wheel speed sensor, 21 ... Steering angle sensor, 23 ... Front-back G sensor, 25 ... Left-right G sensor, 27 ... Yaw rate sensor, 29 ... Torque sensor, 31 ... Driving force control unit, 33 ... Brake control unit, 35 135 ... steering unit 37 ... motor 39 ... VGR motor 41 ... steering 43 ... steering shaft 43A ... upper shaft 43B ... lower shaft 45 ... rack and pinion 47 ... tie rod 49 ... wheel 51 ... Clutch, 53 ... Reaction force motor

Claims (6)

A vehicle control device (1) used for a vehicle including a steering unit (35, 135) for performing steering and a steering (41) rotating in conjunction with the steering,
A steering control unit (7) for steering using the steering unit;
In the first case where the steering control unit performs the steering as compared with the second case where the steering is performed due to the steering of the driver, the limiting unit (7) which limits the rotation of the steering accompanying the steering. )When,
A vehicle control device comprising: The vehicle control device according to claim 1,
In the first case, the limiting unit does not rotate the steering even if the steering is performed. The vehicle control device according to claim 1,
In the first case, the limiting unit provides an upper limit lower than that in the second case for the rotational speed of the steering and / or the amount of rotation of the steering. The vehicle control device according to claim 1,
In the first case, the limiting unit makes the amount of rotation of the steering per unit steering amount smaller than that in the second case. The vehicle control device according to any one of claims 1 to 4,
A determination unit (5) for determining whether the driver is holding the steering wheel;
The vehicle control apparatus according to claim 1, wherein the restriction unit performs the restriction on a condition that the determination unit determines that a driver is holding the steering wheel. The vehicle control device according to any one of claims 1 to 5,
It has an obstacle recognition unit (3) that recognizes obstacles,
The vehicle control apparatus, wherein the steering control unit performs the steering when the obstacle recognition unit recognizes an obstacle.