JP2010288449A - Apparatus and method for supporting parking - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To park a vehicle by a small parking labor even if a parking space is narrow for the vehicle having at least two steering wheels and at least two driving wheels which are driven independently to each other. <P>SOLUTION: A vehicle 1 has at least two driving wheels 11 which are driven independently to each other in order to ease a parking process to a parking space 3 for tandem parking. As a driving mechanism, for example, hub motors 13 are used. Here, the driving wheels 11 are two opposite wheels, that is, the wheels which are attached to both sides of a shaft. When the driving wheels 11 run in curves, one driving wheel 11 runs in an inner curve and the other driving wheel 11 runs in an outer curve. In order to ease the curve running and the steering running of the vehicle 1, the vehicle 1 has further at least two steering wheels. In this embodiment, the steering wheels are the ones attached to a steering shaft 15. By varying the direction of the steerable wheel 17 properly by the steering shaft 15, the wheels are moved, and the steering process or the rotating running of the vehicle is started. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a parking assistance device according to the first aspect of the present invention. The present invention also relates to a parking support method described in the superordinate concept of claim 8.

  Usually, the vehicle has a steering shaft and a drive shaft. In this case, a front drive vehicle in which the steered wheels are driven is distinguished from a rear drive vehicle that is not. All-wheel drive vehicles are also available on the market. Due to the concept of a drive mechanism with a single drive unit that drives the drive wheels via a cardan shaft and a differential gear, the vehicle can only curve along a limited radius arc. Thereby, the minimum area of the parking space required at the time of parking becomes settled, and the effort of the maneuvering at the time of putting a vehicle into a parking space can be estimated. In order to support the parking process, for example, a distance sensor is provided for determining the distance to obstacles before and after the vehicle. There are also sensors on the market that estimate the size of the parking space, and by setting the optimal steering angle for the driver during parking, or by automatically moving the vehicle to the parking space, parking is possible. It is also known to assist. However, these systems all assume that the minimum area of the parking space is predetermined. This is because the possible turning radius for curve traveling cannot be reduced.

  An object of the present invention is to enable parking in a narrow parking space with a small amount of maneuvering.

  This problem is that, in a parking assistance device that assists in entering and exiting a parking space of a vehicle having at least two steerable wheels and at least two drive wheels, each drive wheel is driven independently at a different rotational speed. Solved by.

It is a figure which shows the process (henceforth a warehousing process) which puts a vehicle into a parking space using the driving wheel driven to the opposite direction, respectively. It is a figure which shows the process (henceforth the unloading process) of taking a vehicle out of a parking space using the driving wheel driven to the opposite direction, respectively. It is a figure which shows the warehousing process by a driving wheel and a fixed wheel. It is a figure which shows the leaving process by a driving wheel and a fixed wheel. It is a figure which shows the warehousing process by the drive wheel driven rapidly and the drive wheel driven slowly. It is a figure which shows the leaving process by the drive wheel driven rapidly and the drive wheel driven slowly.

  In the present invention, “driven at different rotational speeds” means that each drive wheel can be driven in the same direction or in the opposite direction at different rotational speeds.

  By means of driving each drive wheel at a different number of revolutions, the vehicle can be driven with a smaller radius during curve travel than is possible with the drive concept known from the prior art. Thereby, for example, the number of times of entering and exiting the vehicle row can be reduced, and parking becomes easy. In addition, the vehicle can be parked in a narrower parking space with only a small amount of maneuvering effort compared to the prior art. A plurality of mutually independent drive wheels can be driven by an arbitrary drive concept. Advantageously, each drive unit for each drive wheel is positioned in the immediate vicinity of each drive wheel. Particularly preferably, a driving motor is attached to the hub of each driving wheel that is driven independently of each other. Hereinafter, this is referred to as a hub motor. The hub motor may be a known drive concept used, for example, a drive unit used in addition to the internal combustion engine, or may be the sole drive unit of the vehicle.

  Usually, the hub motor is configured as an electric motor. The energy required by the hub motor configured as an electric motor is formed by the internal combustion engine when used in a vehicle including the internal combustion engine, for example. However, the system of the invention advantageously comprises a vehicle with a hybrid drive mechanism comprising an internal combustion engine and an electric motor, for example a hub motor, or an electric drive mechanism powered by a fuel cell or a rechargeable storage battery. Used in different vehicles. Even in a vehicle including one internal combustion engine and at least one electric motor, a hub motor can be used for driving wheels in addition to the original drive concept or instead of the conventional electric motor. In electric drive mechanisms, hub motors are advantageously used in place of individual electric motors that generate drive energy. In addition, the electric motor can be used for driving the vehicle, and the hub motor can be used for supporting the entrance / exit process for the parking space independently from the electric motor. It is also advantageous to use a hub motor as the only drive means.

  The use of a hub motor has the advantage that one wheel can be driven independently of the other wheel. For example, each wheel can be driven in the same or opposite direction at the same or different speeds. In particular, by driving multiple wheels in opposite directions, you can get a very small minimum rotation circle, save parking space, and park in a small parking space without much effort in maneuvering Can do.

  The vehicle drive mechanism can drive two wheels or four wheels. The drive wheels are usually connected to the vehicle shaft. In a case where there are two steerable wheels, if the two wheels are driven, the two drive wheels may be steerable wheels or fixed wheels. In addition to the case where there are two steerable wheels, there may be a case where all four wheels of the vehicle can be steered.

  In order to avoid the trouble of the driver individually driving each drive unit, the required speed of each drive wheel to be driven individually is determined based on the steering angle, and each drive unit for each drive wheel to be driven individually is determined accordingly. It is advantageous if a control unit is provided for driving.

  In order to ensure that each wheel is driven accordingly when entering or exiting the vehicle in parallel parking or horizontal parking, advantageously the driver inputs to the control unit that the vehicle is to run in parking mode. To inform. Instead, for example, based on the speed of the steering angle, the vehicle speed or other parameters representing parking, it is automatically identified whether the process of entering and exiting the vehicle in parallel parking or horizontal parking is performed. Accordingly, automatic switching to the parking mode can be performed.

  The present invention also relates to a parking assistance method for assisting entry and exit of a parking space of a vehicle having at least two steerable wheels and at least two drive wheels driven independently of each other. According to the invention, the drive wheels driven independently of each other are driven at different speeds based on the steering angle and / or in different directions if the steering angle is completely defined. Is done.

  According to the method of the present invention, the drive wheels can be driven independently of each other, for example, in opposite directions to each other, so that it is possible to easily enter and leave the parking space even in a narrow parking space without troublesome maneuvering. .

  Advantageously, when the steering angle increases, the speed of the drive wheels traveling in the inner circle is first reduced to a stationary state at the set steering angle and then increases in the opposite direction when the steering angle further increases. Is done. The steering angle at which the drive wheels traveling on the inner circle are stationary changes depending on the vehicle speed. When the speed of the steering angle increases, this increases the turning angle of the steerable wheel. On the other hand, at a low speed and a small steering angle, the stationary state of the drive wheels traveling on the inner circle can be obtained. In this way, the parking process can be adapted to the selected speed.

  In order to facilitate the parking process for the driver, the steering angle and the speed demand set by the driver are advantageously supplied to the control unit as input quantities and are individually driven based on the steering angle and the speed demand. The required speed of each drive wheel is determined, and each drive unit for each drive wheel driven individually is driven accordingly.

  The speed demand from the driver is usually determined by the accelerator pedal. However, the speed request can be set by any other device such as a manually operated switch.

  The speed of each drive wheel is controlled by the number of rotations of each hub motor, for example. For this purpose, the rotational speed of each drive wheel is measured and compared with the rotational speed for the required speed. When the rotational speed measured in this way is excessively high, the rotational speed is reduced, and when it is excessively low, the rotational speed is increased.

  Embodiments of the invention are illustrated and described in detail below.

  FIG. 1 shows a warehousing process using a plurality of wheels driven in directions opposite to each other.

  The vehicle 1 equipped with the parking assist device of the present invention travels in the backward direction and is going to park in parallel in the parking space 3. In this embodiment, a parallel parking space 3 exists between the front vehicle 5 and the rear vehicle 7. The side of the parallel parking space 3 is divided by, for example, a curbstone 9.

  The vehicle provided with the parking assist device of the present invention may be a transport vehicle that transports personnel and luggage. These transport vehicles usually have four wheels if they are small, but may have about ten wheels if they are large. In the latter case, the wheels are generally mounted on three shafts, and in particular, two wheels are mounted on both sides of the rear shaft as twin wheels.

  In order to facilitate the process of entering the parking space 3 for parallel parking, the vehicle 1 has at least two drive wheels 11 that are driven independently of each other. For example, a hub motor 13 is used as the drive mechanism. Here, the drive wheels 11 are two wheels facing each other, that is, wheels on both sides of one shaft, and one travels in an inner circle and the other travels in an outer circle during curve traveling.

  In order to facilitate the vehicle 1 traveling in a curve and steering, the vehicle 1 further has at least two steerable wheels. In this embodiment, the steerable wheel is a wheel attached to the steerable shaft 15. By changing the direction of the steerable wheel 17 by the steerable shaft 15, the wheel is moved to start the steering process or the turning of the vehicle.

  In this embodiment, the drive wheels 11 that are driven independently of each other are not attached to the steerable shaft 15. In a vehicle having a standard structure in which the front shaft is the steerable shaft 15, the drive wheels 11 that are driven independently from each other are rear wheels. Alternatively, the steerable wheels can be driven or all four wheels can be driven.

  When the front wheels are driven by, for example, an internal combustion engine and the rear wheels are driven by individual drive mechanisms, the vehicle is moved by drive wheels 11 attached to the rear axle and driven independently of each other during the warehousing process. . In the rear drive vehicle, in addition to the rear shaft driven by the internal combustion engine, a drive mechanism for independently driving the two rear wheels can be provided. When the vehicle is not driven by a central internal combustion engine and all front wheels, rear wheels, or all four wheels are driven by a hub motor, all the drive wheels that are driven independently from each other are driven at different rotational speeds in the warehousing process. be able to. In the case of a four-wheel drive vehicle, the speed of the individual wheels is adapted to the position of each wheel relative to the direction of travel of the vehicle and the turning radius to be traveled.

  In the case of a rear drive vehicle, when the rear wheels are driven independently from each other by a hub motor, for example, the driving of each driving wheel 11 by the internal combustion engine and the driving by the hub motor 13 can be switched by appropriate switching.

  In a vehicle or a hybrid vehicle provided with an electric drive mechanism, only the hub motor 13 may be provided as a vehicle drive mechanism. In the case of all-wheel drive, a hub motor may be provided on the front wheel, that is, the wheel of the steerable shaft 15, so that all-wheel drive and front-wheel drive can be switched. The corresponding switching can be adjusted, for example, by the driver. In a vehicle equipped with a hybrid engine, for example, an electric current necessary for driving the hub motor 13 is generated by an internal combustion engine. Advantageously, in a vehicle with a hybrid engine, the wheels 11 are driven by an internal combustion engine or an electric motor.

  If the vehicle has five or more wheels and there are two rear axles, for example, all the rear wheels may be driven, or only the two rear wheels facing each other may be driven. When entering and leaving a parking space (incoming or outgoing), it is generally sufficient to drive only two wheels.

  FIG. 1 shows a warehousing process using a plurality of hub motors 13 driven in different directions. Here, the hub motor of the wheel traveling on the outer circle drives the wheel so that the vehicle 1 enters the parking space 3 for the parallel parking in the backward direction. At the same time, the hub motor of the wheel traveling in the inner circle drives the corresponding wheel in the opposite direction to the wheel traveling in the outer circle. As a result, the vehicle can be turned with a very small radius, and even in a small parking space, the vehicle can be easily parked without troublesome turning-back, width adjustment, or vehicle operation. The speeds of the plurality of wheels rotating in opposite directions may be the same or different. In general, the speed of the wheels traveling in the inner circle is smaller than the speed of the wheels traveling in the outer circle, thereby determining the traveling direction of the vehicle. However, the wheel speed also changes depending on the steering angle, that is, the angle of the steerable wheel 17 attached to the steerable shaft 15.

  FIG. 2 shows a delivery process using a plurality of wheels driven in opposite directions. The unloading process shown in FIG. 2 corresponds to the receiving process shown in FIG. The difference from the case of FIG. 1 is that the drive wheels 11 driven independently of each other are each driven in the opposite direction. That is, the wheels traveling in the outer circle are driven to move the vehicle forward, and the wheels traveling in the inner circle are driven to move the vehicle backward in the opposite direction.

  1 and 2, the movement directions of the drive wheels 11 that are driven independently of each other are indicated by arrows. Here, the movement direction of the wheel traveling in the outer circle is indicated by an arrow 19, and the movement direction of the wheel traveling in the inner circle is indicated by an arrow 21. In this case, each drive wheel can be driven at the same peripheral speed or a different peripheral speed, and each peripheral speed is determined according to the speed of the steering angle of the steerable wheel 17. In general, the speed of the wheel traveling in the inner circle is smaller than the speed of the wheel traveling in the outer circle. However, as described above, these may be the same speed.

  In particular, in a narrow parking space, in addition to driving as in the illustrated embodiment, it is possible to determine the direction of movement of the vehicle by increasing the peripheral speed of the drive wheels facing away from the curb 9. In this case, the steering angle and thus the steerable wheel 17 must face in the other direction. When taking the vehicle out of the parking space, in order to facilitate the process, the vehicle is moved along a very small arc and is first positioned obliquely with respect to the direction of travel.

  3 and 4 show a warehousing process and a warehousing process in which only one wheel is driven. Each of the driving wheels 11 is located on the outer circle. The direction of the drive wheel 11 is determined according to the traveling direction of the vehicle. The wheel (non-driving wheel) facing the driving wheel may be stationary by being braked by, for example, the hub motor 13 or may move independently from the driving wheel without load based on the steering angle of the steerable wheel. May be. The warehousing process of FIG. 3 and the warehousing process of FIG. 4 differ only in the rotation direction of the drive wheels 11.

  5 and 6 show another variation of the warehousing process and the warehousing process. In the embodiment shown in FIGS. 5 and 6, the drive wheels driven independently of each other are driven at different speeds. In this case, the speed of the wheels traveling in the outer circle is greater than the speed of the wheels traveling in the inner circle. Due to the different speeds of the drive wheels driven in the same direction, the radius of the traveling wheel becomes larger than the radius of the stationary wheel, as shown in FIGS. Further, the state of the wheel driven in the opposite direction is as shown in FIGS.

  Similarly, the speed of the drive wheel is determined according to the steering angle of the steerable wheel 17. As the steering angle of the steerable wheel decreases, the speed difference between the plurality of drive wheels driven independently from each other also decreases.

  Due to the different speeds of the wheels oriented in the same direction or opposite directions, as shown in FIGS. It can be adjusted to the dimensions. As the distance between the front vehicle 5 and the rear vehicle 7 increases, the radius of the circle that the vehicle follows when parking can be increased. The drive mechanism drives the wheels in the same direction if the turning radius is large, and drives the wheels in the opposite direction if the turning radius is small.

  In the embodiment shown in FIGS. 1 to 6, the front wheels are steerable wheels and the rear wheels are driven independently of each other, but the front steerable wheels are driven independently of each other to The wheel may not be driven. In addition, the front and rear wheels can be driven independently of each other and the speed of the individual wheels can be controlled to achieve the desired curve radius for the parking process. Further, instead of the front wheels, the rear wheels can be steered, or all four wheels can be steered. If the two wheels of the vehicle are steerable and all four wheels can be driven independently of each other, for example, the steerable wheels can be moved at a different speed than the unsteerable wheels. Each speed is determined according to the desired curve radius.

  DESCRIPTION OF SYMBOLS 1 Own vehicle, 3 Parking space, 5 Front vehicle, 7 Rear vehicle, 9 Curb, 11 Drive wheel, 13 Hub motor, 15 Steering shaft, 17 Steerable wheel, 19, 21 Wheel direction of movement

Claims (10)

In a parking assistance device for assisting the vehicle (1) having at least two steerable wheels (17) and at least two drive wheels (11) to enter and leave the parking space,
Each driving wheel is driven at different rotational speeds independently from each other in the parking mode.   The parking assistance device according to claim 1, wherein the driving wheels driven at different rotational speeds independently of each other are driven in the same direction or in opposite directions.   The parking assist device according to claim 1 or 2, wherein each of the driving wheels is driven by a hub motor (13).   The parking assistance device according to any one of claims 1 to 3, wherein the vehicle has at least one electric drive mechanism.   The parking assist device according to any one of claims 1 to 4, wherein the vehicle has a hybrid drive mechanism including one internal combustion engine and at least one electric drive mechanism.   2. A control unit is provided for determining the required speed of each individually driven wheel based on the steering angle and correspondingly driving the drive unit (13) for each individually driven wheel. The parking assistance device according to any one of claims 1 to 5.   The parking assistance device according to any one of claims 1 to 6, wherein the parking mode is set by a driver or based on a steering angle and a vehicle speed. In a parking assistance method for assisting entry and exit of a vehicle (1) having at least two steerable wheels (17) and at least two drive wheels (11) driven independently of each other,
A parking assistance method, wherein each driving wheel is driven at a different speed and / or a different direction according to a steering angle.   When the steering angle increases, the speed of the driving wheel traveling in the inner circle is first reduced to a stationary state at a set steering angle, and then increased in the opposite direction when the steering angle further increases. Item 9. The parking support method according to item 8.   The steering angle and the speed request set by the driver are supplied as input quantities to the control unit, and the control unit obtains the required speed of each drive wheel that is individually driven from the steering angle and the speed request, and 10. A parking assistance method according to claim 8 or 9, wherein the drive unit (13) for each individually driven wheel is driven accordingly.

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