JP2011189874A - Parking support method and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To estimate the tire position, direction, wheelbase, minimum turning radius, and the like of a vehicle by identifying the tire and body of the vehicle, so as to enhance an instruction method accuracy to the vehicle. <P>SOLUTION: A guided vehicle operated by a guided person is guided from a parking start position to a parking end position. A parking guidance device is provided on the outside of the guided vehicle to acquire, by sensing, at least the wheelbase in addition to the vehicle overall length, vehicle overall width as vehicle specification, and acquire current position, direction, and steering angle of the vehicle as vehicle condition. The parking guidance device calculates ideal vehicle trajectory and ideal driving operation based on the acquired vehicle specification and vehicle condition, and vocally instructs the guided person. The guided person operates the vehicle based on the vocal instruction from the parking guidance device. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a parking assistance method and system for guiding a guided vehicle operated by a guided person from a parking start position to a parking end position.

  Currently, research on ITS (Intelligent Transport Systems), which uses electronics and information and communication technology to make intelligent and networked, is considered as a system for solving various road traffic problems and improving efficiency. It is. In this context, research on automatic driving and driving assistance related to AVCSS (Advanced Vehicle Control and Safety Systems), which is expected to be essential solutions for traffic accidents and traffic jams, is also actively conducted.

  In recent years, driving support is important in securing safe and efficient means of transportation in response to the increase in elderly drivers, who are said to have large variations in driving ability. Support systems are expected to become even more important in the future. The present inventors previously acquired a vehicle position and travel information from the outside, and performed a parking guidance by voice, so that a parking guidance method and system aimed at solving the limit of in-vehicle costs and options (Patent Document 1).

  FIG. 4 is a diagram illustrating the concept of the vehicle guidance system described in Patent Document 1. This vehicle guidance system includes a parking guidance device outside the guided vehicle, acquires the state of the vehicle by sensing, and from the parking start position to the parking end position with respect to the guided vehicle operated by the guided person. Induce. The parking guidance device calculates a vehicle ideal trajectory and an ideal driving operation based on the acquired vehicle state, detects an obstacle, and gives a voice instruction to the guided person. The guided person performs a vehicle operation based on a voice instruction from the parking guidance device. Thus, the basic part (parking guidance device) of the vehicle guidance system is not mounted on the vehicle to be supported. The basic functions required for parking guidance devices such as environment recognition functions, communication functions, and guidance functions, including position and status, are placed outside the vehicle, and information from them is used for environment recognition functions. They are trying to expand and reduce in-vehicle costs.

  FIG. 5 is a diagram for explaining the operation of the vehicle guidance system shown in FIG. In the exemplary vehicle guidance system, it is necessary to set the laser surface for acquiring the vehicle state to a height that does not hit the wheel house of the vehicle, and depending on the target vehicle, the height limit is large. . The laser surface had to be above the wheelhouse and below the window. In addition, since it is difficult to estimate the wheelbase, it is necessary to give instructions according to feedback control in the vehicle steering control instruction method.

  In addition, there has been no support system for multistory parking lots. A three-dimensional parking lot is not a support target in an in-vehicle system in which a support system is mounted on a vehicle, and parking is particularly difficult.

JP 2008-279899 A JP 2008-257002 A

Ohmae, Hashimoto, Fujioka, Shimizu, Research on motion control of automatic driving in a premises with a parking lot, Automobile Engineering Society Proceedings Vol.35-3, (2004), pp.235-240

  The conventional technique obtains the position and orientation of the vehicle from the outside, and it is difficult to estimate the wheel base value that affects the turning radius of the vehicle. In addition, the correct current direction (steering angle) of the tire cannot be estimated, and is estimated to be the same as the width of the body, which has restrictions on steering instructions.

  An object of the present invention is to make a vehicle indication method more accurate by estimating a vehicle tire position and orientation, a wheel base, a minimum turning radius, and the like by identifying a vehicle tire and a body.

  The parking support method of the present invention for guiding the guided vehicle operated by the guided person from the parking start position to the parking end position includes a parking guidance device outside the guided vehicle, In addition to the full width of the vehicle, at least the wheel base is acquired by sensing, and the current position, orientation, and steering angle of the vehicle are acquired as the vehicle state. The parking guidance device calculates a vehicle ideal trajectory and an ideal driving operation based on the acquired vehicle specification and vehicle state, and gives a voice instruction to the guided person. The vehicle is operated based on the voice instruction.

  Moreover, the parking assistance system of this invention is provided with the parking guidance apparatus which has the environment recognition function including a vehicle state, a communication function, and a guidance function outside a to-be-guided vehicle. By the environment recognition function, at least the wheel base is acquired by sensing in addition to the vehicle total length and the vehicle total width as the vehicle specification, and the current position, direction, and steering angle of the vehicle are acquired as the vehicle state. The guidance function includes means for calculating a vehicle ideal trajectory and an ideal driving operation based on the acquired vehicle specification and vehicle state, and the communication function calculates the result calculated and detected by the guidance function to the guided person. Means for giving a voice instruction is provided.

  A wheel range is estimated by using a laser range finder as a sensor for measuring the vehicle specifications, setting the height at which the generated laser hits the wheel house, and detecting the tire using the difference in reflectance. The means for giving a voice instruction is a communication device for giving an operation instruction via a radio receiver provided in the vehicle, or a speaker for directly giving a voice instruction.

  By recognizing the positions of the two front and rear tires, the size between them becomes the wheel base. The vehicle's turning radius in a low-speed situation without slipping, such as when parked, is determined by the wheelbase and steering angle, so it was necessary to switch back due to a delay in the parking operation instruction or an error in the driver's operation. It is possible to guess in advance the case. In addition, when the distance between the sensor and the tire is close and there are many lasers, the steering angle of the current tire can be estimated, and in that case, the steering angle can be accurately instructed to the driver. It becomes.

  The laser may be applied within the range of the height of the size of the tire, and a general vehicle excluding special vehicles and large vehicles can be handled at almost the same height. Until now, special vehicles and large vehicles are excluded. It is also possible to provide vehicle support from outside in a multi-story parking lot or the like.

It is a figure which shows the concept of the parking assistance system comprised based on this invention. It is a figure which illustrates the parking assistance system structure comprised based on this invention. It is a flowchart which shows the flow of operation | movement of a parking guidance system. It is a figure which shows the concept of the vehicle guidance system of patent document 1. As shown in FIG. It is a figure explaining operation | movement of the vehicle guidance system shown in FIG.

  FIG. 1 is a diagram showing the concept of a parking assistance system configured according to the present invention. As shown in this figure, the parking support system is not mounted on the vehicle where the basic part (parking guidance device) is supported, but the arrangement is not only fixed as infrastructure, but also installed in other vehicles It is also possible to do. The basic functions required for the parking guidance device can be said to be vehicle specifications such as a vehicle wheelbase, environment recognition function including vehicle position / state, communication function, and guidance function. In the present invention, these functions are arranged outside the vehicle, and information from them is used to expand the environment recognition function and reduce the in-vehicle cost. However, it is also conceivable to use distributed functions and onboard functions. Since the guidance is from the outside, the main guidance function is the outside, which can be expected to reduce the burden on the in-vehicle device, reduce costs, and provide unified judgment information to a plurality of vehicles. As a sensor for measuring the vehicle state and basic information (position, direction, speed, yaw rate, vehicle width, vehicle length, wheel base, steering angle), a laser range finder (LRF: manufactured by SICK) can be used. The laser range finder irradiates a laser at a certain angle in the horizontal direction and calculates the distance.

  The present invention detects the wheel base by setting the height at which the laser strikes the wheel house and detecting the tire using the difference in reflectance. In this way, it is possible to estimate the wheel base that is one of the specifications of the vehicle by applying the laser surface to the tire and detecting the position of the tire. The wheel base is a value largely related to the minimum turning radius of the vehicle, and thus can be guided with high accuracy. In this specification, “wheel base” means the distance between the front wheel shaft (tire center) and the rear wheel shaft (tire center), and “wheel house” means that the tire (wheel) is It is used as a term that means a space reserved for rolling while attached to the vehicle body.

  FIG. 2 is a diagram illustrating a configuration of a parking assistance system configured according to the present invention. The illustrated parking assistance system includes a parking guidance device fixed to a parking lot and an FM radio provided in the vehicle. The parking guidance apparatus further includes a calculator (arithmetic device) having an arithmetic function, a vehicle state (position / orientation / steering angle) estimation sensor and an obstacle detection sensor, and a communication device (FM transmitter) connected to the arithmetic device. It consists of. A speaker may be used instead of the communication device. In the present invention, the FM transmitter provided in the semi-fixed parking guidance device is used to give an operation instruction only by voice via the FM radio (car stereo).

  The communication function between the vehicle and the parking guidance device is merely a means of information transmission, and does not necessarily indicate a wireless communication device, but may be transmitted by sound from an external speaker although it is primitive. However, high reliability is required for applications related to safety. The guidance function can be considered in various ways depending on the application described later. In addition to the construction of a guidance algorithm that takes into account the delay in guidance control, the method of presenting information to the driver, robustness, fail-safe, etc. are also important. By estimating the information from the vehicle that receives the guidance support by the external device, it becomes possible to simplify the communication means and greatly expand the applicable vehicles.

FIG. 3 is a flowchart showing an operation flow of the parking guidance system. The following describes the system flow order.
1) The guided person (driver) starts operation and moves the vehicle (driven vehicle) to the parking start position.
2) The parking guidance device starts guidance, and instructs the driver to start by a signal such as voice.
3) The parking guidance device first acquires the wheel base, the total vehicle length, and the total vehicle width, which are vehicle specifications, by sensing. In addition, the vehicle state is acquired by sensing, and the vehicle position, direction, speed, yaw rate, and steering angle are acquired. The speed and yaw rate can be calculated from the vehicle position and orientation.
4) Upon receiving the start instruction, the driver operates the vehicle.
5) The parking guidance device calculates the vehicle ideal trajectory and the ideal driving operation from the wheel base, the current position and orientation of the vehicle, and the steering angle, and detects an obstacle. Then, a simplified voice instruction is given to the driver.
6) The driver ends the vehicle movement after performing the vehicle operation based on the voice instruction.
7) The driver receives the parking assistance end instruction from the parking guidance device and confirms the completion of parking. Then, the parking guidance device ends the parking assistance.

  From the parking guidance device to the guided vehicle, using the relative relationship between the guided vehicle and the position and orientation of the target parking space, the steering change amount and the driving braking amount for accurately parking are calculated from the control algorithm, A function to provide as guidance information is required. In the case of automatic parking, the actuator is driven by this information, but in the case of a driving instruction to the driver by a human machine interface (HMI), it is used as a basis for the presentation information.

  The vehicle parking guidance control algorithm can calculate the amount of steering change using the control method used in Non-Patent Document 1. The feature of this control method is that it does not depend on geometric parameters such as the wheelbase of the vehicle body and mechanical parameters such as cornering power, and thus can actually deal with an unspecified number of vehicles. Information on the position and orientation of the parking space can be acquired by the parking support system using a map database or the like. As described in Non-Patent Document 1, the position of the center of gravity can be used for the position of the guided vehicle, but the center position can also be used simply.

  As an information instruction method, a steering instruction using sound is performed according to the target steering angle calculated by the external guidance device, the current steering angle, and the vehicle specification. Simple voice instructions (several kinds of instructions such as slightly right and large right) are confusing for the driver and use a simple voice instruction method for external assistance.

  Vehicle tires are securely installed on the ground, and vehicles (RVs and light vehicles) have various tire sizes, but the sensor should be installed at the approximate center height of the tire and level with the ground. Thus, tire detection is possible from most vehicle estimates and laser reflectivity.

  Actually, it was possible to recognize tires and wheels using an ordinary vehicle, and also recognize the vehicle wheelbase. In addition to the distance sensor, it is possible to estimate them by using the reflectance with the object.

  For this reason, first, an approximate position of the vehicle is specified from the value obtained from the laser sensor. A tire in the wheel house is detected by detecting a candidate wheel house part from the approximate position of the vehicle and detecting a part having a low laser reflectivity in the wheel house candidate part. At this time, since the reflectance is affected by the distance, the comparison is performed by multiplying the reflectance by the coefficient of the distance. By estimating the distance of the detected tire, the length of the wheelbase is calculated. Further, by calculating the difference between the detected front tire angle and the vehicle angle, the tire direction, that is, the steering angle is calculated. In the conventional guidance method, a control guidance algorithm that does not use the wheel base or the current steering angle is used. However, the present invention uses a technique for estimating the wheel base and the steering angle, thereby providing a more accurate control algorithm. Will be applied.

Claims (5)

In the parking assistance method for guiding the guided vehicle operated by the guided person from the parking start position to the parking end position,
A parking guidance device is provided outside the guided vehicle, and as a vehicle specification, at least the wheel base is acquired by sensing in addition to the total vehicle length and the total vehicle width, and the current vehicle position, direction, and steering angle are obtained as the vehicle state. Get
The parking guidance device calculates a vehicle ideal trajectory and an ideal driving operation based on the acquired vehicle specification and vehicle state, and gives a voice instruction to the guided person.
A parking assistance method in which a guided person performs a vehicle operation based on a voice instruction from the parking guidance device.   A wheel range is estimated by using a laser range finder as a sensor for measuring the vehicle specifications, setting the height of the generated laser to hit the wheel house, and detecting a tire using a difference in reflectance. The parking support method according to Item 1. In the parking support system for guiding the guided vehicle operated by the guided person from the parking start position to the parking end position,
A parking guidance device having an environment recognition function including a vehicle state, a communication function, and a guidance function outside the guided vehicle,
As a vehicle specification by the environment recognition function, in addition to the vehicle total length and the vehicle total width, at least the wheel base is acquired by sensing, and as the vehicle state, the current position, orientation, and steering angle of the vehicle are acquired,
The guidance function includes means for calculating a vehicle ideal trajectory and an ideal driving operation based on the acquired vehicle specification and vehicle state,
The communication function includes means for giving a voice instruction to the induced person on the result calculated and detected by the guidance function.
A parking assistance system consisting of   A wheel range is estimated by using a laser range finder as a sensor for measuring the vehicle specifications, setting the height of the generated laser to hit the wheel house, and detecting a tire using a difference in reflectance. Item 5. The parking assistance system according to item 4.   5. The parking assistance system according to claim 4, wherein the voice instruction means is a communication device that gives an operation instruction via a radio receiver provided in a vehicle, or a speaker that directly gives an instruction by voice.