Vehicle Control Device and Automatic Parking System

During automated valet parking, when a parking facility is not spacious it is impossible to avoid null-point positions. Therefore, this vehicle control device is equipped with: a wireless communication unit for acquiring, from a control center by means of wireless communication, a null point indicating a position at which wireless communication is poor in a parking facility, and instruction information for controlling a vehicle in the parking facility; and an automatic driving control unit for moving the vehicle until the vehicle has escaped a null point and then stopping the vehicle, when the instruction information acquired by the wireless communication unit is an instruction for stopping the vehicle and the instructed stopping position is a null point.

TECHNICAL FIELD

The present invention relates to a vehicle control device and an automatic parking system.

BACKGROUND ART

In recent years, vehicle control devices that automatically drive vehicles have been developed. As examples thereof, there are known inter-vehicle distance keeping travel control that maintains a constant inter-vehicle distance from a preceding vehicle that travels on the front side while recognizing the front of the vehicle and travel lane keeping control that performs travel control so as not to deviate from a travel lane of a vehicle, for example. Furthermore, as an advanced type thereof, studies have been conducted on automated valet parking that automatically parks a vehicle in a parking facility of a building by automatic driving without being operated by a passenger.

In the automated valet parking, instruction information, such as a vehicle entry/exit instruction with respect to the parking facility, a vehicle stop instruction, and a vehicle start instruction, is transmitted to the vehicle by means of wireless communication which is used for C2X (Car-to-X)/V2X (Vehicle-to-X) and the like as a mobile phone network and road-to-vehicle/vehicle-to-vehicle communication from a control center. The vehicle stops, starts, and performs parking in the parking facility by automatic driving according to the instruction information. For example, when the instruction information is parking of the vehicle, the vehicle travels to a designated parking position by automatic driving and is parked at the designated parking position.

In the wireless communication, however, a direct wave transmitted from the control center and an interference wave overlap with each other at a reception site to cancel each other so that a null point is generated. At this null point, the interference wave changes due to a change in an environment of a parked vehicle or the like, and the null-point position also changes due to this change. Further, it is difficult for the control center to perform transmission and reception with the vehicle by wireless communication at the null point. For example, when a stop instruction is received from the control center for a certain region before the vehicle is parked at the designated parking position, the vehicle during the automatic driving is stopped. At this time, if the vehicle stops at the null point, the wireless communication is not possible even if there is a start instruction from the control center, and thus, the vehicle fails to restart and stays there.

PTL 1 describes an in-vehicle computer that transmits null point position information to a vehicle in advance and performs automatic parking based on the position information and calculates a movement trajectory of the vehicle so as to avoid a null-point position.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

With the technique described in PTL 1, it is difficult to avoid the null-point position when a parking facility is not spacious.

Solution to Problem

The vehicle control device according to the present invention includes: a wireless communication unit that acquires a null point indicating a position at which wireless communication is poor in a parking facility and instruction information for controlling a vehicle in the parking facility from a control center by means of wireless communication; and a control unit that moves the vehicle until the vehicle has escaped the null point and then stops the vehicle when the instruction information acquired by the wireless communication unit is an instruction for stopping the vehicle and an instructed stopping position is the null point.

An automatic parking system according to the present invention includes a vehicle control device and a control center that performs wireless communication with the vehicle control device.

Advantageous Effects of Invention

According to the present invention, it is possible to prevent the vehicle from stopping at the null point even when the parking facility is not spacious.

DESCRIPTION OF EMBODIMENTS

FIG. 1is a configuration diagram of a vehicle100. The vehicle100includes various external-environment sensors101, various actuators102, an automatic driving control unit103, a host vehicle position estimation unit104, a wireless communication unit105, an antenna106, and a null point determination unit107.

The various external-environment sensors101include a camera, a millimeter wave radar, an infrared radar, and the like in order to detect an obstacle and the like and enable automatic driving of the vehicle100.

The various actuators102include an engine that drives the vehicle, a brake that brakes the vehicle, and the like, and control the power of the vehicle100.

The automatic driving control unit103controls the various actuators102based on information from the various external-environment sensors101and the like, and causes the vehicle100to enter or exit a parking facility by automatic driving.

The host vehicle position estimation unit104estimates a current position of the vehicle100from information such as a global positioning system (GPS), a Global Navigation Satellite System (GNSS), and a gyro sensor, and outputs the information on the current position to the automatic driving control unit103and the like.

The wireless communication unit105performs wireless communication with a control center200, which will be described later, via the antenna106, and receives instruction information such as stop, start, entry, and exit of the vehicle100from the control center200, for example. Further, a detailed map of the parking facility and information indicating a null-point position are received from the control center200. The wireless communication unit105transmits/receives information by means of wireless communication which is used for C2X (Car-to-X)/V2X (Vehicle-to-X) or the like as a mobile phone network or road-to-vehicle/vehicle-to-vehicle communication.

Further, the wireless communication unit105includes an RSSI detection unit115. The RSSI detection unit115detects a reception signal intensity indicator (RSSI) of the wireless communication unit105.

The null point determination unit107stores the null point received from the control center200via the wireless communication unit105. The null point is position information represented by latitude, longitude, and the like. Further, the null point determination unit107acquires the current position of the vehicle100from the host vehicle position estimation unit104. Then, the null point determination unit107acquires the reception signal intensity detected by the RSSI detection unit115, and determines that the vehicle100has escaped the null point if the reception signal intensity exceeds a threshold along with the movement of the vehicle100from the null point. This determination result is output to the automatic driving control unit103, and driving control of the vehicle100is performed according to the determination result. The reception signal intensity detected by the RSSI detection unit115is sequentially transmitted to the control center200via the wireless communication unit105together with the current position information acquired by the host vehicle position estimation unit104.

FIG. 2is a configuration diagram of the control center200. The control center200includes a map information storage unit201, a null point storage unit202, a management control unit203, a wireless communication unit204, and an antenna205.

The map information storage unit201stores the detailed map of the parking facility. This detailed map also includes arrangement information of vehicles parked in the parking facility.

The null point storage unit202stores the null point of the parking facility. A direct wave and an interference wave of wireless communication are different depending on the arrangement of vehicles parked in the parking facility, and thus, the null point of the parking facility is also different. The null point storage unit202stores the null point of the parking facility in association with the arrangement information of vehicles parked in the parking facility. Then, when the vehicle100enters or exits, a null point corresponding to current arrangement information of vehicles parked in the parking facility is read out.

The management control unit203instructs entry, exit, stop, start, and the like to the vehicle100so as to achieve the consideration of safety and smooth operation in response to the arrangement of vehicles parked in the parking facility and the movement of other vehicles. Further, the management control unit203accumulates the reception signal intensity transmitted from the vehicle100and the position information thereof, and updates the null point corresponding to the vehicle arrangement information. Specifically, mapping is performed including a site where the reception signal intensity is equal to or greater than the threshold and a site where the reception signal intensity is less than the threshold so that information has not been transmitted, and the null-point position indicating the position where the wireless communication in the parking facility is poor is determined on the map. Then, the null point is stored in the null point storage unit202in association with the vehicle arrangement information.

The wireless communication unit204performs wireless communication with the vehicle100via the antenna205, and transmits instruction information such as stop, start, entry, and exit from the control center200to the vehicle100, for example. Further, the control center200transmits the detailed map of the parking facility and the information indicating the null-point position.

Next, the operation of the present embodiment will be described with reference toFIGS. 3 to 5.

FIG. 3is a view illustrating vehicle positions in a parking facility301, and illustrates an outline of vehicle parking using automated valet parking.

In the parking facility301, the control center200is installed near a carriage porch303, vehicles100-bto100-dare parked, and a vehicle100-eis traveling. The vehicle100-ais stopped near the carriage porch303and waits for the entry. Each of the vehicles100-ato100-ehas the configuration illustrated inFIG. 1. Each of the vehicles100-ato100-eperforms wireless communication with the control center200, travels in the parking facility301by automatic driving, and is caused to enter or exit a parking spot by automated valet parking.

In the automated valet parking, a driver stops the vehicle100-aat a stopping position304near the carriage porch303and gets off. If another passenger is present, the passenger also gets off in the same manner. The driver instructs the control center200to start the automated valet parking using a mobile phone or the like. This instruction may be made via a voice, or a command may be transmitted.

The control center200searches for a route310to a parking position307and instructs the vehicle100-ato start. When encountering the other vehicle100-eat a position305in the middle of the route310, the vehicle100-areceives a stop instruction from the control center200. At this time, the vehicle100-adetermines whether or not the position305is a null point, and stops at the position305if it is not the null point. When it is determined as the null point, the vehicle100-amoves to a position where the vehicle100-ahas escaped the null point as will be described later.

Thereafter, the vehicle100-afurther advances along the route310upon receiving a start instruction from the control center200.

Further, it is assumed that a stop instruction is received from the control center200at a position308near the parking position307. If the position308corresponds to the null point provided from the control center200, the vehicle100-adoes not stop at the position308, and the vehicle100-amoves at the slowest speed. Further, if the reception signal intensity detected by the RSSI detection unit115of the vehicle100-ais equal to or greater than the threshold, it is determined that the vehicle100-ahas escaped the null point, and the vehicle100-astops at the position309. Thereafter, the vehicle100-ais parked at the designated parking position307upon receiving a start instruction for parking.

When the vehicle100-ais parked at the designated parking position307, the RSSI detection unit115of the vehicle100-adetects the reception signal intensity and confirms that the reception signal intensity is equal to or greater than the threshold. If the reception signal intensity is equal to or greater than the threshold, parking is completed at this position. When the reception signal intensity is less than the threshold, the vehicle100-amoves to a position where the reception signal intensity is equal to or greater than the threshold, for example, a position309, asks the control center200to change the parking position, and changes the parking position according to an instruction from the control center200.

During the traveling along the route310, the vehicle100-asequentially transmits the reception signal intensity detected by the RSSI detection unit115to the control center200by means of wireless communication together with the current position information. The management control unit203accumulates the reception signal intensity transmitted from the vehicle100and the position information thereof, and updates the null point corresponding to the vehicle arrangement information. This corresponds to the case where the null point changes depending on the arrangement of the other parked vehicles100-bto100-d. Thus, the database of the null point storage unit202of the control center200is updated, and the relationship between the vehicle arrangement information and the null point is learned to determine the null point.

FIGS. 4 and 5are flowcharts illustrating operations at the time of entry and exit of the vehicle100. These flowcharts illustrate processing operations of the automatic driving control unit103, the null point determination unit107, and the like of the vehicle100. Incidentally, programs illustrated in these flowcharts may be realized by execution using a computer that includes a CPU, a memory, and the like. Further, these programs may be supplied as various forms of computer-readable computer program products such as a recording medium and a data signal (carrier wave).

A driver and a passenger stop the vehicle100near the carriage porch303and get off. Then, in Step401ofFIG. 4, the driver instructs the control center200to start automated valet parking using a mobile phone or the like.

In Step402, the vehicle100receives a parking position, a detailed map of a parking facility, and a null point from the control center200.

In Step403, the vehicle100stands by until a start instruction is received from the control center200. When the start instruction is received, the process proceeds to Step404.

In Step404, the vehicle100generates the travel route310based on the parking position and the detailed map of the parking facility, and starts traveling along the travel route310.

In Step405, the vehicle100controls the various actuators102based on information from the various external-environment sensors101and travels along the travel route310by automatic driving. Then, the current position information and the reception signal intensity (RSSI) are sequentially transmitted to the control center200.

In Step405, when the vehicle100detects an obstacle using the various external-environment sensors101, a processing operation illustrated inFIG. 5, which will be described later, is performed.

In Step406, it is determined whether the vehicle100has reached a site before the parking position. If the vehicle100has not reached the site before the parking position, it is determined in Step407whether the vehicle100has received a stop instruction from the control center200. This stop instruction is appropriately transmitted from the control center200in order for operation management in the parking facility. If the stop instruction has not been received, the process returns to Step405, and the vehicle100moves along the travel route310in the parking facility while repeating the processing up to Step407.

If the vehicle100has received the stop instruction from the control center200in Step407, the process proceeds to Step408. In Step408, it is determined whether the current position of the vehicle100is the null point. Specifically, it is determined whether the current position indicated by the host vehicle position estimation unit104corresponds to the null point received from the control center200and stored in the null point determination unit107. If the current position is not the null point, the process proceeds to Step409and the vehicle100stops at the current position, that is, the stopping position. Then, the process returns to Step403and the vehicle100stands by until receiving a start instruction from the control center200.

If it is determined in Step408that the current position of the vehicle100is the null point, the process proceeds to Step410. In Step410, the vehicle100moves at the slowest speed to an area where the reception signal intensity becomes equal to or greater than the threshold while confirming the reception signal intensity detected by the RSSI detection unit115. That is, the vehicle100moves forward or backward until escaping the null point. As a result, it is possible to avoid a situation where the vehicle100stops at the null point, it becomes difficult to perform the wireless communication thereafter, and the vehicle100stays on the travel route310.

When the vehicle100has escaped the null point, the process proceeds to Step411. In Step411, the vehicle100stops and transmits information indicating the stopping position to the control center200. Then, the process returns to Step403and the vehicle100stands by until receiving a start instruction from the control center200.

If it is determined in Step406that the vehicle100has reached the site before the parking position, the process proceeds to Step412. In Step412, the vehicle100parks at the parking position by automatic driving, and detects whether the reception signal intensity at this parking position is less than the threshold. If the reception signal intensity is less than the threshold, the process proceeds to Step413. In Step413, the vehicle100exits the parking position and moves until the vehicle100has escaped the null point. Then, the vehicle100moves, at the slowest speed, to the area where the reception signal intensity is equal to or greater than the threshold and stops, and transmits a parking position change request to the control center200. As a result, it is possible to avoid a situation where the vehicle100is parked at the null point, it is difficult to perform the wireless communication thereafter, and it becomes difficult to cause the vehicle100to exit the parking spot.

After the process of Step413, the vehicle100returns to the process of Step402and receives information such as a new parking position from the control center200.

When the vehicle100is parked at the parking position by automatic driving and the reception signal intensity is equal to or greater than the threshold in Step412, the process proceeds to Step414. In Step414, the vehicle100transmits the parking position information and the reception signal intensity to the control center200. In the subsequent Step415, the vehicle100stops a power source such as the engine.

FIG. 5is a flowchart illustrating an operation of the vehicle when detecting an obstacle.FIG. 4illustrates a detailed processing operation when the obstacle is detected on the travel route310in the parking facility in the processing illustrated in Step405ofFIG. 4.

When the vehicle100detects an obstacle by the various external-environment sensors101during the traveling along the travel route310and the obstacle is removed, the various external-environment sensors101recognize that the obstacle has disappeared, and the traveling is started again. However, if the obstacle is not removed even after a lapse of a certain period of time, the processing operation illustrated inFIG. 5is started. Incidentally, this corresponds to a case where a road cone or the like is placed on the travel route310intentionally or unintentionally, for example, as such an obstacle.

If the obstacle is not removed even after the lapse of the certain period of time, it is determined whether the stopping position of the vehicle100is the null point in Step415inFIG. 5. Specifically, it is determined whether the current position indicated by the host vehicle position estimation unit104corresponds to the null point received from the control center200and stored in the null point determination unit107. If the stopping position is the null point, the process proceeds to Step425, and the vehicle100gradually moves forward or backward to a position where the obstacle can be avoided independently of a command from the control center200.

In the subsequent Step435, the vehicle100confirms the reception signal intensity using the RSSI detection unit115to determine whether the vehicle100has moved to the area where the reception signal intensity is equal to or greater than the threshold, that is, whether the vehicle100has escaped the null point. If the vehicle100has not escaped the null point, the process returns to Step425, and the vehicle100gradually moves to a position where the obstacle can be avoided.

If it is determined in Step435that the vehicle100has escaped the null point, the process proceeds to Step445, and the vehicle100stops in Step445. As a result, it is possible to avoid a situation where the vehicle100stops at the null point, it becomes difficult to perform the wireless communication thereafter, and the vehicle100stays on the travel route.

Then, the vehicle100notifies the control center200of that movement is not possible due to the obstacle in the subsequent Step455. Incidentally, the control center200having received the notification takes measures such as dispatching a staff and re-searching a travel route that avoids the obstacle.

Incidentally,FIGS. 4 and 5illustrate the operation at the time of entry of the vehicle100, the same operation is performed even at the time of exit of the vehicle100. That is, at the time of exit, the vehicle100is caused to automatically travel from a parking position to a carriage porch position. In this case, control is performed such that the vehicle100moves until escaping the null point by the same processing as described in Steps401to411ofFIG. 4and Steps415to455ofFIG. 5.

According to the present embodiment, when there is the stop instruction from the control center or the obstacle is present on the route during the automated valet parking, the vehicle does not stop near the null point, and thus, it is possible to reliably receive a subsequent start instruction from the control center, and the vehicle can be prevented from staying on the travel route in the parking facility.

According to the above-described embodiment, the following operational effects are obtained.

(1) The vehicle control device includes: the wireless communication unit105that acquires the null point indicating the position at which wireless communication is poor in the parking facility301and the instruction information for controlling the vehicle100in the parking facility301from the control center200by means of wireless communication; and the automatic driving control unit103that moves the vehicle100until the vehicle100has escaped the null point and then stops the vehicle100when the instruction information acquired by the wireless communication unit105is the instruction for stopping the vehicle100and the instructed stopping position is the null point. As a result, it is possible to prevent the vehicle100from stopping at the null point even when the parking facility301is not spacious.

(2) The vehicle control device includes the null point determination unit107that determines the escaping the null point based on whether the reception signal intensity received from the control center200is equal to or greater than the threshold.

As a result, it is possible to detect that the vehicle100has escaped the null point and to avoid the stop of the vehicle100at the null point.

(3) The automatic driving control unit103changes the parking position to a new parking position when the instruction information acquired by the wireless communication unit105is the instruction to park the vehicle100and the parking position is the position less than the reception signal intensity. As a result, it is possible to avoid the parking of the vehicle100at the null point.

(4) The vehicle control device further includes the various external-environment sensors101that detect an obstacle of the vehicle, and the automatic driving control unit103moves the vehicle100until the vehicle100has escaped the null point while avoiding the obstacle and then stops the vehicle100when the obstacle does not move after the various external-environment sensors101detect the obstacle and the vehicle100stops at the null point. As a result, it is possible to prevent the vehicle100from stopping at the null point even when the obstacle is present.

(5) An automatic parking system includes the vehicle100and the control center200that performs wireless communication with the vehicle100. The vehicle100detects the reception signal intensity received from the control center200and transmits the reception signal intensity to the control center200. The control center200accumulates the reception signal intensity and the arrangement information of the vehicles parked in the parking facility301, and stores the null point determined based on the reception signal intensity and the arrangement information of the parked vehicles in the null point storage unit202. As a result, the control center200can update the null point according to the reception signal intensity and the arrangement information of the parked vehicles.

The present invention is not limited to the above-described embodiments, and other modes, which are conceivable inside a scope of a technical idea of the present invention, are also included in a scope of the present invention as long as characteristics of the present invention are not impaired.

REFERENCE SIGNS LIST