Parking assistance system, vehicle, and guidance device

Abstract

To reduce the number of components and save time and efforts for initialization.SOLUTION: A parking support system which guides a vehicle to a predetermined parking area in a parking lot comprises: a transmitter that transmits ultrasonic sound for sensing the position of a vehicle with respect to the parking area; two receivers that receive ultrasonic sound at two different places with respect to a width direction of the parking area; and an identifying part that identifies the position in the width direction of the vehicle with respect to the parking area on the basis of lag of times when the receivers respectively receive the ultrasonic sound, and the parking support system notifies a driver in the vehicle or the vehicle of information about the position identified by the identifying part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a parking assistance system, a vehicle, and a guidance device. [Background technology]

[0002] Patent document 1 discloses a location detection system equipped with three transducers installed in a parking lot and one receiver installed in a vehicle, which determines the vehicle's location by receiving ultrasonic waves emitted from the three transducers in the parking lot with the single receiver in the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-196928 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the configuration described in Patent Document 1 requires a total of four position sensors, three in the parking lot and one in the vehicle, resulting in a large number of sensors. Also, the configuration described in Patent Document 1 requires the vehicle to store the position data of the wave transmitter in the parking lot in a memory unit and to register the position of the wave transmitter in advance, i.e., to perform initial settings. This results in an increase in the number of sensors, which increases costs, and also requires the effort of initial settings to register the position data of the wave transmitter.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a parking assistance system, a vehicle, and a guidance device that can reduce the number of parts and eliminate the need for initial setup. [Means for solving the problem]

[0006] The parking assistance system of the present invention is a parking assistance system that guides a vehicle to a specified parking area in a parking lot, and is characterized in that it comprises a transmitter that emits ultrasonic waves to detect the position of the vehicle relative to the parking area, two receivers that receive the ultrasonic waves at two different locations in the width direction of the parking area, an identification unit that identifies the width direction position of the vehicle relative to the parking area based on the time difference between when the ultrasonic waves are received by each receiver, and an information providing unit that conveys the position information identified by the identification unit to the driver of the vehicle or the vehicle.

[0007] According to this configuration, the number of sensors in the parking assistance system can be reduced to three in total, reducing the number of parts. Also, initial settings for registering the sensor position data in advance are not required, and the vehicle position relative to the parking area can be identified.

[0008] The vehicle may further include a control unit that is provided in the vehicle and that determines whether the vehicle is located at a predetermined longitudinal position in the parking area and controls the vehicle, and the control unit may determine that parking in the parking area is complete when the position information indicates that the vehicle is located in the width center of the parking area and when it is determined that the vehicle is located at the predetermined longitudinal position.

[0009] With this configuration, the vehicle can determine its widthwise and front-rearward positions relative to the parking area, and can determine that it is located within a predetermined range in the parking lot, and that parking is complete when the conditions are met.

[0010] In addition, when the position information indicates that the vehicle is located at a position shifted from the widthwise center of the parking area and when it is determined that the vehicle is located at the specified longitudinal position, the control unit may notify the driver that the vehicle needs to turn around.

[0011] According to this configuration, it is possible to notify the driver that the vehicle is in a position deviated from the predetermined position, and to urge the driver to correct the position to an appropriate position.

[0012] The parking lot may further include a regulating unit installed in the parking area and regulating the vehicle's forward / backward movement relative to the parking area, and the control unit may determine that the vehicle is located at the specified forward / backward position when it detects that the regulating unit has restricted the forward / backward movement of the vehicle.

[0013] According to this configuration, when the forward / rearward movement of the vehicle is restricted by the restricting unit installed in the parking lot, the vehicle can determine that it is located at a predetermined forward / rearward position within the parking area.

[0014] In addition, the transmitter may be provided on the vehicle and positioned at a central position in the width direction of the vehicle, the two receivers, the identification unit and the information providing unit may be provided on ground equipment installed in the parking lot, the two receivers may be positioned symmetrically on the left and right sides with respect to the center in the width direction of the parking area, and the information providing unit may notify the vehicle of the location information via wireless communication with the vehicle.

[0015] This configuration uses a total of three sensors, consisting of a transmitter on the vehicle side and two receivers on the ground facility side, and can notify the vehicle of its widthwise position relative to the parking area, which is determined by the ground facility side.

[0016] In addition, the transmitter may be provided on ground equipment installed in the parking lot and positioned at the center of the width of the parking area, the two receivers, the identification unit and the information providing unit may be provided on the vehicle, the two receivers may be positioned symmetrically on the left and right sides of the center of the width of the vehicle, and the information providing unit may notify the driver of the location information identified by the identification unit.

[0017] This configuration uses a total of three sensors, consisting of a transmitter on the ground facility side and two receivers on the vehicle side. The vehicle side can then identify the vehicle's widthwise position relative to the parking area and notify the driver of that position information.

[0018] In addition, the ground equipment may further include a charging device that supplies power to the vehicle, the vehicle being a vehicle that can be charged with power supplied from the charging device, and the parking area being an area in which the vehicle can be charged with power from the charging device.

[0019] According to this configuration, when the vehicle is parked for external charging, the vehicle can be guided to a predetermined area where charging is possible.

[0020] The vehicle of the present invention is a vehicle equipped with a parking assistance device for parking in a specified parking area in a parking lot, and the parking assistance device is characterized in that it comprises: a transmitter that emits ultrasonic waves to detect the position of the vehicle relative to the parking area, one of two receivers that receive the ultrasonic waves at two different locations in the width direction of the parking area, and an alarm unit that notifies the driver of the vehicle of position information indicating the width direction position of the vehicle relative to the parking area, which is identified based on the time difference between when the ultrasonic waves are received by each receiver.

[0021] According to this configuration, when detecting the position of the vehicle relative to the parking area, the number of sensors can be reduced to three in total, which reduces the number of parts. Also, the position data of the sensors is not required to be registered in advance, and the position of the vehicle relative to the parking area can be identified.

[0022] The parking area may further include a control unit that determines whether the vehicle is located at a predetermined longitudinal position in the parking area and controls the vehicle, and the control unit may determine that parking in the parking area is complete when the position information indicates that the vehicle is located in the width center of the parking area and when it is determined that the vehicle is located at the predetermined longitudinal position.

[0023] According to this configuration, the vehicle's control unit can determine the widthwise and front-rearward positions of the vehicle relative to the parking area, so that the vehicle can determine that it is located within a predetermined range in the parking lot, and that parking is complete when the conditions are met.

[0024] In addition, when the control unit determines that the vehicle is located at a position shifted from the widthwise center of the parking area and that the vehicle is located at the specified longitudinal position, the control unit may cause the notification unit to notify that the vehicle needs to turn around.

[0025] According to this configuration, it is possible to notify the driver that the vehicle is in a position deviated from the predetermined position, and to urge the driver to correct the position to an appropriate position.

[0026] In addition, the control unit may determine whether the forward / backward movement of the vehicle has been restricted by a regulating unit installed in the parking lot, and if it determines that the forward / backward movement of the vehicle has been restricted by the regulating unit, it may determine that the vehicle is located at the specified forward / backward position.

[0027] According to this configuration, when the forward / rearward movement of the vehicle is restricted by the restricting unit installed in the parking lot, the vehicle can determine that it is located at a predetermined forward / rearward position within the parking area.

[0028] The parking assistance device may further include the transmitter, and the transmitter may be disposed at a central position in a width direction of the vehicle.

[0029] According to this configuration, the vehicle can be configured to include the transmitter.

[0030] The parking assistance device may further include the two receivers, and the two receivers may be disposed at positions symmetrical to the left and right with respect to a center in a width direction of the vehicle.

[0031] This configuration allows the vehicle to be equipped with two receivers.

[0032] The vehicle may further include a battery capable of being charged with power supplied from a charging device installed in the parking lot, and the parking area may be an area in which the battery can be charged with power from the charging device.

[0033] This configuration makes it possible to guide the vehicle to an area where external charging is possible.

[0034] The guidance device of the present invention is a guidance device that is installed in a parking lot and guides a vehicle to a specified parking area in the parking lot, and is characterized in that it comprises two receivers that receive ultrasonic waves emitted from the vehicle at two different locations in the width direction of the parking area, an identification unit that identifies the width direction position of the vehicle relative to the parking area based on the time difference between when the ultrasonic waves are received at each receiver, and a notification unit that notifies the vehicle of the position information identified by the identification unit.

[0035] According to this configuration, when guiding a vehicle to a parking area, the number of sensors can be reduced to three in total, reducing the number of parts. Also, initial settings for registering the sensor position data in advance are not required, and the position of the vehicle relative to the parking area can be identified.

[0036] The parking area may further include a charging device that supplies power to the vehicle, and the parking area may be an area in which the vehicle can be charged with power from the charging device.

[0037] This configuration makes it possible to guide the vehicle to an area where external charging is possible. Effect of the Invention

[0038] In the present invention, the widthwise position of the vehicle relative to the parking area can be identified by one transmitter and two receivers, which reduces the number of parts and eliminates the need for initial setup. [Brief description of the drawings]

[0039] [Figure 1] FIG. 1 is a diagram illustrating a parking assistance system according to an embodiment. [Diagram 2] FIG. 2 is a diagram for explaining the arrangement in the width direction of the parking assistance system. [Diagram 3] FIG. 3 is a block diagram showing the configuration of a vehicle and a charging device. [Figure 4] FIG. 4 is a flow chart showing the control on the charging device side. [Diagram 5] FIG. 5 is a map diagram showing the relationship between the vehicle position and the difference in reception time. [Figure 6] FIG. 6 is a flow chart showing the control on the vehicle side. [Figure 7] FIG. 7 is a diagram showing another method of determining the front and rear stopping positions. [Figure 8] FIG. 8 is a diagram showing still another method of determining the front and rear stopping positions. [Figure 9] FIG. 9 is a diagram illustrating a parking assistance system according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Hereinafter, a parking assistance system, a vehicle, and a guiding device according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiment described below.

[0041] FIG. 1 is a diagram illustrating a parking assistance system according to an embodiment. The parking assistance system 1 includes a vehicle 2 and a charging device 3, and is a system that guides the vehicle 2 to a predetermined parking area 101 in a parking lot 100. The vehicle 2 is an electric vehicle that can be charged with power supplied from an external power source. The charging device 3 is a ground facility installed in the parking lot 100, and is a charging facility that can supply power to the vehicle 2. The charging device 3 may be of either a contact type or a non-contact type. For example, the charging device 3 is configured by a charging stand that allows contact charging, a power transmission device that allows non-contact charging, or the like.

[0042] The parking assistance system 1 detects the widthwise position of the vehicle 2 relative to the parking area 101 using a sonar transmitter 4 installed in the vehicle 2 and a sonar receiver 5 installed in the charging device 3. The sonar transmitter 4 emits ultrasonic waves A. The speed at which the ultrasonic waves A travel is the speed of sound, which can be expressed as 0.34 mm / microsecond. The sonar receiver 5 receives the ultrasonic waves A emitted from the sonar transmitter 4.

[0043] As shown in FIG. 1, one sonar transmitter 4 is provided in the vehicle 2, and two sonar receivers 5 are provided in the charging device 3. As shown in FIG. 2, the sonar receiver 5 is disposed at a symmetrical position with respect to the center line B in the width direction of the parking area 101. That is, the charging device 3 has two sonar receivers 5 disposed at symmetrical positions with respect to the center of the width direction of the parking area 101. The sonar receiver 5 includes a first receiver 5A and a second receiver 5B. As shown in FIG. 2, the first receiver 5A is a sonar receiver 5 disposed on one side with respect to the center line B. As shown in FIG. 2, the second receiver 5B is a sonar receiver 5 disposed on the other side with respect to the center line B. In contrast, one sonar transmitter 4 is disposed at the center position in the width direction of the vehicle 2. When the width direction position of the vehicle 2 is located at the center of the width direction of the parking area 101, the sonar transmitter 4 is located on the center line B as shown in FIG. 2.

[0044] In addition, in the longitudinal direction of the vehicle 2, the sonar transmitter 4 is disposed on the rear side of the vehicle 2. Similarly, in the longitudinal direction of the parking area 101, the sonar receiver 5 is disposed on the rear side of the parking area 101 or at a position rearward of the parking area 101. And, as shown in Fig. 2, the first receiver 5A and the second receiver 5B are disposed at positions facing the rear of the vehicle 2 positioned in the parking area 101. For example, two sonar receivers 5 are disposed at a position rearward of a wheel stopper 102 installed in the parking lot 100.

[0045] In the parking assistance system 1, the widthwise position of the vehicle 2 relative to the parking area 101 is detected based on the time difference between when the ultrasonic waves A are received by the two sonar receivers 5. Then, the charging device 3 notifies the vehicle 2 of the detected position information of the vehicle 2. The vehicle 2 can notify the driver of the position information. This makes it possible to provide the driver of the vehicle 2 with information for guiding the vehicle 2 to a specified area of ​​the parking lot 100.

[0046] FIG. 3 is a block diagram showing the configuration of a vehicle and a charging device.

[0047] The vehicle 2 includes a sonar transmitter 4 , a communication unit 21 , a control unit 22 , a power receiving unit 23 , a notification unit 24 , and a vehicle speed sensor 25 .

[0048] The sonar transmitter 4 emits ultrasonic waves A for detecting the widthwise position of the vehicle 2 relative to the parking area 101. Since this sonar transmitter 4 is disposed on the rear side of the vehicle 2, it emits ultrasonic waves A toward the rear of the vehicle 2 when the vehicle 2 reverses to park in the parking area 101. In this description, the sonar transmitter may be simply referred to as a transmitter or a sensor.

[0049] The communication unit 21 communicates with an external device. The communication unit 21 is capable of wireless communication with the charging device 3. That is, the communication unit 21 transmits a signal from the vehicle 2 to the charging device 3 and receives a signal from the charging device 3. For example, the communication unit 21 is capable of transmitting and receiving a signal to and from a device on the ground through wireless communication such as Wi-Fi (registered trademark).

[0050] The control unit 22 is an electronic control device that controls the vehicle 2. This electronic control device is configured to include a microcomputer equipped with a CPU, RAM, ROM, and an input / output interface. Therefore, the control unit 22 performs signal processing according to a program pre-stored in the ROM. In addition, signals from various sensors are input to the control unit 22. For example, a signal from a vehicle speed sensor 25 that detects the vehicle speed of the vehicle 2 is input to the control unit 22. Then, the control unit 22 executes control based on the signals input from the various sensors.

[0051] The power receiving unit 23 receives power supplied from an external power source. The vehicle 2 is equipped with a battery that can be charged with power supplied from a charging device 3 provided in the parking lot 100. The power received by the power receiving unit 23 is charged into a battery mounted on the vehicle 2. In the case of non-contact power supply, the power receiving unit 23 is configured to include a power receiving coil. In the case of contact power supply, the power receiving unit 23 is configured to include a charging port. The power receiving unit 23 is controlled by the control unit 22.

[0052] The notification unit 24 notifies the driver of the vehicle 2 of information. The notification unit 24 is configured, for example, by a car navigation device. Therefore, the notification unit 24 can notify the driver of various information by screen display or audio output. The notification unit 24 is controlled by the control unit 22.

[0053] In the vehicle 2 configured as above, the control unit 22 functions as a parking assistance device. The parking assistance device provided in the vehicle 2 includes a sonar transmitter 4, a communication unit 21, the control unit 22, and an alarm unit 24. For example, when the vehicle 2 receives a guidance request from a higher-level system or the driver, the control unit 22 starts parking assistance control. In this case, the control unit 22 activates the sonar transmitter 4 and causes the sonar transmitter 4 to emit ultrasonic waves A toward the rear of the vehicle 2. Then, the control unit 22 causes the alarm unit 24 to notify the driver of the location information notified to the vehicle 2 from the charging device 3. In other words, the control unit 22 functions as an information providing unit that conveys the location information to the driver of the vehicle 2.

[0054] The charging device 3 includes a sonar receiver 5 , a communication unit 31 , a control unit 32 , and a power supply unit 33 .

[0055] The sonar receiver 5 receives the ultrasonic waves A from the sonar transmitter 4. The sonar receiver 5 is a receiver that detects the difference in reception time of the ultrasonic waves A at two different locations in the width direction. Since the sonar receiver 5 is disposed at a rear position of the parking area 101, it is able to receive the ultrasonic waves A emitted from the sonar transmitter 4 toward the rear of the vehicle 2 when the vehicle 2 is parked in the parking area 101. In this description, the sonar receiver may be simply referred to as a receiver or a sensor.

[0056] The communication unit 31 communicates with an external device. The communication unit 31 is capable of wireless communication with the vehicle 2. That is, the communication unit 31 transmits a signal from the charging device 3 to the vehicle 2 and receives a signal from the vehicle 2.

[0057] The control unit 32 is an electronic control device that controls the charging device 3. This electronic control device is configured to include a microcomputer equipped with a CPU, RAM, ROM, and an input / output interface. Therefore, the control unit 32 performs signal processing according to a program pre-stored in the ROM. In addition, signals from various sensors are input to the control unit 32. Then, the control unit 32 executes control based on the signals input from the various sensors.

[0058] The power supply unit 33 supplies power to the vehicle 2. In the case of non-contact power supply, the power supply unit 33 includes a power transmission coil. In the case of contact power supply, the power supply unit 33 includes a charging cable. The power supply unit 33 is controlled by the control unit 32.

[0059] The charging device 3 configured in this manner functions as a guidance device that guides the vehicle 2 in the parking lot 100 to the parking area 101. The widthwise position of the vehicle 2 relative to the parking area 101 is detected based on the difference in time when ultrasonic waves A are received by the two sonar receivers 5 provided in the charging device 3. Then, the control unit 32 of the charging device 3 notifies the vehicle 2 of the position information. In other words, the control unit 32 functions as an identifying unit that identifies the position of the vehicle 2, and also functions as a notifying unit that notifies the vehicle 2 of the position information. In other words, the control unit 32 functions as an information providing unit that transmits the identified position information to the vehicle 2.

[0060] Fig. 4 is a flow chart showing control on the charging device side. The charging device 3 starts the control shown in Fig. 4 when a start command is received from the vehicle 2. The control shown in Fig. 4 is repeatedly performed by the charging device 3.

[0061] The charging device 3 receives ultrasonic waves A at two different positions in the width direction by the sonar receiver 5 (step S101). In step S101, the ultrasonic waves A are received by the first receiver 5A and the second receiver 5B. The two receivers receive the ultrasonic waves A emitted from the vehicle at their respective timings. At that time, the charging device 3 acquires information on the time when the ultrasonic waves A are received by each receiver. In this case, the time when the first receiver 5A receives the ultrasonic waves A is defined as the first reception time t1, and the time when the second receiver 5B receives the ultrasonic waves A is defined as the second reception time t2. The first reception time t1 and the second reception time t2 can be detected, for example, from a clock signal of the control unit 32, i.e., the elapsed time from startup.

[0062] The charging device 3 also calculates the difference Δt between the reception times when the ultrasonic wave A is received at the two locations by the sonar receiver 5 (step S102). In step S102, the control unit 32 performs a calculation process to calculate the difference Δt (=t1-t2) between the reception times by subtracting the second reception time t2 at the second receiver 5B from the first reception time t1 at the first receiver 5A.

[0063] Then, the charging device 3 determines whether or not the difference Δt in reception time is smaller than the front determination threshold (step S103). In step S103, it is determined whether or not the absolute value of the difference Δt in reception time is smaller than the front determination threshold.

[0064] The frontal determination threshold is a preset threshold, and is set to a time that matches the left-right accuracy (horizontal axis) at the front-rear position (vertical axis) to be guided as shown in Fig. 5. For example, the frontal determination threshold is set to several microseconds. By using this frontal determination threshold, the width direction position of the vehicle 2 relative to the charging device 3 can be determined.

[0065] In the example shown in FIG. 5, when the position in the vertical axis direction (front-rear position) is 400 mm and it is desired to guide the vehicle to within ±10 mm to the left and right, the front determination threshold is set to 6 μs. The front determination threshold is represented by a hyperbola L1. The hyperbola indicates that the time difference is constant. Therefore, when the difference in reception time Δt is smaller than the front determination threshold, it can be determined that the position of the sonar transmitter 4 is included in the front area. Moreover, the hyperbola L2 indicates the case where the time difference is 12 μs, and the hyperbola L3 indicates the case where the time difference is 30 μs.

[0066] Returning to the explanation of Fig. 4, if the difference Δt in reception times is smaller than the front determination threshold (step S103: Yes), the charging device 3 determines that the vehicle 2 is in front of the charging device 3, and notifies the vehicle 2 that the width direction position of the vehicle 2 with respect to the parking area 101 is the front (step S104). In step S104, the control unit 32 generates a notification signal indicating that the vehicle position is the front, and the notification signal is transmitted from the communication unit 31. After the process of step S104 is performed, this control routine ends.

[0067] If the difference Δt in the reception times is equal to or greater than the front determination threshold (step S103: No), the charging device 3 determines that the vehicle 2 is not in front of the charging device 3, and determines whether the first reception time t1 is greater than the second reception time t (step S105). In step S105, it is determined whether the vehicle 2 is shifted to the left or right of the center of the width direction of the parking area 101. The sonar receiver 5 faces the front of the parking area 101, the first receiver 5A is located on the left side of the center line B, and the second receiver 5B is located on the right side of the center line B. Therefore, when the sonar transmitter 4 is located to the right of the center line B in the width direction of the parking area 101, the distance between the sonar transmitter 4 and the first receiver 5A is longer than the distance between the sonar transmitter 4 and the second receiver 5B. In this case, the first reception time t1 is greater than the second reception time t2.

[0068] If the first reception time t1 is greater than the second reception time t2 (step S105: Yes), the charging device 3 determines that the first receiver 5A on the left side is farther from the vehicle 2 than the second receiver 5B on the right side, and notifies the vehicle 2 that the width direction position of the vehicle 2 relative to the parking area 101 is shifted to the right (step S106). In step S106, the control unit 32 generates a notification signal indicating that the vehicle position is shifted to the right, and the notification signal is transmitted from the communication unit 31. After the process of step S106 is performed, this control routine ends.

[0069] If the first reception time t1 is equal to or shorter than the second reception time t2 (step S105: No), the charging device 3 determines that the second receiver 5B on the right side is farther from the vehicle 2 than the first receiver 5A on the left side, and notifies the vehicle 2 that the width direction position of the vehicle 2 relative to the parking area 101 is shifted to the left (step S107). In step S107, the control unit 32 generates a notification signal indicating that the vehicle position is shifted to the left, and the notification signal is transmitted from the communication unit 31. After the process of step S107 is performed, this control routine ends.

[0070] 6 is a flow chart showing the control on the vehicle side. The control shown in FIG.

[0071] The vehicle 2 outputs a start command to the guidance system (step S201). The guidance system includes a parking assistance device on the vehicle side and a guidance device on the charging device side. The control unit 22 issues a start command to the charging device side and the sonar transmitter 4 on the vehicle side using wireless communication. In step S201, a start command is sent from the communication unit 21 of the vehicle 2 to the charging device 3, and the control unit 22 starts up the sonar transmitter 4 to cause the sonar transmitter 4 to emit ultrasonic waves A.

[0072] The control unit 22 of the vehicle 2 checks the determination result on the charging device side (step S202). In step S202, the determination result notified from the charging device 3 is received. This determination result includes any one of the following: front, right shift, or left shift.

[0073] The control unit 22 determines whether or not the received determination result indicates that the vehicle position is in front (step S203). In step S203, it is determined whether or not a notification indicating that the vehicle position is in front has been received.

[0074] If it is determined that the received determination result indicates that the vehicle position is ahead (step S203: Yes), the vehicle 2 notifies the driver of information instructing the vehicle 2 to continue going straight (step S204). In step S204, the control unit 22 controls the notification unit 24 to notify information of going straight from the notification unit 24. For example, if the notification unit 24 is configured with a car navigation device, the control unit 22 causes the notification unit 24 to display "go straight".

[0075] After performing the process of step S204, the control unit 22 determines whether or not the wheels of the vehicle 2 have come into contact with the wheel chocks 102 (step S205). In step S205, it is determined whether or not the wheels of the vehicle 2 have come into contact with the wheel chocks 102 based on a signal from the vehicle speed sensor 25. The control unit 22 can determine whether or not the wheels of the vehicle 2 have come into contact with the wheel chocks 102 based on a sudden decrease in vehicle speed. If the wheels of the vehicle 2 have come into contact with the wheel chocks 102, it can be determined that the vehicle 2 is located at a predetermined longitudinal position in the parking area 101.

[0076] If it is determined that the wheels of the vehicle 2 are not in contact with the wheel chocks 102 (step S205: No), this control routine returns to step S202.

[0077] If it is determined that the wheels of the vehicle 2 have contacted the wheel chocks 102 (step S205: Yes), the vehicle 2 notifies the driver that parking has been completed (step S206). In step S206, the control unit 22 controls the notification unit 24 to notify information that parking has been completed from the notification unit 24. For example, if the notification unit 24 is a car navigation device, the control unit 22 causes the notification unit 24 to display "Parking Completed." Furthermore, in the processing of step S206, the vehicle 2 determines that parking in the parking area 101 has been completed. Furthermore, the vehicle 2 can output a stop command to the guidance system. After the processing of step S206 is performed, this control routine ends.

[0078] In addition, if it is determined in step S203 that the received determination result does not indicate that the vehicle position is forward (step S203: No), the control unit 22 determines whether the determination result indicates that the vehicle position is shifted to the right (step S207). In step S207, it is determined whether a notification indicating that the vehicle position is shifted to the right has been received.

[0079] If it is determined that the received determination result indicates that the vehicle position is shifted to the right (step S207: Yes), the vehicle 2 notifies the driver of information instructing the driver to steer left (step S208). In step S208, the control unit 22 controls the notification unit 24 to notify information of steering left from the notification unit 24. For example, the control unit 22 causes the notification unit 24 to display "steer left."

[0080] On the other hand, if it is determined that the received determination result does not indicate that the vehicle position is shifted to the right (step S207: No), the vehicle 2 notifies the driver of information instructing the driver to steer to the right (step S209). In step S209, the control unit 22 controls the notification unit 24 to notify information about steering to the right from the notification unit 24. For example, the control unit 22 causes the notification unit 24 to display "steer to the right".

[0081] After performing the process of step S208 or step S209, the control unit 22 determines whether or not the wheels of the vehicle 2 have come into contact with the wheel chocks 102 (step S210).

[0082] If it is determined that the wheels of the vehicle 2 are not in contact with the wheel chocks 102 (step S210: No), this control routine returns to step S202.

[0083] If it is determined that the wheels of the vehicle 2 have contacted the wheel chocks 102 (step S210: Yes), the vehicle 2 notifies the driver that a turn is required (step S211). In step S211, the control unit 22 controls the notification unit 24 to notify information indicating that the vehicle 2 needs to turn. For example, the control unit 22 causes the notification unit 24 to display "turn". After the process of step S211 is performed, this control routine ends.

[0084] As described above, according to the embodiment, the parking assistance system 1 consisting of one sonar transmitter 4 and two sonar receivers 5 can notify the vehicle 2 of the width direction position of the vehicle 2 relative to the parking area 101 and notify the driver. This makes it possible to reduce the number of sonar sensors, i.e., the number of parts. Also, since initial settings such as setting the position of the sonar sensor in advance are not required, the effort of setting is eliminated.

[0085] The parking operation of the vehicle 2 is not limited to being performed by the driver, but can be performed by an automatic driving system. That is, if the vehicle 2 is equipped with an automatic driving system, the control shown in FIG. 6 is automatically performed by the vehicle 2. In this case, in the process of step S204, the vehicle 2 automatically moves straight backward. In addition, in the process of step S208, the vehicle 2 automatically steers to the left, correcting the vehicle position so that it approaches the front. Similarly, in the process of step S209, the vehicle 2 automatically steers to the right, correcting the vehicle position so that it approaches the front. Then, in the process of step S211, the vehicle 2 automatically performs a turnaround, and a command is issued to start over again from the beginning.

[0086] The charging device 3 may also be an automatic charging device for charging a driving battery mounted on the vehicle 2.

[0087] Furthermore, the parking assistance system 1 is not limited to being applied to parking lots 100 equipped with charging equipment 3, but can also be applied to parking lots 100 equipped with ground facilities other than the charging equipment 3. In other words, the ground facilities on which the sonar receiver 5 is installed are not limited to the charging equipment 3 such as a charging stand.

[0088] Furthermore, the difference Δt between the reception times may be a value (=t2−t1) calculated by subtracting the first reception time t1 at the first receiver 5A from the second reception time t2 at the second receiver 5B.

[0089] The notification unit 24 is not limited to a car navigation device. For example, the location information can be visually or audibly notified to the passenger of the vehicle 2 via a human machine interface (HMI) provided in the vehicle 2. The HMI is an interface for inputting and outputting information between the passenger and the vehicle 2.

[0090] In addition, the method of detecting the longitudinal position of the vehicle 2 is not limited to the method of detecting the wheels coming into contact with the wheel stopper 102. Therefore, as an alternative to the wheel stopper 102, a clearance sonar can be used. For example, as shown in FIG. 7, the vehicle 2 is equipped with a clearance sonar 6 arranged on the rear side of the vehicle 2. The control unit 22 of the vehicle 2 uses the clearance sonar 6 to identify the longitudinal position of the vehicle 2. In the example shown in FIG. 7, a first clearance sonar 6A and a second clearance sonar 6B are arranged on the rear side of the vehicle 2. In the parking lot 100, an obstacle 103 such as a wall is arranged behind a parking area 101. The clearance sonar 6 transmits a transmission wave C to detect the obstacle 103 located behind the vehicle 2. When the vehicle 2 detects the obstacle 103, parking is completed. Alternatively, parking is completed when the clearance sonar 6 detects the distance to the obstacle 103. Furthermore, the sonar transmitter 4 and the clearance sonar 6 each emit a transmission wave of a different frequency, which makes it possible to avoid interference with the sonar transmitter 4, which is a sonar for detecting left and right.

[0091] As another alternative to the wheel stopper 102, the sonar transmitter 4 on the vehicle side can be changed to a sonar transceiver. For example, as shown in FIG. 8, the vehicle 2 includes a sonar transceiver 7 disposed on the rear side of the vehicle 2. The sonar transceiver 7 is disposed at the center position in the width direction of the vehicle 2. After transmitting ultrasonic waves A for detecting the width direction position, the sonar transceiver 7 receives a reflected wave D of the ultrasonic waves A. The control unit 22 calculates the distance to the obstacle 103 using the time when the sonar transceiver 7 receives the reflected wave D. Furthermore, the control unit 22 detects the distance to the obstacle 103, and determines that parking is complete when the distance reaches a target distance. Note that the vehicle 2 can detect not only the obstacle 103 but also the distance to the charging device 3.

[0092] Moreover, the relationship of transmission and reception can be reversed. That is, the sonar transmitter can be installed on the ground equipment on the parking lot side, and the sonar receiver can be installed on the vehicle side. For example, as shown in FIG. 9, the charging device 3 includes one sonar transmitter 8. The vehicle 2 includes two sonar receivers 9. The sonar receiver 9 includes a first receiver 9A and a second receiver 9B that are arranged symmetrically with respect to the center of the width direction of the vehicle 2. The parking assistance device included in the vehicle 2 includes two sonar receivers 9, a control unit 22, and an alarm unit 24. The sonar transmitter 8 transmits ultrasonic waves E, and the sonar receiver 9 receives the ultrasonic waves E. The control unit 22 of the vehicle 2 calculates the difference Δt between the time when the first receiver 9A receives the ultrasonic waves E and the time when the second receiver 9B receives the ultrasonic waves E. That is, the vehicle 2 performs the processes of steps S101 to S107 shown in FIG. 5. In this case, in steps S104, S106, and S107, the control unit 22 determines whether the vehicle 2 is facing forward, shifted to the right, or shifted to the left. This allows the vehicle 2 to detect its widthwise position relative to the parking area 101. Furthermore, in steps S104, S106, and S107, the notification unit 24 can display text information indicating the front and both left and right arrows, text information indicating a shift to the right and a rightward arrow, and text information indicating a shift to the left and a leftward arrow. [Explanation of symbols]

[0093] 1. Parking Assistance System 2 Vehicles 3 Charging device 4 Sonar Transmitter 5 Sonar Receiver 5A 1st receiver 5B Second receiver 100 Parking 101 Parking Area 102 Wheel chock

Claims

1. A parking assistance system that guides a vehicle to a predetermined parking area in a parking lot, a transmitter mounted on the vehicle for emitting ultrasonic waves to detect the position of the vehicle relative to the parking area; Two receivers are provided in ground equipment installed in the parking lot, and receive the ultrasonic waves at two different locations in the width direction of the parking area; an identification unit that is provided in the ground facility and identifies a width direction position of the vehicle relative to the parking area based on a time difference when the ultrasonic waves are received by each receiver; an information providing unit that is provided in the ground facility and that notifies the vehicle of the location information identified by the identifying unit through wireless communication with the vehicle; A notification unit provided in the vehicle and configured to notify a driver of the vehicle of the location information; A control unit is provided in the vehicle and determines whether the vehicle is located at a predetermined longitudinal position in the parking area and controls the vehicle. Equipped with the one transmitter is disposed on the rear side of the vehicle in the front-rear direction of the vehicle and at a central position in the width direction of the vehicle, The two receivers are disposed at a rear side of the parking area or at a rear side of the parking area in the front-rear direction of the parking area, and at positions symmetrical with respect to a center in a width direction of the parking area, and are disposed at a position facing a rear surface of the vehicle located in the parking area, When the position information indicates that the vehicle is located at the center of the parking area in the width direction and when the control unit determines that the vehicle is located at the predetermined longitudinal position, the control unit determines that parking in the parking area is completed and causes the notification unit to notify that parking has been completed. A parking assistance system comprising:

2. When the position information indicates that the vehicle is located at a position shifted from the center in the width direction of the parking area and when the control unit determines that the vehicle is located at the predetermined longitudinal position, the control unit controls the notification unit to notify that the vehicle needs to turn around.

2. The parking assistance system according to claim 1 .

3. A restriction unit is further provided in the parking lot to restrict the vehicle from moving forward and backward relative to the parking area. The control unit determines that the vehicle is located at the predetermined position in the longitudinal direction when detecting that the movement of the vehicle in the longitudinal direction has been restricted by the restricting unit.

3. The parking assistance system according to claim 1, wherein the vehicle is driven in a direction parallel to the vehicle axis.

4. A parking assistance system that guides a vehicle to a predetermined parking area in a parking lot, A transmitter provided in a ground facility installed in the parking lot, which transmits ultrasonic waves to detect the position of the vehicle relative to the parking area; Two receivers are provided on the vehicle and receive the ultrasonic waves at two different positions in a width direction of the parking area; an identification unit provided in the vehicle and identifying a width direction position of the vehicle relative to the parking area based on a time difference between when the ultrasonic waves are received by each receiver; a notification unit provided in the vehicle and configured to notify a driver of the vehicle of the location information identified by the identification unit; A control unit provided in the vehicle, which determines whether the vehicle is located at a predetermined longitudinal position in the parking area and controls the vehicle; Equipped with The one transmitter is disposed at a rear side of the parking area or at a rear side of the parking area in the front-rear direction of the parking area, and at a central position in the width direction of the parking area, the two receivers are disposed at positions on the rear side of the vehicle in the front-rear direction of the vehicle and symmetrical with respect to a center in a width direction of the vehicle, When the position information indicates that the vehicle is located at the center of the parking area in the width direction and when the control unit determines that the vehicle is located at the predetermined longitudinal position, the control unit determines that parking in the parking area is completed and causes the notification unit to notify that parking has been completed. A parking assistance system comprising:

5. When the position information indicates that the vehicle is located at a position shifted from the center in the width direction of the parking area and when the control unit determines that the vehicle is located at the predetermined longitudinal position, the control unit notifies the driver that the vehicle needs to turn around.

5. The parking assistance system according to claim 4.

6. A restriction unit is further provided in the parking lot to restrict the vehicle from moving forward and backward relative to the parking area. The control unit determines that the vehicle is located at the predetermined position in the longitudinal direction when detecting that the movement of the vehicle in the longitudinal direction has been restricted by the restricting unit.

6. The parking assistance system according to claim 4 or 5.

7. A vehicle equipped with a parking assistance device for parking in a predetermined parking area in a parking lot, The parking assistance device includes: a transmitter for emitting ultrasonic waves to detect the position of the vehicle relative to the parking area; a notification unit that notifies a driver of the vehicle of position information indicating a width direction position of the vehicle relative to the parking area, the position information being specified based on a time difference between when the ultrasonic waves are received by two receivers that receive the ultrasonic waves at two different positions in the width direction of the parking area; and a control unit that determines whether the vehicle is located at a predetermined longitudinal position in the parking area and controls the vehicle; Equipped with the one transmitter is disposed on the rear side of the vehicle in the front-rear direction of the vehicle and at a central position in the width direction of the vehicle, When the position information indicates that the vehicle is located at the center of the parking area in the width direction and when the control unit determines that the vehicle is located at the predetermined longitudinal position, the control unit determines that parking in the parking area is completed and causes the notification unit to notify that parking has been completed. A vehicle characterized by:

8. When the position information indicates that the vehicle is located at a position shifted from the center in the width direction of the parking area and when the control unit determines that the vehicle is located at the predetermined longitudinal position, the control unit notifies the notification unit that the vehicle needs to turn around.

8. The vehicle according to claim 7.

9. The control unit is determining whether or not the forward / rearward movement of the vehicle in the parking lot has been restricted by a restricting unit installed in the parking lot; When it is determined that the movement of the vehicle in the longitudinal direction is restricted by the restricting unit, it is determined that the vehicle is located at the predetermined longitudinal position.

9. A vehicle as claimed in claim 7 or 8.

10. A vehicle equipped with a parking assistance device for parking in a predetermined parking area in a parking lot, The parking assistance device includes: a transmitter for transmitting ultrasonic waves for detecting the position of the vehicle relative to the parking area, and two receivers for receiving ultrasonic waves at two different positions in a width direction of the parking area, the ultrasonic waves being transmitted from the transmitter; a notification unit that notifies a driver of the vehicle of position information indicating a width direction position of the vehicle with respect to the parking area identified based on a time difference between when the ultrasonic waves are received by each receiver; and a control unit that determines whether the vehicle is located at a predetermined longitudinal position in the parking area and controls the vehicle; Equipped with the two receivers are disposed at positions on the rear side of the vehicle in the front-rear direction of the vehicle and symmetrical with respect to a center in a width direction of the vehicle, When the position information indicates that the vehicle is located at the center of the parking area in the width direction and when the control unit determines that the vehicle is located at the predetermined longitudinal position, the control unit determines that parking in the parking area is completed and causes the notification unit to notify that parking has been completed. A vehicle characterized by:

11. When the position information indicates that the vehicle is located at a position shifted from the center in the width direction of the parking area and when the control unit determines that the vehicle is located at the predetermined longitudinal position, the control unit notifies the notification unit that the vehicle needs to turn around.

11. The vehicle according to claim 10.

12. The control unit is determining whether or not the forward / rearward movement of the vehicle in the parking lot has been restricted by a restricting unit installed in the parking lot; When it is determined that the movement of the vehicle in the longitudinal direction is restricted by the restricting unit, it is determined that the vehicle is located at the predetermined longitudinal position.

12. A vehicle as claimed in claim 10 or 11.

13. A guidance device that is installed in a parking lot and guides a vehicle to a predetermined parking area in the parking lot, two receivers that receive ultrasonic waves transmitted from a single transmitter installed in the vehicle at two different locations in a width direction of the parking area; an identification unit that identifies a width direction position of the vehicle relative to the parking area based on a time difference between when the ultrasonic waves are received by each receiver; a notification unit that notifies the vehicle of the location information identified by the identification unit; A charging device that supplies power to the vehicle; Equipped with The two receivers are disposed at a rear side of the parking area or at a rear side of the parking area in the front-rear direction of the parking area, and at positions symmetrical with respect to a center in a width direction of the parking area, and are disposed at a position facing a rear surface of the vehicle located in the parking area, The parking area is an area in which the vehicle can be charged with power from the charging device. A guidance device characterized by:

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