KR20170061019A - Method of detecting parking lot with rader - Google Patents

Abstract

(A) a plurality of radar transmission signals are sequentially propagated to a parking surface using a radar and a motor connected to the radar, and a method for detecting the presence or absence of a vehicle on a parking surface using the radar described above, And sequentially receiving a plurality of reflected wave signals corresponding thereto; (b) sequentially performing template matching on the plurality of received signals; (c) deriving a template matching maximum value for an arbitrary received signal among the plurality of received signals based on the template matching result, and comparing the template matching maximum value with a predetermined first reference value; And (d) determining whether or not a vehicle exists on the parking surface according to the result of the comparison, wherein the radar rotates at a predetermined angle to the driving paper of the motor, (A) to (d) are repeatedly performed on the parking surface.

Description

Technical Field [0001] The present invention relates to a method of detecting a parking lot using a radar,

More particularly, the present invention relates to a method for detecting a plurality of parking surfaces using a single radar, detecting a position of the radar and a parking surface, A vehicle detection method using an algorithm for correcting a signal error is disclosed.

A parking lot is a place to provide a parking space for a plurality of vehicles in a specific space, and it is possible to park only a limited number of vehicles in a limited space. Therefore, in an area having a large number of moving vehicles, In particular, since there is no way for the driver to know the information about the specific parking lot in advance, the driver of the vehicle can recognize the information even if there is no parking space at the desired destination, so that unnecessary time and fuel consumption . ≪ / RTI >

Accordingly, various studies are being conducted on a parking information providing system in which parking lot information, which is information on a parking lot adjacent to a current position of the vehicle, is provided to a vehicle driver so that a driver of the vehicle recognizes information on an adjacent parking lot in advance.

Accordingly, in order to provide the parking lot information, it is necessary to accurately grasp, in real time, the parking space and the position of the parking space in the current parking lot. This is because it is very necessary to indicate to the driver whether or not the parking lot is full and the number of parking spaces available, and to efficiently manage the parking lot.

In this regard, conventionally, a loop coil system or an ultrasonic system is used to determine whether the vehicle is parked or tolerated in each unit parking space.

The loop coil method is a method of determining the presence or absence of a vehicle by embedding a loop coil under a concrete floor of a unit parking space and then detecting a change in a magnetic field depending on whether the vehicle enters or exits the vehicle. However, such a loop coil method has a disadvantage in that, in the case of an existing parking lot, the concrete is cut, the loop coil is buried, and the surface is re-coated, and the construction is troublesome and the construction cost is very high. Due to these drawbacks, the loop coil method has been a limiting factor in intelligent parking space management.

The ultrasound system, which is another method of determining whether a vehicle is parked, detects the presence of a vehicle by sensing ultrasonic waves reflected from the floor by scanning an ultrasonic wave from the ultrasonic sensor attached to the ceiling of each unit parking space toward the floor. However, the ultrasound of such a system is sensitive to climate and surrounding environment, and it can detect not only vehicles but also other objects or persons, so that the vehicle can not be accurately sensed. Furthermore, when an ultrasonic sensor is attached, a separate structure is required, which complicates the installation and requires a high cost.

Therefore, there is a continuing research on the parking management method using the new parking detection method.

The present invention relates to a method of detecting a parking side vehicle using a radar. More particularly, the present invention relates to a method for detecting a plurality of parking surfaces by a single radar, Discloses a vehicle sensing method using an algorithm that corrects a sensing signal error that may occur depending on the position between the surfaces and the tilted angle of the parked vehicle.

According to an aspect of the present invention, there is provided a method for detecting the presence or absence of a vehicle on a parking surface using a radar, the method comprising the steps of: (a) using a radar and a motor connected to the radar, Sequentially propagating a plurality of radar transmission signals to the plurality of radar transmission signals and sequentially receiving a plurality of reflected wave signals for the plurality of radar transmission signals; (b) sequentially performing template matching on the plurality of received signals; (c) deriving a template matching maximum value for an arbitrary received signal among the plurality of received signals based on the template matching result, and comparing the template matching maximum value with a predetermined first reference value; And (d) determining whether or not a vehicle exists on the parking surface according to the result of the comparison, wherein the radar rotates at a predetermined angle to the driving paper of the motor, (A) to (d) are repeatedly performed on the parking surface.

According to an embodiment of the present invention, the step (a) includes: dividing a region where the radar transmission signal is propagated to the parking surface into n partial regions; And propagating a transmission signal for each of the n partial regions and receiving a reflected wave signal therefrom.

At this time, the n partial areas within the parking surface according to the embodiment of the present invention may be partitioned in a direction toward the other surface facing the one surface with respect to the one surface of the parking surface.

The radar according to an embodiment of the present invention can propagate a radar transmission signal sequentially to the n partial regions while rotating at a first angle in accordance with the motion support of the motor.

In the step (b) according to the embodiment of the present invention, as the radar sequentially propagates a radar transmission signal to the n partial areas while rotating at the first angle, The template matching can be sequentially performed with respect to the received signal.

According to an embodiment of the present invention, the step (c) may compare a template matching value of a received signal in an arbitrary partial area among the n partial areas within the parking plane with the first reference value.

As a result of the comparison, the step (d) according to the embodiment of the present invention determines that an object in the arbitrary partial area is located when the template matching value is larger than the first reference value, The distance between the radar and the object can be derived by analyzing the maximum received signal interval.

If the template matching value is less than or equal to the first reference value as a result of the comparison, the step (d) derives a change amount of the template matching value in the same received signal section for each of the n partial areas step; Comparing a maximum value of the amount of change in the derived template matching value with a predetermined second reference value; And determining whether the vehicle is present according to the comparison result.

In the step (d), a distance between the radar and the object may be determined by analyzing a received signal section in which a maximum value of the derived variation amounts of the template matching values is displayed.

The method of detecting a parking surface according to an embodiment of the present invention includes the steps of rotating the radar at a second angle by driving support of the motor after determining whether the vehicle exists on the parking surface; And repeating the steps (a) to (d) for another parking surface adjacent to the parking surface as the radar rotates at the second angle.

Meanwhile, the template matching value for the received signal according to the embodiment of the present invention may be an operation value according to the position where the received signal is received based on the radar.

The template matching step according to the embodiment of the present invention may use a method of calculating a cross correlation value between the transmission signal and the reception signal.

According to the present invention, a plurality of parking surfaces are detected by a single radar, and an algorithm for correcting a sensing signal error that may occur depending on a position between a radar and a parking surface and a tilted angle of the parked vehicle is used. The accuracy and the system efficiency of the system can be improved.

1 is a diagram showing a schematic configuration diagram of an ultra-wideband radar.
2 is a diagram showing a schematic configuration diagram of a transmitting antenna and a receiving antenna of an UWB radar.
FIG. 3 is a diagram illustrating an example of a signal and a signal sampling process of a transmission signal and a reception signal in an UWB radar.
4 is a schematic flow diagram of a method for performing object detection and distance measurement in an UWB radar.
5 is a schematic block diagram illustrating a system for detecting a plurality of parking surfaces using a radar according to an embodiment of the present invention.
6 is a flowchart illustrating a process of detecting an object using a template matching technique in a radar system according to an embodiment of the present invention.
FIG. 7 is a diagram schematically illustrating calculation of a cross-correlation between two signals. FIG.
FIG. 8 is a diagram schematically illustrating a template matching process to be used by a parking surface sensing system according to an embodiment of the present invention.
9 is a diagram showing an example of a received signal waveform according to whether or not a vehicle is parked on a parking surface, according to an embodiment of the present invention.
10 is a view for explaining an example of a form in which a signal is reflected on an object according to an embodiment of the present invention.
11 is a view for explaining another example of a form in which a signal is reflected on an object in the embodiment of the present invention.
12 is a view showing an example of a form in which a signal is irradiated and a reflected signal is received as the radar rotates in the parking plane sensing system according to the embodiment of the present invention.
13 is a diagram illustrating an example of a signal detection algorithm using a moving radar in a parking plane sensing system according to an embodiment of the present invention.
FIG. 14 is a diagram illustrating an embodiment in which a parking surface sensing system using a radar according to an embodiment of the present invention manages a plurality of parking surfaces.
Fig. 15 is a diagram showing an example of a received signal waveform acquired while managing a plurality of parking surfaces using one radar shown in Fig. 14. Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

First, the terminology used in the present application is used only to describe a specific embodiment, and is not intended to limit the present invention, and the singular expressions may include plural expressions unless the context clearly indicates otherwise. Also, in this application, the terms "comprise", "having", and the like are intended to specify that there are stated features, integers, steps, operations, elements, parts or combinations thereof, But do not preclude the presence or addition of features, numbers, steps, operations, components, parts, or combinations thereof.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The present invention relates to a method and system for detecting a parking lot vehicle using a radar, and more particularly, to a method and system for detecting a parking lot vehicle using a radar, more specifically, detecting a plurality of parking faces using a single radar and detecting the position between a radar and a parking surface, A method of using an algorithm for correcting a detected signal error is disclosed.

Generally, a radar is a device that measures the direction of an object and measures its distance and direction by measuring the time until the received wave is sensed and reflected waves reflected from the object are detected by using the directivity of the radio wave.

First, before explaining a parking lot vehicle detection method and system using a radar according to the present invention, an UWB (ultra-wide band) UWB radar will be described with reference to FIG. 1 to FIG.

Let's take a look at a radar using UWB (ultra-wide band) ultra-wideband. UWB guarantees high speed of 100Mbps ~ 1Gbps and can transmit 100Mbps data with stable fluctuation and consumes less power, while UWB uses high bandwidth of more than several GHz. Lt; / RTI > That is, the characteristic of UWB is that it transmits very short pulses over a very wide frequency spectrum.

1 is a diagram showing a schematic configuration diagram of an ultra-wideband radar.

1, the UWB radar 100 includes a transceiver 110 for supporting wireless data transmission and reception, a transmission antenna 120 for propagating an UWB signal, and a transmission antenna 120 for transmitting the UWB signal to a moving object 101, And a receiving antenna 130 for receiving reflected waves that are reflected by the antenna 103 and the like.

The transceiver 110 propagates an ultra-wideband pulse signal through the transmission antenna 120 and analyzes a reflection signal received through the reception antenna 130. [ The transceiver 110 includes a control unit 111, a pulse generating unit 113, a time delay unit 115, an amplifier 117 and a sampler 119. [

The pulse generator 113 converts a signal transmitted from the controller 111 into various types of pulse waveforms, and the time delay unit 115 affects whether or not the pulse signal is time delayed. The transmission antenna 120 propagates the pulse waveform generated by the pulse generator 113 to the outside.

The amplifier 117 amplifies the reflection signal received through the reception antenna 130, and the sampler 119 samples the amplified signal at high speed. At this time, similarly, it can be delayed for a predetermined time in the sampling process by the time delay unit 115. The sampled signal is transmitted to the control unit 111, and the control unit 111 detects an object based on a signal change of the transmission signal based on the sampled reception signal. In addition, the control unit 111 may analyze the time taken until the propagated signal is received, and measure the distance to the object.

2 is a diagram showing a schematic configuration diagram of a transmitting antenna and a receiving antenna of an UWB radar.

2 (a), a pulse signal 112b is generated in a pulse generator 113 by receiving a digital signal 112a transmitted from a controller 111, and propagated through a transmission antenna 120. FIG.

2 (b), a signal received through the receiving antenna 130 is amplified by an amplifier 117 and a signal 116 delayed by a predetermined time through a time delay unit 115 is sampled by a sampler 119 And the sampler 119 samples the reception signal delayed by a predetermined time at high speed.

FIG. 3 is a diagram illustrating an example of a signal and a signal sampling process of a transmission signal and a reception signal in an UWB radar.

Referring to FIG. 3, the propagated transmission signal 301 is propagated in the form of a pulse train in which pulse groups continuously appear in time at predetermined intervals, each pulse group is composed of a predetermined period (Tr) (T). The received signal 303 is received as a pulse signal of a changed form in contrast to the transmitted signal 301 and the sampler 119 applies a real time sampling signal 305 to the received signal 303 to perform a sampling operation.

The communication equipment using the UWB radar described in FIGS. 1 to 3 can perform object detection and distance measurement through a rough flow as shown in FIG.

4 is a schematic flow diagram of a method for performing object detection and distance measurement in an UWB radar.

4, the transmission antenna 120 propagates the pulse-converted transmission signal (S410). When the reception antenna 130 receives the reflected wave signal while the transmission signal is reflected by an object or the like (S420) The controller 110 removes a reflection obstacle clutter such as echo caused by unnecessary reflected waves in the received signal (S430). At this time, a clutter map is generated to remove the clutter, and the clutter-removed detection signal can be extracted by reflecting the clutter map on the received signal.

Thereafter, the transceiver 110 senses an object on the basis of the detection signal from which the reflection obstructor is removed (S440), and calculates the distance to the sensed object (S450).

As described above with reference to FIGS. 1 to 4, the UWB radar used to detect an object and calculate the distance to a target can be used to detect whether or not a vehicle is parked on a parking lot in a parking lot. That is, an impulse-type UWB radar is used to distinguish whether the vehicle is parked on the parking surface and whether the vehicle is not parked.

5 is a schematic block diagram illustrating a system for detecting a plurality of parking surfaces using a radar according to an embodiment of the present invention.

Since the configuration diagram of the embodiment of FIG. 5 is for illustrating the configuration for implementing the features of the present invention, the detailed configuration of the radar system is simplified and shown. Generally, the configuration of the radar system and a detailed description thereof Is omitted. In addition, the radar system embodying the present invention is not limited to the configuration shown in FIG. 5, but may selectively include various configurations that may be included in a known radar system.

5, a radar system 500 according to an embodiment of the present invention basically includes a transmitter 510, a receiver 520, a signal processor 530, a signal corrector 540, a motor 550, And an output unit 560.

The transmitting unit 510 roughly includes a pulse generator and a controller to generate and propagate a radar transmission signal. In this case, the transmission signal may include various frequencies depending on the object detection purpose and the limiting condition of the radar And an ultra-wide band (UWB) may be applied as an example. The transmission signal generated by the transmission unit 510 is propagated through the transmission antenna 515.

The receiving unit 520 receives the reflected wave signal for the transmitting signal transmitted from the transmitting unit 510 through the receiving antenna 525 and extracts a necessary portion from the received signal including a sampler or the like. At this time, though not shown in FIG. 5, the synchronization with the transmission signal for sampling the sampler can be preceded.

The signal processing unit 530 determines an object detection signal in the sampled signal and detects the object, and generates information such as the position and distance of the object. For example, as the signal is transmitted to the sensing coverage at the transmitter 510 and the received signal is reflected at the receiver 520, the signal processor 530 determines whether the vehicle is parked on one or more parking faces included in the sensing coverage Can be detected.

As an example of the vehicle detection scheme of the signal processor 530, a detection algorithm using template matching between a transmission signal and a reception signal can be used. Template matching is an operation of extracting a given figure from an image by a figure recognizing process. The signal processor 530 compares the pattern of the sampled received signal with a predetermined template matching table to detect whether the vehicle is located on the parking surface have.

In addition, the signal processor 530 can expand the detection coverage by using a vehicle detection algorithm for multiple parking detection based on template matching.

Preferably, a plurality of transmission signals are propagated for more accurate object detection, a plurality of reception signals are received, and a clutter map is generated based on the plurality of reception signals. Then, Noise or error can be corrected by removing the signal.

Meanwhile, the signal processor 530 may be implemented by a specialized device having functions such as arithmetic operation and storage within the radar system 500, but it is preferable to use a device such as a PC capable of performing a kind of arithmetic operation It can also be applied.

The signal correction unit 540 provides a function of correcting the signal to remove an error in the processing of the received signal in the signal processing unit 530. For example, when detecting objects through a radar and measuring distances, shadow effects or errors due to multi-path phenomena may occur.

A shadow effect is a phenomenon in which a radar indicator appears as a non-target area or a distorted image of an actual object as a shielded area is generated from radar irradiation by an interventional medium or an absorption medium that affects an object during radar measurement . The multipath phenomenon refers to a phenomenon in which a plurality of signals appear on a moving object, and the propagation of the reflected waves to the object is reflected on another object and reaches the radar, and thus the propagation of different paths to the object is received by the radar.

The signal correcting unit 540 performs a correcting function for removing clutters mixed with the received signal and can perform a function of correcting an error due to the shadow effect or the multipath phenomenon described above.

Likewise, the signal correction unit 540 may be implemented by a specialized device having functions such as arithmetic operation and storage within the radar system 500 for correcting errors in the radar signal, It is possible to apply a device such as a PC that can be performed.

The motor unit 550 supports the movement of the transmission antenna 515 and the reception antenna 525 according to the signal processing process of the signal processing unit 530. The radar system 500 according to the embodiment of the present invention includes a transmission antenna 515 and a reception antenna 525 with the support of the motor unit 550 connected to the transmission antenna 515 and the reception antenna 525, To rotate at an angle. Accordingly, the radar system 500 can manage a plurality of parking planes while transmitting radio waves into the sensing coverage and receiving the reflected signals. At this time. The operation of the motor unit 550 can be controlled according to the signal processing algorithm of the signal processing unit 530. [

The output unit 560 outputs the information generated by the signal processing unit 530.

Hereinafter, a method of detecting an object using the template matching technique in the radar system shown in FIG. 5 will be described with reference to FIG.

Referring to FIG. 6, when the transmitter 510 of the radar system 500 examines a signal and a predetermined period of time elapses, the receiver 520 receives the original signal, and the size of the received original signal is divided into N (S601). Basically, the radar system is characterized by propagating N transmission signals, receiving N or less received signals to sense an object, and receiving N received signals is characterized in that N numbers are arranged for each received signal As shown in Fig.

When N received signals are received, a band pass filter is passed to remove the noise included in the received signal (S602).

The clutter map is applied to the received signal from which the noise has been removed to initialize unnecessary variables other than the object detection (S603).

Then, the degree of signal similarity using Template Matching with the transmission signal is calculated for the i-th received signal among the N received signals (S604 to S606).

Template matching is an algorithm used to determine whether two signals are similar, and various algorithms can be used. In the embodiment of the present invention, template matching is performed using a cross correlation.

Hereinafter, template matching will be briefly described with reference to FIGS. 7 and 8. FIG.

Template matching using cross-correlation is used in signal processing to quantify how one signal resembles another signal. FIG. 7 is a diagram schematically illustrating calculation of a cross-correlation between two signals. FIG.

7 (a) is a schematic representation of a convolution integration operation of the first signal function f and the second signal function g, and Fig. 7 (b) And the second signal function g is integrated by cross correlation and the second signal function g is integrated by auto-correlation with respect to the second signal function g. Which is a graphical representation.

The calculation formula for the convolution operation illustrated in FIG. 7A can be expressed as Equation 1 with respect to the two signals f and g.

[Equation 1]

The calculation formula for the cross-correlation calculation illustrated in FIG. 7 (b) can be expressed by the following equation (2).

&Quot; (2) "

In the above equation (2), the g [n + m] portion has an important meaning in the template matching because the cross correlation operation comes from the convolution operation. In the above equations (1) and (2), g [n + m] in the equation (2) together with (f * g) [n] . In other words, the cross correlation operation is a form in which the kernel function g is input in the direction opposite to the convolution. This is also illustrated in Figs. 7 (a) and 7 (b).

In the embodiment of the present invention, template fill matching is performed using a cross correlation between a transmission signal and a received signal. Template matching through cross-correlation is a feature of speed. Computing the cross-correlation operation in the frequency domain has only a simple multiplication operation, so that the calculation can be performed at a very high speed using the Fast Fourier Transform.

FIG. 8 is a diagram schematically illustrating a template matching process to be used by a parking surface sensing system according to an embodiment of the present invention.

FIG. 8A shows a waveform of a transmission signal propagating in the radar system 500, and FIG. 8B is a diagram showing an example of a signal waveform according to a template matching process.

Template matching is performed from the beginning to the end of the received signal 802 and performs an operation of multiplying the value of the received signal 802 by the value of the transmitted signal 801. The degree of similarity between the calculated result and the transmitted signal 801 It is the process of calculating. 8B, the value of the transmission signal 801 is calculated for a reception signal corresponding to the first section 803 of the reception signal 802, And repeats the calculation process between the received signal and the transmitted signal while moving. In this process, a second section 804 of the received signal, which is the most similar to the transmission signal 801, appears, and a signal value larger than the threshold value is derived in the second section 804.

In this manner, whether or not an object exists at the corresponding position can be determined according to whether the template matching result value using the cross correlation between the transmission signal and the reception signal is equal to or greater than a threshold value.

6, the template matching with the transmission signal is performed on the i-th received signal, and the template matching result is compared with a predetermined threshold value (S607).

If the template matching result is larger than a predetermined threshold value, it is determined that the object is located at a position corresponding to the i-th received signal (S608). If the template matching result is smaller than the predetermined threshold value, The template matching process is repeated (S609).

Although not shown in FIG. 6, when the template matching result value is equal to or greater than the threshold value, the result value and the corresponding received signal can be recorded in a predetermined memory.

The radar detection algorithm according to an embodiment of the present invention has been schematically described with reference to FIGS. 6 to 8. FIG.

Hereinafter, a case in which the above-described radar detection algorithm is applied to a parking surface sensing system for sensing a plurality of parking surfaces will be described. In the following embodiments, signals may denote the signals themselves, but they may also mean the magnitudes of the signals depending on the circumstances, which need to be properly interpreted as needed.

The characteristics for improving the accuracy of vehicle detection on the parking surface in the vehicle sensing method using the radar according to the present invention will be described.

9 is a diagram illustrating an example of a received signal waveform according to whether or not a vehicle is parked on a parking surface, according to an embodiment of the present invention.

9A shows an example of the reception signal 903 received by the radar 901 in the absence of a vehicle on the parking surface 902 according to time. The reception signal 903 at this time is a constant The signals of the waveform appear in a continuous form.

9B shows an example of the received signal 905 received by the radar 901 when the vehicle 904 is parked on the parking surface 902 according to a time flow. At this time, as a part of the transmission signal propagated into the parking surface 902 is affected by the reflection signal generated by the reflection by the vehicle 904, the reception signal 905 is received by the reception signal 903 The signal change occurs.

Therefore, it is possible to judge whether or not an object in the space is located from the waveform of the received signal.

However, since the parking method or the parking ability is different for each driver and not all the vehicles are parked in the parking plane, the waveform of the received signal when the vehicle is parked on the parking surface is not constant, .

10 is a view for explaining an example of a form in which a signal is reflected on an object according to an embodiment of the present invention.

Specifically, due to the characteristics of the steel structure constituting the vehicle body, the signal propagated to the vehicle is totally reflected along the input direction with respect to the iron. 10A, when the axis of the steel structure 1002 is positioned orthogonally to the direction in which the signal propagates in the radar 1001, the transmission wave 1003 propagated to the steel structure 1002, So that the reflected wave 1004 is formed. That is, most of the reflected wave 1004 due to the steel structure 1002 is received by the radar 1001.

On the other hand, when the steel structure is obliquely positioned in the direction in which the radar signal propagates, that is, when the axis of the structure forms 0 to 90 degrees or 90 to 180 degrees with the propagation direction, .

7 (b), when the axis of the iron structure 1002 is inclined at an angle of 45 degrees with respect to the direction in which the radar signal propagates, most of the transmission wave 1003 is radiated by the total reflection phenomenon 1001 are not positioned. That is, most of the reflected wave 1005 due to the steel structure 1002 is reflected in the other direction, resulting in loss of received signal of the radar 1001.

The reflected wave loss due to the position between the target object and the radar system may occur in the positional relationship as shown in Fig.

11 is a view for explaining another example of a form in which a signal is reflected on an object in the embodiment of the present invention.

11, when the radar 1101 is positioned at a predetermined height H from the ground and irradiates a signal at a fixed position, the transmission signal 1103 propagated in the radar 1101 is transmitted through the fixed angle range? 1 -θ2 to the top of the vehicle 1102. At this time, it is assumed that the radar 1101 is fixed. Therefore, as described above with reference to FIG. 10, the reflected wave with respect to the signal irradiated to the upper end of the vehicle is reflected by the portion 1104 in the left-right direction, and the signal irradiated to the vehicle in the orthogonal direction The reflected wave 1105 is reflected toward the radar 1101.

That is, when the radar 1101 is located higher than a certain height above the vehicle 1102, it can propagate the signal to two or more vehicles with one radar, but a part of the reflected waves may be lost and the signal detection accuracy may be reduced.

However, if the radar according to the embodiment of the present invention is moved like rotation, the signal irradiation range can be expanded according to the radar movement. In this regard, the waveform of the received signal according to the positional relationship between the vehicle and the radar will be described with reference to Fig.

12 is a view showing an example of a form in which a signal is irradiated and a reflected signal is received as the radar rotates in the parking plane sensing system according to the embodiment of the present invention.

Referring to FIG. 12, a radar 1201 that propagates a signal in a certain angle range (.theta.) Is rotated constantly with respect to a fixed axis, so that signals are irradiated to the I region, the II region, and the III region. The waveform of the received signal varies depending on whether the vehicle 1202 exists in each region due to the variation of the signal propagation region due to the movement of the radar 1201. [ For example, since the vehicle 1202 is not located at the positions 1 and 3, no reflected wave is generated, and the waveform of the received signal over time can be detected as a continuous waveform. On the other hand, in the position (2), the received signal fluctuates due to the influence of the reflected wave by the vehicle 1202. This can be explained in view of the above-described feature that the waveform of the received signal varies depending on whether or not the vehicle is present in FIG.

Next, a signal sensing algorithm for improving the signal sensing accuracy based on the radar signal sensing characteristics described with reference to FIGS. 6 to 9 will be described.

FIG. 13 is a diagram illustrating an example of a signal sensing algorithm using a moving radar in a parking plane sensing system according to an embodiment of the present invention. First, based on the embodiment described above with reference to FIG. 10, An algorithm for detecting whether or not the vehicle is parked on the parking surface will be described. 5, the signal processor 530 detects the presence or absence of a vehicle by applying the following algorithm to the received signal transmitted from the receiver 520, and controls the drive of the motor unit 550 .

As described above with reference to FIG. 10, the radar system according to the embodiment of the present invention propagates a transmission signal to three areas divided into areas I, II, and III for each parking surface and acquires a reception signal .

Accordingly, referring to FIG. 13, the initial value of the number (i) of received signals to be received for the first parking face is set to 0 (S1301). Then, the radar signal is divided and divided into three areas, that is, I region, II region, and III region on the first parking surface, and the i th receiving signal can be added up to 2 when the initial value is 0 have.

When the receiving unit 520 acquires the i-th received signal (S1302), the signal processing unit 530 performs template matching on the i-th received signal (S1303). C (i) denotes an arrangement for storing values of template-matched values for the i-th radar signal.

Next, when there is an area in which no signal has propagated into the parking plane (i <2), i + 1th radar signal is used (S1304, S1305). To this end, the motor unit 550 is driven to drive a motor connected to the radar so that the UW radar rotates by a first angle (S1306). The first angle is assumed to be a value that sets the rotation angle of the radar so that the radar can irradiate a signal to another area of the same parking surface based on the radar irradiation range. For example, the first angle is assumed to be a rotation angle corresponding to the movement from the I region to the II region and from the II region to the III region within one parking plane.

The steps S1302 to S1306 may be repeated until i = 2, and the radar survey range may shift from the II region to the III region.

On the other hand, when a radar signal is irradiated to three predetermined regions on the first parking surface (i? 2), among the template matching values for the radar signal (i = 1) for region II, the maximum value max (1) is compared with a predetermined first reference value (S1307). Since the region II corresponds to the central region of the parking surface relative to the other regions I and III, the radar signal for the region II If the maximum value max (c (1)) of the template matching value is greater than the first reference value, it can be determined that the vehicle exists on the first parking surface (S1309).

If the maximum value (max (c (1)) of the template matching value for the region II is not larger than the first reference value, the template matching value of the radar signal for the region I, region II, and region III (Diff (C (0), C (1), C (2)) at which the variation amount of the template matching value is maximum for a specific section is derived and compared with a predetermined second reference value (S1308) For example, when the vehicle is parked at a position of 3 to 4 meters from the radar, a predetermined interval for analyzing the variation amount of the template matching value Will be 3-4 meters.

That is, when the maximum amount of change (Diff (C (0), C (1), C (2)) of the template matching value for the radar signal in the specific section spaced by a specific distance from the radar is equal to or greater than the second reference value, It is determined that the vehicle exists on the parking surface (S1309). If not, it is determined that the vehicle does not exist on the first parking surface (S1310).

Then, the motor unit 550 is driven to rotate the radar by the second angle in order to detect the presence or absence of the vehicle on the second parking surface adjacent to the first parking surface (S1311).

The second angle is assumed to be a radar rotation angle for moving the radar irradiation area to the second parking surface adjacent to the first parking surface, unlike the first angle. Therefore, the second angle may be a value larger than the first angle. As the radar system according to the embodiment of the present invention rotates using a motor to detect a neighboring parking surface, the process returns to step S1301 in which the radar receiving signal is initialized, and the above procedure is repeated.

FIG. 14 is a diagram illustrating an embodiment in which a parking lot surface sensing system using a radar according to an embodiment of the present invention manages a plurality of parking surfaces, FIG. 15 is a diagram illustrating a plurality of parking Fig. 8 is a diagram showing an example of a received signal waveform acquired while managing a surface.

Referring to FIG. 14, a radar 1401 according to an embodiment of the present invention has a sensing coverage 1400 including a plurality of parking surfaces. The parking plane sensing system can sequentially manage a plurality of parking planes 1402 to 1407 included in the sensing coverage 1400 according to driving of the motor connected to the radar 1401. That is, the radar system senses the presence or absence of a vehicle with respect to one parking surface, drives the motor so that the radar survey category moves to the neighboring parking surface, and detects the presence of all the parking surfaces 1402 to 1407 included in the sensing coverage The presence or absence of the vehicle can be detected continuously or discontinuously.

Accordingly, as illustrated in FIG. 15, the radar moves from the first parking surface 1402 to the sixth parking surface 1407 to transmit a transmission signal and receive a reception signal therefrom. The vehicle is present in the first to third parking surfaces 1402 to 1404, the fifth parking surface 1406 and the sixth parking lot 1407 of the plurality of parking surfaces shown in FIG. 14, The waveform of the fourth reception signal 1504 corresponding to the fourth parking surface 1405 is the remaining reception signals 1501 to 1503, 1505 and 1506, as shown in Fig. 15, . It can be seen that the fourth received signal 1504 is not influenced by the reflected wave due to the vehicle and the received signal waveform appears constant.

As described above, according to the present invention, when performing object detection while rotating a radar using a motor, it is possible to enlarge the detection coverage corresponding to one radar, and it is possible to detect a plurality of parking faces with one radar can do. In addition, by proposing a method for correcting an error due to a signal loss caused by a positional relationship between a radar and a detection target, it is possible to more accurately detect an object and efficiently drive the radar system.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments of the present invention are not intended to limit the scope of the present invention but to limit the scope of the present invention. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents thereof should be construed as being included in the scope of the present invention.

Claims (12)

A method for detecting a presence of a vehicle in a parking space using a radar,
(a) sequentially propagating a plurality of radar transmission signals to a parking surface using a radar and a motor connected to the radar, and sequentially receiving a plurality of the reflected signals;
(b) sequentially performing template matching on the plurality of received signals;
(c) deriving a template matching maximum value for an arbitrary received signal among the plurality of received signals based on the template matching result, and comparing the template matching maximum value with a predetermined first reference value; And
(d) determining whether the vehicle exists on the parking surface according to the comparison result,
Wherein the radar repeatedly performs the steps (a) to (d) for a plurality of parking surfaces included in the detection coverage of the radar as the radar rotates at a certain angle by supporting the driving of the motor. A method for detecting a plurality of parking planes using the method. The method according to claim 1,
The step (a)
Dividing a region where the radar transmission signal propagates into n partial regions on the parking surface; And
And propagating a transmission signal for each of the n partial areas and receiving a reflected wave signal therefrom. 3. The method of claim 2,
Wherein the n partial areas within the parking surface are divided in a direction toward the other surface facing the one surface with respect to the one surface of the parking surface. 3. The method of claim 2,
Wherein the radar transmits a radar transmission signal sequentially to the n partial areas while rotating at a first angle in accordance with the motion support of the motor. 5. The method of claim 4,
The step (b)
And the radar sequentially propagates the radar transmission signals to the n partial areas while rotating the first angle by the first angle, and sequentially performs template matching on the plurality of reception signals received for each of the n partial areas A plurality of parking face detection methods using a radar. 6. The method of claim 5,
The step (c)
And comparing a template matching value of a received signal in an arbitrary partial area of the n partial areas within the parking plane with the first reference value. The method according to claim 6,
The step (d)
If the template matching value is larger than the first reference value, it is determined that an object in the arbitrary partial area is located, and a received signal section in which the tamper matching value is maximized is analyzed, And the distance between the first and second radar images is calculated. The method according to claim 6,
The step (d)
If the template matching value is smaller than or equal to the first reference value, deriving a variation amount of the template matching value in the same received signal interval for each of the n partial regions;
Comparing a maximum value of the amount of change in the derived template matching value with a predetermined second reference value; And
And determining whether or not the vehicle is present according to the result of the comparison. 9. The method of claim 8,
Wherein a distance between the radar and the object is derived by analyzing a received signal section in which a maximum value among the derived amounts of variation of the template matching value is derived. The method according to claim 1,
Rotating the radar at a second angle by driving support of the motor after determining whether the vehicle exists on the parking plane; And
(A) to (d) for the other parking surface adjacent to the parking surface as the radar rotates at the second angle, Face detection method. The method according to claim 1,
Wherein the template matching value for the received signal is a calculated value according to a position at which the received signal is received based on the radar. The method according to claim 1,
Wherein the template matching step comprises:
Wherein a cross correlation value between the transmission signal and the reception signal is calculated.

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