Method for generating vehicle control signals based on magnetic paint lane and apparatus therefor

Abstract

Disclosed herein are methods for generating vehicle control signals based on a magnetic paint lane and apparatuses thereof. The method includes generating a magnetic induction signal corresponding to an alternating magnetic pattern from the magnetic paint lane, performing noise filtering on the magnetic induction signal to generate a noise-removed magnetic induction signal, and controlling an operation of a vehicle based on the noise-removed magnetic induction signal.

Description

Technical Field

[0001] This disclosure generally relates to a technique for controlling a vehicle by detecting signals generated from lanes marked with magnetic paint, and more specifically, to a technique for clearly detecting signals for controlling the operation of the vehicle by performing noise filtering on the detected magnetic induction signals corresponding to alternating magnetic patterns. Background Technology

[0002] Unless otherwise stated herein, the content described in this section is not prior art to the claims of this application, nor is it acknowledged as prior art by virtue of its inclusion in this section.

[0003] An autonomous driving system can apply magnetic information detected in lanes marked with magnetic paint to the driving of an autonomous vehicle.

[0004] For example, lanes are marked on the road using magnetic paint containing ferromagnetic particles, alternating magnetic patterns are applied to the lanes using an alternating (AC) magnetic field, and the alternating magnetic patterns are detected using magnetic sensors provided in autonomous vehicles, thereby providing driving-related information (e.g., vehicle speed or lane information) to the driver or passengers in the autonomous vehicle.

[0005] Here, the information provided related to vehicle driving may correspond to the frequency of the alternating magnetic pattern or the amplitude of the detected magnetic signal.

[0006] Meanwhile, vibrations during driving and outdoor power transmission lines may make it difficult for vehicles to detect magnetic signals generated from magnetic paint lanes with alternating magnetic patterns, as these act as noise in the signals detected by the vehicle's magnetic sensors.

[0007] [Related Technical Documents]

[0008] (Patent Document 1) Korean Patent Application Publication No. 10-2015-0125115, published on November 9, 2015, entitled "Method for generating a driving path with applied magnetic powder and a detection device using the method". Summary of the Invention

[0009] The purpose of this disclosure is to clearly detect the magnetic signals generated from a magnetic paint lane with an alternating magnetic pattern, thereby safely controlling the vehicle.

[0010] Another objective of this disclosure is to achieve safe operation of autonomous vehicles by eliminating noise generated by other vehicles, power transmission lines, vibrations of the autonomous vehicle, etc., in an autonomous vehicle system that uses magnetic signals generated from the magnetic paint lane to drive the autonomous vehicle.

[0011] Another objective of this disclosure is to improve the signal-to-noise ratio and the safety of autonomous vehicles by changing the cutoff frequency value in the frequency filter in real time to adapt to the frequently changing vehicle speed during driving.

[0012] The purpose of this disclosure is not limited to the above-described purposes; obviously, other purposes may be derived from the following description.

[0013] To achieve the above objectives, a method for generating vehicle control signals based on a magnetic paint lane according to an embodiment of the present disclosure includes: generating a magnetic induction signal corresponding to an alternating magnetic pattern from the magnetic paint lane; performing noise filtering on the magnetic induction signal to generate a noise-removed magnetic induction signal; and controlling the operation of the vehicle based on the noise-removed magnetic induction signal.

[0014] Here, by applying alternating magnetic patterns, the magnetic paint lane can be generated as a spatial period with a length greater than 0 cm and equal to or less than 25 cm.

[0015] Here, noise filtering may include filtering out low-frequency signals with frequencies below a target frequency, which is detected by taking into account the spatial period of the alternating magnetic pattern and the speed of the vehicle.

[0016] Here, noise filtering may include filtering out a first noise frequency component corresponding to the state in which the vehicle is not driven and a second noise frequency component corresponding to the state in which the vehicle's speed change is less than a preset reference level.

[0017] Here, noise filtering may include: changing the characteristics of the filter to correspond to the target frequency detected based on the vehicle's speed.

[0018] Here, the vehicle's speed can be obtained based on information fed back from at least one of the vehicle's speedometer, GPS sensors, or combinations thereof.

[0019] Here, noise filtering may include: setting a passband, the center frequency of which is set to a target frequency; and filtering out noise frequency components not included in the passband.

[0020] Here, the passband can be reset with a setting cycle that takes into account the vehicle's speed.

[0021] Here, the set period can be calculated based on the emergency braking distance corresponding to the vehicle's speed and the driving distance corresponding to the vehicle's speed for a preset time.

[0022] Here, noise filtering may include reducing the passband width when the amplitude difference between the signal corresponding to the target frequency and the signal corresponding to the noise frequency component is less than a preset reference difference.

[0023] Here, the passband can correspond to the range from the low cutoff frequency to the high cutoff frequency. The low cutoff frequency and the high cutoff frequency are set to correspond to the following signals, the amplitude of which is smaller than the amplitude of the signal at the center frequency by a preset reference amplitude.

[0024] Furthermore, in order to achieve the above objectives, an apparatus for generating vehicle control signals based on a magnetic paint lane according to an embodiment of the present disclosure includes: a processor for generating a magnetic induction signal corresponding to an alternating magnetic pattern from the magnetic paint lane, performing noise filtering on the magnetic induction signal to generate a noise-removed magnetic induction signal, and controlling the operation of the vehicle based on the noise-removed magnetic induction signal; and a memory for storing the magnetic induction signal.

[0025] Here, by applying alternating magnetic patterns, magnetic paint lanes can be generated with a spatial period of length greater than 0 cm and equal to or less than 25 cm.

[0026] Here, noise filtering may include filtering out low-frequency signals with frequencies below a target frequency, which is detected by taking into account the spatial period of the alternating magnetic pattern and the speed of the vehicle.

[0027] Here, noise filtering may include filtering out a first noise frequency component corresponding to the state in which the vehicle is not driven and a second noise frequency component corresponding to the state in which the vehicle's speed change is less than a preset reference level.

[0028] Here, noise filtering may include: changing the characteristics of the filter to correspond to the target frequency detected based on the vehicle's speed.

[0029] Here, the vehicle's speed can be obtained based on information fed back from at least one of the vehicle's speedometer, GPS sensors, or combinations thereof.

[0030] Here, noise filtering may include: setting a passband, the center frequency of which is set to a target frequency; and filtering out noise frequency components not included in the passband.

[0031] Here, the passband can be reset with a setting cycle that takes into account the vehicle's speed.

[0032] Here, the set period can be calculated based on the emergency braking distance corresponding to the vehicle's speed and the driving distance corresponding to the vehicle's speed for a preset time.

[0033] Here, noise filtering may include reducing the passband width when the amplitude difference between the signal corresponding to the target frequency and the signal corresponding to the noise frequency component is less than a preset reference difference.

[0034] Here, the passband can correspond to the range from the low cutoff frequency to the high cutoff frequency. The low cutoff frequency and the high cutoff frequency are set to correspond to the following signals whose amplitude is smaller than the center frequency signal by a preset reference amplitude. Attached Figure Description

[0035] The above and other objects, features and advantages of this disclosure will become more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0036] Figure 1 This is a flowchart of a method for generating vehicle control signals based on a magnetic paint lane, according to an embodiment of the present disclosure.

[0037] Figure 2 This is an illustration showing an example of a target frequency detected according to the present disclosure, taking into account the vehicle speed and the spatial period of the enamel lane.

[0038] Figure 3 This is an illustration showing an example of frequency components detected when a vehicle starts but is not driving on a regular road;

[0039] Figure 4 This is an illustration showing an example of the frequency components detected when a vehicle is traveling at 50 km / h, with an alternating magnetic pattern applied so that the spatial period of the magnetic paint lane is 30 cm.

[0040] Figure 5 This is an illustration showing an example of the frequency components detected when a vehicle is traveling at 50 km / h, with an alternating magnetic pattern applied so that the spatial period of the magnetic paint lane is 10 cm.

[0041] Figures 6-9 This is a diagram illustrating an example of the process for filtering out a first noise frequency component and a second noise frequency component according to the present disclosure.

[0042] Figures 10-11 It shows the... Figure 5 The illustration shows an example of the results of filtering the frequency components to correspond to a fixed cutoff frequency (40Hz or 80Hz).

[0043] Figure 12 This is an illustration of an example of filtering the frequency components detected when a vehicle is traveling at 30 km / h, using a passband with a frequency range of 71 to 101 Hz according to the present disclosure, with an alternating magnetic pattern applied so that the spatial period of the magnetic paint lane is 10 cm.

[0044] Figure 13 This demonstrates the use of a passband with a frequency range of 76–96 Hz in conjunction with… Figure 12An illustration of an example of the results of filtering frequency components detected under the same conditions;

[0045] Figure 14 It is shown in Figure 12 An example illustration of the filtering results after resetting the passband to 132-153Hz when the vehicle speed increases to 50km / h;

[0046] Figure 15 This is an illustration showing an example of a passband according to this disclosure;

[0047] Figure 16 This is a flowchart illustrating in detail the process of setting the passband according to embodiments of the present disclosure;

[0048] Figure 17 This is a flowchart illustrating in detail the process of setting the passband setting cycle according to embodiments of the present disclosure; and

[0049] Figure 18 This is a block diagram illustrating an apparatus for generating vehicle control signals based on a magnetic paint lane, according to an embodiment of the present disclosure. Detailed Implementation

[0050] The present disclosure will now be described in detail with reference to the accompanying drawings. Repetitive descriptions and descriptions of known functions and configurations that are deemed unnecessary to obscure the main points of the disclosure will be omitted. The embodiments of the present disclosure are intended to fully describe the disclosure to those skilled in the art. Therefore, the shapes, dimensions, etc., of components in the drawings may be exaggerated to make the description clearer.

[0051] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0052] Autonomous vehicles that perform autonomous driving by detecting magnetic signals generated from magnetically painted lanes with alternating magnetic patterns are susceptible to malfunctions because nearby noise can hinder accurate signal detection. Examples of such noise include nearby vehicles, electrical noise from power transmission lines (60Hz in South Korea), or vibration noise from the autonomous vehicle itself due to uneven road surfaces.

[0053] To address this issue, various frequency filters designed to improve the signal-to-noise ratio can be used with the magnetic sensors installed in the vehicle. In such frequency filters, filtering is performed using a physical filter composed of RLC elements (resistors, inductors, and capacitors) corresponding to a cutoff frequency set to a fixed value during filter manufacturing. Here, to change the cutoff frequency value, the passive RLC elements in the frequency filter module need to be replaced.

[0054] However, because the target frequency (which must be detected by the autonomous driving system using alternating magnetic patterns) changes frequently according to the vehicle's rapidly changing speed, such a frequency filter using a fixed cutoff frequency is insufficient for smooth noise filtering and may lead to autonomous vehicle malfunctions.

[0055] Furthermore, in the case of sensor modules manufactured for detecting signals in vehicles, the cutoff frequency or bandwidth is often set to have a wide range in order to make the sensor module suitable for general use or due to manufacturing difficulties. Therefore, it is difficult to improve the signal-to-noise ratio.

[0056] To address the aforementioned problems, the present disclosure aims to provide a method for effectively filtering out noise components irrelevant to driving based on vehicle speed and for clearly detecting signals of alternating magnetic patterns based on magnetic paint lanes, thereby achieving safe vehicle operation.

[0057] Figure 1 This is a flowchart illustrating a method for generating vehicle control signals based on a magnetic paint lane, according to an embodiment of the present disclosure.

[0058] refer to Figure 1 In a method for generating vehicle control signals based on a magnetic paint lane according to an embodiment of the present disclosure, in step S110, a magnetic induction signal corresponding to an alternating magnetic pattern is generated from the magnetic paint lane.

[0059] Here, a magnetic sensor installed in the vehicle can be used to acquire magnetic induction signals.

[0060] Here, by applying alternating magnetic patterns, magnetic paint lanes can be generated with a constant spatial period. The spatial period of the magnetic paint lanes may affect the magnetic induction signals collected when autonomous vehicles are driving.

[0061] For example, refer to Figure 2 The distance S (in cm) traveled per second is calculated based on the vehicle's speed v. Dividing this distance by the spatial period (in cm) of the magnetic lane allows us to calculate the number of times the alternating magnetic pattern is detected per second of vehicle travel. This calculated number of alternating magnetic pattern detections corresponds to the target frequency f that the vehicle must detect. v . Figure 2 Calculate the target frequency f v The process can be represented by the following equation (1):

[0062]

[0063] That is, the target frequency that the vehicle must detect changes according to the spatial period of the magnetic paint lane, which can greatly affect the control of the vehicle.

[0064] Therefore, in order to clearly isolate the signals required to control vehicle movement from the magnetic induction signals, it is necessary to set the spatial period of the magnetic paint lane so that the required signals can be distinguished from noise.

[0065] Here, electrical noise from nearby vehicles or power transmission lines (60Hz in South Korea) is considered noise along with noise generated by vibrations from the vehicle itself or uneven road surfaces.

[0066] Vehicle vibration noise, typically generated by the vehicle itself or vibrations from uneven road surfaces, is measured at approximately 30 Hz or lower. Additionally, nearby vehicles may generate noise while the vehicle is in motion, but considering the maximum and minimum speed limits on the road, the relative speed between vehicles generally does not exceed 50 km / h. Furthermore, in South Korea, electrical noise at 60 Hz is commonly detected, which is a consistent value detectable regardless of vehicle speed. The harmonics of these noises (frequencies that are integer multiples of the fundamental frequency) also function as noise, but their amplitude is relatively small compared to the fundamental frequency.

[0067] For example, Figure 3 The analysis results show the frequency detected when a vehicle starts but is not driving on a regular road, and refer to... Figure 3 It can be seen that the vehicle's vibration frequency was clearly detected at approximately 26 Hz (①), and 50 Hz, corresponding to its harmonics, was also detected. Furthermore, it can be seen that a frequency of approximately 60 Hz (②), corresponding to AC electrical noise, was detected together with 180 Hz (③), corresponding to its harmonics.

[0068] That is, considering the electrical noise corresponding to 60Hz and vehicle vibration noise equal to or below 30Hz generated near the road, it is necessary to set the spatial period of the magnetic paint lane so that the signal of the alternating magnetic pattern can be clearly distinguished from these frequencies.

[0069] Here, Figure 4 The frequency components detected are shown when the vehicle is traveling at 50 km / h, with an alternating magnetic pattern applied to make the spatial period of the magnetic paint lane 30 cm. Under these conditions, according to... Figure 2 The table shown indicates that the target frequency is expected to occur at approximately 47 Hz.

[0070] The target frequency actually measured while driving was approximately 50 Hz (①), such as Figure 4As shown, this indicates that the vehicle's speed is not constant but varies within the range of 50 to 52 km / h during operation. Simultaneously, it can be observed that noise generated by vehicle vibration, along with its harmonics, is detected at frequencies of 60–70 Hz or lower. Therefore, it is impossible to determine whether the 47–50 Hz frequency to be detected is influenced by vehicle vibration and its harmonics, or is generated by the alternating magnetic patterns of the painted lane. Furthermore, because the detected frequency components include various noises beyond 50 Hz, this could potentially lead to serious malfunctions when driving an autonomous vehicle.

[0071] As mentioned above, the frequency of noise generated for various reasons does not change significantly even when the vehicle accelerates or decelerates. However, the target frequency corresponding to the alternating magnetic pattern changes proportionally with the vehicle's speed, such as... Figure 2 As shown.

[0072] For example, refer to Figure 3 and Figure 4 When comparing the frequency components detected when the vehicle is stationary with those detected when the vehicle is traveling at 50 km / h, it can be seen that, in the case of actual noise detection, only the amplitude changes, while the frequency value does not change significantly.

[0073] That is, it can be seen that in Figure 3 The value shown is the frequency at approximately 26 Hz (①) at which the vibration is attributed to the vehicle. Figure 4 The value is still detected at approximately 26 Hz. Figure 3 The image shows the frequency at approximately 60 Hz (②) that is attributed to electrical noise. Figure 4 The value is shown as still being detected at approximately 60 Hz.

[0074] Therefore, this disclosure aims to propose a method for removing noise components that do not vary much in the low-frequency band by utilizing the spatial period of the magnetic paint lane.

[0075] Similarly, in the method for generating vehicle control signals based on magnetic paint lanes according to embodiments of the present disclosure, in step S120, the magnetic induction signal is noise filtered to generate a noise-removed magnetic induction signal.

[0076] Here, by applying alternating magnetic patterns, the magnetic paint lane can be generated with a spatial period corresponding to a length greater than 0 cm and equal to or less than 250 cm.

[0077] Here, noise filtering may include filtering out low-frequency signals with frequencies below a target frequency, which is detected by taking into account the spatial period of the alternating magnetic pattern and the speed of the vehicle.

[0078] Here, noise filtering may include filtering out a first noise frequency component corresponding to the state where the vehicle is not moving, and a second noise frequency component corresponding to the state where the vehicle's speed change is lower than a preset reference level.

[0079] For example, refer to Figure 2 As can be seen, when an alternating magnetic pattern is applied to give the magnetic paint lane a spatial period of 30cm, the target frequency is 46.3Hz at 50km / h, 55.6Hz at 60km / h, and 64.8Hz at 70km / h. Compared to the noise frequencies mentioned above, the differences between these target frequencies are very small, making it difficult to clearly isolate the target frequencies.

[0080] When the vehicle is traveling at 50 km / h, if an alternating magnetic pattern is applied, such that the spatial period is reduced to 1 / 3 of the original spatial period, giving the magnetic paint lane a spatial period of 10 cm, the target frequency can be detected at approximately 140 Hz (③). Figure 5 As shown. Here, for reference Figure 5 It can be seen that although frequencies attributed to vibration noise (①) and frequencies attributed to electrical noise (②) appear, the target frequency is clearly distinguished from them and detected.

[0081] In other words, when taking into account various noise components, the target frequency can be expected to be set to be equal to or greater than 60Hz.

[0082] Furthermore, considering that most fatal traffic accidents occur at high speeds, accurately detecting the target frequency at speeds of 60 km / h or higher may be crucial for ensuring safety while the vehicle is in motion. Therefore, the spatial period of the magnetic paint lane is set such that the target frequency becomes 60 Hz or higher at speeds of 60 km / h or higher, and alternating magnetic patterns can be applied based on this.

[0083] In the following text, reference will be made to Figures 6 to 9 Describe in detail the process of filtering out the first noise frequency component and the second noise frequency component.

[0084] first, Figure 6 This is a diagram showing the frequency components of the magnetic induction signal detected when a vehicle is traveling at 50 km / h, with an alternating magnetic pattern applied to make the spatial period of the magnetic paint lane 10 cm. (Reference) Figure 6 As can be seen, because a very strong signal corresponding to 10Hz appeared, other frequency components were almost completely hidden.

[0085] To remove noise in this condition, a low-pass filter (LPF) is used to filter the magnetic signal. This LPF only allows signals with frequencies equal to or lower than 80 Hz to pass through, thereby producing a signal such as... Figure 7 The filtered signal is shown.

[0086] Then, from Figure 6 Subtract from the magnetic induction signal shown Figure 7 The filtered signal shown can be used to obtain a signal with low-frequency signals removed, such as... Figure 8 As shown. Here, Figure 8 The signal shown still includes frequency components that can be attributed to vibration noise or electrical noise, but the signal amplitude of the corresponding frequency components is reduced by filtering according to this disclosure.

[0087] when Figure 8 When the signal (as described above, filtered) is frequency converted, it can obtain Figure 9 The results are shown.

[0088] In other words, when showing the frequency components before noise filtering Figure 5 The frequency components after noise filtering are shown. Figure 9 When comparing, it can be seen that, Figure 9 China and Belgium in Figure 5 The target frequency (approximately 138 Hz) was observed more clearly in the image.

[0089] The method described above is used to remove low-frequency signals from magnetic induction signals, thereby easily removing noise signals in the low-frequency band, such as vibration noise or electrical noise.

[0090] Here, noise filtering may include changing the filtering characteristics to correspond to a target frequency, which is based on vehicle speed detection.

[0091] Here, noise filtering may include: setting a passband, the center frequency of which is set to the target frequency; and filtering out noise frequency components not included in the passband.

[0092] For example, Figure 5 The diagram illustrates the frequency components detected when a vehicle is traveling at 50 km / h, with an alternating magnetic pattern applied to make the spatial period of the magnetic paint lane 10 cm, and shows the state without specific noise filtering. Here, consider... Figure 2 The content shown is confirmed. Figure 5 Of the frequencies shown, the frequency corresponding to ③ is the target frequency, and the frequencies corresponding to ① and ② are noise frequencies. Furthermore, it can be seen that the amplitude of the signal corresponding to the target frequency is approximately 10 times that of the signal corresponding to the noise frequency.

[0093] In this case, since most noise has a frequency of 60Hz or lower, when a high-pass filter that only allows signals with a frequency equal to or higher than 60Hz to pass through is used, a signal corresponding to the target frequency (approximately 142Hz) that is expected to be measured can be clearly detected.

[0094] For example, Figures 10 to 11 This illustrates the effect of using a high-pass filter with a fixed cutoff frequency that utilizes physically passive components. Figure 5 The frequency analysis results of the signal shown are obtained when filtering is performed.

[0095] first, Figure 10 This illustrates the use of a high-pass filter with a cutoff frequency set to 40Hz. Figure 5 The signal shown is the result of filtering. Here, when the signal is... Figure 5 frequency components and Figure 10 When comparing the frequency components, it can be seen that only frequency components equal to or below 40Hz are attenuated, and have no effect on the signal corresponding to the target frequency to be actually detected (approximately 142Hz).

[0096] on the contrary, Figure 11 This illustrates the use of a high-pass filter with a cutoff frequency set to 80Hz. Figure 5 The result of filtering the signal shown is that the amplitude of the signal corresponding to the target frequency (approximately 142 Hz) is increased, which is approximately 100 times larger than the amplitude of the signal corresponding to the noise frequency.

[0097] In other words, when Figure 10 frequency components and Figure 11 When comparing frequency components, a high-pass filter with an appropriate cutoff frequency can be used to more clearly identify the signal corresponding to the target frequency, which can help control the vehicle and thus enable safe driving.

[0098] However, high-pass filters formed by passive components using RLC circuits must have a fixed cutoff frequency. In other words, it is impossible to change the cutoff frequency without directly replacing the passive components, and because replacing passive components requires manipulating the electronic substrate within the module, it is practically difficult to change the cutoff frequency.

[0099] However, since the target frequency increases proportionally with vehicle speed, the cutoff frequency of the high-pass filter needs to be adaptively changed in real time to adapt to the vehicle speed, thereby maintaining a high signal-to-noise ratio even when the vehicle is in motion.

[0100] If as Figure 10 and Figure 11If the fixed cutoff frequency in the high-pass filter used cannot be changed, noise filtering may not be properly performed when the vehicle accelerates or decelerates while driving, making it difficult to clearly detect the signal corresponding to the target frequency.

[0101] Therefore, this disclosure provides a noise filtering method that can maintain a high signal-to-noise ratio independent of vehicle speed by changing the passband in real time in response to vehicle speed, thereby providing a significant improvement in the safety of autonomous vehicles.

[0102] Here, the vehicle speed can be obtained based on information fed back from at least one of the vehicle's speedometer, GPS sensors, or a combination thereof.

[0103] For example, you can obtain the vehicle speed corresponding to the output value of the vehicle speedometer.

[0104] In another example, the vehicle's location, obtained via GPS sensors, is used to calculate the distance the vehicle has traveled, and the vehicle's speed can be calculated based on time and distance traveled.

[0105] Here, the passband can correspond to the range from the low cutoff frequency to the high cutoff frequency. The low cutoff frequency and the high cutoff frequency are set to correspond to the following signals, the amplitude of which is smaller than the amplitude of the signal at the center frequency by a preset reference amplitude.

[0106] For example, refer to Figure 15 A frequency whose signal amplitude is 3dB lower than the amplitude at the center frequency f0 can be set as the low cutoff frequency f. L and high cutoff frequency f H Here, the passband width, or frequency bandwidth B, can correspond to the value obtained by subtracting the low cutoff frequency from the high cutoff frequency.

[0107] Here, the passband can be reset with a setting cycle that takes into account vehicle speed settings.

[0108] For example, because the target frequency f v The target frequency f changes as the vehicle speed changes, so it needs to be changed again. v Set as Figure 15 The center frequency f0 is shown. Here, when the center frequency f0 changes, the low cutoff frequency f is set again. L and high cutoff frequency f H Therefore, the passband can also be changed.

[0109] Here, the following text will refer to Figure 16 Describe in detail the process of setting the passband according to vehicle speed.

[0110] Meanwhile, to respond to the frequent changes in vehicle speed, it may be necessary to reset the passband at a cycle of five times per second (every 0.2 seconds) or more. However, resetting the passband too frequently may impose limitations on the specifications of the ADC in the module and the design of the CPU used for frequency calculation and communication, which may increase the manufacturing cost of the module. Therefore, appropriately setting the passband reset cycle is an important point of this disclosure.

[0111] Here, the cycle can be calculated based on the emergency braking distance corresponding to the vehicle speed and the distance traveled within a preset time corresponding to the vehicle speed.

[0112] For example, the distance a vehicle travels during the passband reset cycle is an important factor in preventing accidents, so the passband reset cycle can be set by taking into account actual conditions, such as emergency braking distance.

[0113] Here, we will refer to later. Figure 17 Describe in detail the process of setting the passband reset cycle.

[0114] Here, noise filtering may include reducing the passband width when the amplitude difference between the signal corresponding to the target frequency and the signal corresponding to the noise frequency component is less than a preset reference difference.

[0115] For example, refer to Figure 2 It can be seen that when alternating magnetic patterns are applied to give the magnetic paint lane a spatial period of 10cm and when the vehicle is traveling at a speed of 30km / h, the target frequency is 83Hz.

[0116] In this case, when noise filtering is performed using a passband of 71–101 Hz, a signal corresponding to the target frequency (②) of 83 Hz is detected, and its amplitude is approximately 100 times that of the power noise signal corresponding to the frequency (①) of 60 Hz. Figure 12 As shown.

[0117] However, if the passband is set to 76–96 Hz to become narrower, the amplitude of the signal corresponding to the target frequency (②) of 83 Hz is approximately 1000 times the amplitude of the power noise signal corresponding to the frequency (①) of 60 Hz. Figure 13 As shown.

[0118] In other words, by setting the passband more precisely, the signal corresponding to the alternating magnetic signal can be identified more clearly after noise filtering.

[0119] In another example, it will be performed Figure 11 and Figure 14 The comparison is described in order to compare the result of performing noise filtering using a general high-pass filter with the result of performing noise filtering by precisely setting the passband according to this disclosure.

[0120] first, Figure 11 The results of filtering a signal using a high-pass filter with a cutoff frequency set to 80 Hz are shown. The signal was detected when the vehicle was traveling at 50 km / h and an alternating magnetic pattern was applied to make the spatial period of the magnetic paint lane 10 cm.

[0121] also, Figure 14 The results of filtering a signal using a passband of 132–153 Hz are shown. The signal was detected when the vehicle was traveling at 50 km / h and an alternating magnetic pattern was applied so that the spatial period of the magnetic paint lane was 10 cm.

[0122] In other words, under the same conditions, when noise filtering is performed using a more precisely configured passband according to this disclosure, the signal corresponding to the target frequency is detected more clearly than when noise filtering is performed using a general high-pass filter.

[0123] Therefore, in this disclosure, when it is determined that the signal corresponding to the target frequency is not clearly identified, the bandwidth of the passband is set narrower based on the center frequency of the passband, so that the signal corresponding to the target frequency can be detected more clearly.

[0124] Furthermore, in the method for generating vehicle control signals based on magnetic paint lanes according to embodiments of the present disclosure, in step S130, the operation of the vehicle is controlled based on a noise-removed magnetic induction signal.

[0125] For example, a noise-removed magnetic induction signal is frequency-converted, thereby generating a frequency-converted signal. This generated frequency-converted signal can then be used to control the operation of the vehicle. Here, the frequency-converted signal can be used as information for driving an autonomous vehicle.

[0126] By using the above-described method of generating vehicle control signals based on magnetic paint lanes, magnetic signals generated from magnetic paint lanes with alternating magnetic patterns can be clearly detected, thereby enabling safe control of vehicle operation.

[0127] Furthermore, for autonomous vehicle systems that use magnetic signals generated from the magnetic paint lane to drive autonomous vehicles, noise from other vehicles, power transmission lines, autonomous vehicle vibrations, etc., is eliminated, thereby reducing the occurrence rate of autonomous vehicle failures and enabling their safe operation.

[0128] Furthermore, the cutoff frequency value in the frequency filter is adaptively changed in real time to adapt to the vehicle's speed, which changes frequently during driving, thereby improving the signal-to-noise ratio and the safety of autonomous vehicles.

[0129] Figure 16This is a flowchart illustrating in detail the process of setting the passband according to embodiments of the present disclosure.

[0130] refer to Figure 16 In the process of setting the passband according to the embodiments of this disclosure, firstly, the center frequency fp0 and the low cutoff frequency fp of the passband can be checked in step S1610. L High cutoff frequency fp H The current setting value of frequency bandwidth B.

[0131] Subsequently, steps from S1615 to S1650 can be repeated to reset the passband every 0.2 seconds (200 milliseconds, which is the passband reset cycle).

[0132] In the loop including steps from S1615 to S1650, firstly, in step S1615, the target frequency f set according to the current vehicle speed is checked. v Is it the same as the center frequency fp0, and when the target frequency f v If the center frequency fp0 is not the same as the target frequency f, the value of the center frequency fp0 can be set at step S1620 to match the target frequency f. v The value of .

[0133] Subsequently, in step S1630, the low cutoff frequency fp can be set. L and high cutoff frequency fp H This corresponds to a signal whose amplitude is smaller than the amplitude of a signal with a center frequency fp0 by a preset reference amplitude.

[0134] For example, in Figure 16 In step S1630, the low cutoff frequency fp L and high cutoff frequency fp H It can be set to correspond to a signal whose amplitude is reduced to 50% of the signal amplitude at the center frequency fp0, that is, a signal whose amplitude is 3dB lower than the signal amplitude at the center frequency fp0.

[0135] As described above, the low cutoff frequency fp is reset based on the center frequency fp0. L and high cutoff frequency fp H This allows the low cutoff frequency fp to be reset. L to the high cutoff frequency fp of the reset H The range is set to passband.

[0136] Here, the passband frequency bandwidth B can be changed to correspond to the reset low cutoff frequency fp. L and the high cutoff frequency fp of the reset H .

[0137] Subsequently, within the loop, after waiting for 0.2 seconds (200 milliseconds, which is the passband reset period), the vehicle's current speed v is checked at step S1640, and the target frequency f corresponding to the vehicle's current speed is calculated at step S1650. v And the steps starting from step S1615 can be repeated.

[0138] Furthermore, when the target frequency f is determined in step S1615 v When the center frequency fp0 is the same, it is determined that the passband does not need to be reset, and the steps starting from step S1640 can be repeated after 0.2 seconds (200 milliseconds, which is the period for passband reset).

[0139] As described above, this is repeated during each passband reset cycle. Figure 16 The loop in the loop allows for setting a passband based on vehicle speed to perform effective noise filtering and clearly detect the target frequency.

[0140] Figure 17 This is a flowchart illustrating in detail the process for setting the cycle of passband reset according to embodiments of the present disclosure.

[0141] refer to Figure 17 In the process of setting the passband reset period according to an embodiment of the present disclosure, firstly, the currently set passband reset period (repetition period) can be checked in step S1710.

[0142] Subsequently, while the vehicle is in motion, steps S1720 to S1740 are repeated, and the passband reset cycle is calculated again. Here, when the calculated value changes, the cycle can be reset to the changed value.

[0143] In the loop including steps from S1720 to S1740, firstly, the vehicle speed v is checked in step S1720, and it can be checked in step S1725 whether the vehicle speed has changed.

[0144] When a change in vehicle speed is determined in step S1725, the emergency braking distance BD corresponding to the changed current speed can be calculated in step S1730. v As shown in equation (2):

[0145]

[0146] Subsequently, in step S1730, the emergency braking distance is determined to have changed by comparing the calculated emergency braking distance corresponding to the changed current speed with the emergency braking distance before the speed change. If it is determined that the emergency braking distance has changed, the passband reset cycle can be set again in step S1740.

[0147] For example, when a vehicle is traveling at a speed of 30 km / h, it travels 8 meters per second. Here, according to equation (2), the emergency braking distance is calculated to be 4.5 m, but it can vary depending on the road surface and the environment around the vehicle.

[0148] Therefore, for safe driving, the passband must be reset before the vehicle has traveled at least 3.5m, and the passband reset cycle can be set to 0.4 seconds or less.

[0149] However, considering the actual braking distance (which is known to be twice the emergency braking distance), the passband reset cycle can be set to 0.2 seconds or less, thereby reducing the risk of accidents during emergency braking of the vehicle.

[0150] When the passband reset cycle is set to 0.1 seconds, the passband is reset every time the vehicle travels 0.8 meters, which can greatly improve the safety of autonomous vehicles.

[0151] Furthermore, when it is determined in step S1725 that the vehicle speed has not changed significantly, or when it is determined in step S1735 that the emergency braking distance has not changed, the steps starting from step S1720 can be repeated.

[0152] For example, in step S1725, a preset range for vehicle speed variation is established, and when the vehicle speed exceeds this range, it can be determined that the vehicle speed has changed. Furthermore, in step S1735, a preset range for emergency braking distance variation is established, and when the emergency braking distance exceeds this range, it can be determined that the emergency braking distance has changed.

[0153] Figure 18 This is a block diagram illustrating an apparatus for generating vehicle control signals based on a magnetic paint lane, according to an embodiment of the present disclosure.

[0154] Here, the apparatus for generating vehicle control signals based on magnetic paint lanes according to embodiments of the present disclosure can operate in conjunction with magnetic sensors disposed in the vehicle, or can operate by including magnetic sensors.

[0155] refer to Figure 18 An apparatus for generating vehicle control signals based on a magnetic paint lane, according to embodiments of the present disclosure, may include a communication unit 1810, a processor 1820, and a memory 1830.

[0156] The communication unit 1810 can be used to send and receive information required for generating vehicle control signals based on the magnetic paint lane via a communication network. Here, the network provides a path for data transfer between devices and can be conceptually understood to include both currently used networks and networks yet to be developed.

[0157] For example, the network can be an IP network (which provides services for sending and receiving large amounts of data and seamless data services via the Internet Protocol (IP)), an all-IP network (which is an IP network structure that integrates different networks based on IP), etc., and can be configured as a wired network, a wireless broadband (WiBro) network, a 3G mobile communication network including WCDMA, a 3.5G mobile communication network including High Speed ​​Downlink Packet Access (HSDPA) network and LTE network, a 4G mobile communication network including Advanced LTE, a satellite communication network, and a Wi-Fi network, or one or more combinations thereof.

[0158] Furthermore, the network can be any of the following: a wired / wireless local area communication network for providing communication between various data devices within a limited area; a mobile communication network for providing communication between mobile devices or between mobile devices and their external systems; a satellite communication network for providing communication between earth stations using satellites; and a wired / wireless communication network, or a combination of two or more of these. At the same time, the network's transmission protocol standard is not limited to existing transmission protocol standards, but can include all transmission protocol standards to be developed in the future.

[0159] The processor 1820 generates a magnetic induction signal corresponding to the alternating magnetic pattern from the magnetic paint lane.

[0160] Here, by applying alternating magnetic patterns, the magnetic paint lane can be generated as a spatial period corresponding to a length greater than 0 cm and equal to or less than 25 cm.

[0161] In addition, the processor 1820 performs noise filtering on the magnetic induction signal to generate a noise-free magnetic induction signal.

[0162] Here, noise filtering may include filtering out low-frequency signals with frequencies below a target frequency, which is detected by taking into account the spatial period of the alternating magnetic pattern and the speed of the vehicle.

[0163] Here, noise filtering may include filtering out a first noise frequency component corresponding to the state where the vehicle is not moving, and a second noise frequency component corresponding to the state where the vehicle's speed change is less than a preset reference level.

[0164] Here, noise filtering may include: changing the characteristics of the filter to correspond to the target frequency based on vehicle speed detection.

[0165] Here, the vehicle speed can be obtained based on information fed back from at least one of the vehicle's speedometer, GPS sensors, or combinations thereof.

[0166] Here, noise filtering may include: setting a passband, the center frequency of which is set to a target frequency; and filtering out noise frequency components not included in the passband.

[0167] Here, the passband can correspond to the range from the low cutoff frequency to the high cutoff frequency. The low cutoff frequency and the high cutoff frequency are set to correspond to the following signals, the amplitude of which is smaller than the amplitude of the signal at the center frequency by a preset reference amplitude.

[0168] Here, the passband can be reset using a setting cycle that takes into account vehicle speed.

[0169] Here, the setting cycle can be calculated based on the emergency braking distance corresponding to the vehicle speed and the driving distance corresponding to the vehicle speed for a preset time.

[0170] Here, noise filtering may include reducing the passband width when the amplitude difference between the signal corresponding to the target frequency and the signal corresponding to the noise frequency component is less than a preset reference difference.

[0171] Moreover, the processor 1820 controls the vehicle's operation based on a noise-removed magnetic induction signal.

[0172] The memory 1830 stores a low-pass filter and an adaptive frequency filter.

[0173] Furthermore, the memory 1830 stores various information generated in the aforementioned apparatus for generating vehicle control signals based on magnetic paint lanes according to embodiments of the present disclosure.

[0174] According to an embodiment, the memory 1830 can be separated from the means for generating vehicle control signals based on the magnetic paint lane, and can support the function for generating vehicle control signals based on the magnetic paint lane. Here, the memory 1830 can operate as a separate mass storage device, and can include control functions for performing the operation.

[0175] Meanwhile, the means for generating vehicle control signals based on the magnetic paint lane includes a memory installed therein, in which information can be stored. In one embodiment, the memory is a computer-readable medium. In another embodiment, the memory may be a volatile memory cell, and in yet another embodiment, the memory may be a non-volatile memory cell. In another embodiment, the storage device is a computer-readable recording medium. In various embodiments, the storage device may include, for example, a hard disk drive, an optical disk drive, or any other type of mass storage device.

[0176] Using the aforementioned device for generating vehicle control signals based on magnetic paint lanes, magnetic signals generated from magnetic paint lanes with alternating magnetic patterns can be clearly detected, thereby enabling safe vehicle control.

[0177] Furthermore, in autonomous vehicle systems that use magnetic signals generated from magnetic paint lanes to drive autonomous vehicles, noise caused by other vehicles, power transmission lines, vibrations of the autonomous vehicle, etc., is eliminated, thereby reducing the failures of the autonomous vehicle and enabling its safe operation.

[0178] Furthermore, the cutoff frequency value in the frequency filter is adaptively changed in real time to adapt to the vehicle's speed, which changes frequently during driving, thereby improving the signal-to-noise ratio and safety of autonomous vehicles.

[0179] According to this disclosure, magnetic signals generated from a magnetic paint lane with an alternating magnetic pattern can be clearly detected, thereby enabling safe vehicle control.

[0180] Furthermore, in an autonomous vehicle system that uses magnetic signals generated from a magnetic paint lane to drive an autonomous vehicle, this disclosure can reduce autonomous vehicle malfunctions by eliminating noise caused by other vehicles, power transmission lines, and autonomous vehicle vibrations, thereby enabling safe operation of the autonomous vehicle.

[0181] Furthermore, this disclosure can improve the signal-to-noise ratio and safety of autonomous vehicles by adaptively changing the cutoff frequency value in the frequency filter in real time to adapt to the frequently changing vehicle speed during driving.

[0182] The effects of this embodiment are not limited to those described above, and those skilled in the art can clearly understand other effects not mentioned based on the appended claims.

[0183] As described above, the method and apparatus for generating vehicle control signals based on magnetic paint lanes according to this disclosure are not limited to the configuration and operation of the above embodiments, but all or some embodiments can be selectively combined and configured, and thus these embodiments can be modified in various ways.

Claims

1. A method for generating vehicle control signals based on magnetic paint lanes, comprising: Generate a magnetic induction signal corresponding to the alternating magnetic pattern from the magnetic paint lane; The magnetic induction signal is subjected to noise filtering to generate a noise-removed magnetic induction signal; as well as The vehicle operation is controlled based on the noise-removed magnetic induction signal. The noise filtering includes: changing the characteristics of the filter to correspond to a target frequency detected based on the vehicle's speed; setting a passband, the center frequency of which is set to the target frequency; filtering out noise frequency components not included in the passband; and reducing the width of the passband when the amplitude difference between the signal corresponding to the target frequency and the signal corresponding to the noise frequency component is less than a preset reference difference.

2. The method according to claim 1, wherein, By applying the alternating magnetic pattern, the magnetic paint lane is generated with a spatial period of length greater than 0 cm and equal to or less than 25 cm.

3. The method according to claim 2, wherein, The noise filtering includes filtering out low-frequency signals with frequencies below a target frequency, which is detected by taking into account the spatial period of the alternating magnetic pattern and the speed of the vehicle.

4. The method according to claim 3, wherein, The noise filtering includes filtering out a first noise frequency component corresponding to the state where the vehicle is not driven and a second noise frequency component corresponding to the state where the vehicle's speed change is less than a preset reference level.

5. The method according to claim 1, wherein, The speed of the vehicle is obtained based on information fed back from at least one of the vehicle's speedometer, GPS sensors, or combinations thereof.

6. The method according to claim 1, wherein, The passband's setting cycle, which takes into account the vehicle's speed, is reset.

7. The method according to claim 6, wherein, The set period is calculated based on the emergency braking distance corresponding to the vehicle's speed and the driving distance for a preset time corresponding to the vehicle's speed.

8. The method according to claim 1, wherein, The passband corresponds to the range from a low cutoff frequency to a high cutoff frequency, and the low cutoff frequency and the high cutoff frequency are set to correspond to a signal whose amplitude is smaller than the amplitude of the signal at the center frequency by a preset reference amplitude.

9. An apparatus for generating vehicle control signals based on a magnetic paint lane, comprising: The processor is configured to generate a magnetic induction signal corresponding to an alternating magnetic pattern from a magnetic paint lane, perform noise filtering on the magnetic induction signal to generate a noise-removed magnetic induction signal, and control the operation of the vehicle based on the noise-removed magnetic induction signal. as well as A memory for storing the magnetic induction signal. The noise filtering includes: changing the characteristics of the filter to correspond to a target frequency detected based on the vehicle's speed; setting a passband, the center frequency of which is set to the target frequency; filtering out noise frequency components not included in the passband; and reducing the width of the passband when the amplitude difference between the signal corresponding to the target frequency and the signal corresponding to the noise frequency component is less than a preset reference difference.

10. The apparatus of claim 9, wherein by applying the alternating magnetic pattern, the magnetic paint lane is generated to have a spatial period with a length greater than 0 cm and equal to or less than 25 cm.

11. The apparatus of claim 10, wherein the noise filtering comprises: Low-frequency signals with frequencies below a target frequency are filtered out, the target frequency being detected by taking into account the spatial period of the alternating magnetic pattern and the speed of the vehicle.

12. The apparatus according to claim 11, wherein, The noise filtering includes filtering out a first noise frequency component corresponding to the state where the vehicle is not driven and a second noise frequency component corresponding to the state where the vehicle's speed change is less than a preset reference level.

13. The apparatus according to claim 9, wherein, The speed of the vehicle is obtained based on information fed back from at least one of the vehicle's speedometer, GPS sensors, or combinations thereof.

14. The apparatus according to claim 9, wherein, The passband's setting cycle, which takes into account the vehicle's speed, is reset.

15. The apparatus according to claim 14, wherein, The set period is calculated based on the emergency braking distance corresponding to the vehicle's speed and the driving distance for a preset time corresponding to the vehicle's speed.

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