Radar sensing-based intelligent on-demand lighting control system

Abstract

The present invention belongs to the technical field of lighting, and specifically relates to a radar sensing-based intelligent on-demand lighting control system, comprising: radar sensor modules and single lamp controllers, the radar sensor modules and the single lamp controllers being mounted on a lamp pole of each street lamp by means of mounting housings. The present invention increases brightness in advance in case of the presence of people or vehicles and dims light immediately in case of the absence of people or vehicles; by means of a scientific and reasonable software algorithm and on the basis of a driving speed, automatically adjusts the number of lamps turned on in advance; and, according to road traffic flows in different time periods, automatically adjusts the illumination brightness of a whole street, thereby achieving an energy-saving control purpose for adaptive and dynamic on-demand lighting.

Description

An intelligent on-demand lighting control system based on radar sensing Technical Field

[0001] The present invention belongs to the field of lighting technology, and in particular relates to an intelligent on-demand lighting control system based on radar sensing. Background Art

[0002] With the promotion of smart city construction, more and more cities are updating and renovating smart street lights. In areas where intelligent single-lamp lighting control systems are installed, street lights are dimmed according to different time periods to reduce energy consumption. However, this is only a timed adjustment and cannot achieve adaptive dynamic dimming for different roads and time periods based on pedestrian and vehicle traffic. In particular, lighting on low-traffic sections in the second half of the night requires precise adjustment to reduce energy waste.

[0003] Therefore, in recent years, attempts have been made to use radar as a road lighting sensor to implement dimming control. However, due to the complexity of urban road environments (such as rain, fog, mosquitoes, and wind) in different seasons, climates, road conditions, and application scenarios, using radar as a sensor to obtain real-time dynamic information on urban road pavement (pedestrians and vehicles) for energy-saving control of street lights faces two major challenges:

[0004] First, achieving accurate radar detection of pedestrian / vehicle information and filtering out false alarms of non-pedestrian / vehicle traffic on the road requires high-performance hardware and components. This directly leads to excessively high equipment costs. The hardware investment is not proportional to the energy-saving benefits, and this has hindered market penetration.

[0005] Secondly, the traditional smart street light single-lamp controller in the existing technology does not have fast-rate (millisecond-level) communication transmission, and cannot quickly transmit the street light radar sensor signal to the multiple lamp poles in front of the vehicle to realize early lighting. In addition, since the existing traditional smart street light single-lamp controller does not have edge computing function, it cannot perform information edge computing processing based on the pedestrian / vehicle information status obtained by the radar (such as driving speed, vehicle flow and pedestrian flow, etc.), and autonomously adjust the lighting dimming control strategy. Summary of the Invention

[0006] Based on the problems mentioned in the above background technology, the present invention provides an intelligent on-demand lighting control system based on radar sensing.

[0007] The technical solution adopted by the present invention is as follows: an intelligent on-demand lighting control system based on radar sensing, including a radar sensor module and a single-lamp controller, wherein the radar sensor module and the single-lamp controller are arranged on the lamp pole or lamp of each street lamp; the radar sensor module transmits a signal through a transmitting antenna to collect road surface related motion information, and receives a time-delayed signal through a receiving antenna, mixes the time-delayed signal with the transmitted signal to generate an intermediate frequency signal containing road surface related motion information, converts the intermediate frequency signal into a digital signal, and outputs the speed information in the motion information to the single-lamp controller through detection frequency analysis; a street lamp is designated as a master street lamp, and the single-lamp controller is used to receive and process the information obtained by the corresponding radar, and control the master street lamp to illuminate within the continuous lighting time, and at the same time send a lighting request to the single-lamp controller of the controlled street lamp located in the direction of the road surface related motion information, wherein the lighting request includes the identification of the master street lamp, the identification of the controlled street lamp, and the continuous lighting time.

[0008] Furthermore, the delayed signal s_t=exp(2*pi*f*(t-tao)) is mixed with the transmitted signal s_r=exp(2*pi*f*t) to obtain the intermediate frequency signal:

[0009] s=exp(-2*pi*f*tao)=exp(-2*pi*f*(2*(R-Vt) / c))=exp(-2*pi*f*(2*(R-Vt / 2) / c))=exp(-2*pi*f*(2*(R-Vt / 2) / c))=exp(2*pi*(f*V / c)*t-4*pi*f*R / c), where f is frequency, t is time, pi is pi, R is the initial distance between the radar and the target, V is acceleration, and c is the speed of light.

[0010] Furthermore, the digital signal s(n)=epx(2*PI*f*n / m)(n=1,...,m) is filtered to obtain

[0011] Written in matrix form 1

[0012] Convert the matrix form 1 calculation process into circular convolution

[0013] Construct a new sequence S1 = [s(1),…,s(m),0,…,0]; S2 = [0,…0,s(1),…,s(m)];

[0014] That is, m zeros are added to the back of the original data to construct S1, and m zeros are added to the front of the original data to construct S2; after the circular convolution of S1 and S2, y can be obtained;

[0015] Calculation process:

[0016] 1: Perform a 2048-point FFT on the s1 sequence to obtain S1; 2: Perform a 2048-point FFT on the s2 sequence to obtain S2; 3: Multiply S1 by the conjugate of S2 to obtain S3; 4: Perform a 2048-point IFFT on S3 to obtain s; 5: Take s(512)…s(1024) to obtain y; 6: Perform FFT on y to obtain the spectrum s(w); 7: Search for the maximum value of s(w) and use CFAR detection to identify motion information.

[0017] Furthermore, the speed information is used to obtain the Doppler frequency F through the sampling period T, where F=f*V' / c, and the speed V'=F*c / f.

[0018] Furthermore, the master streetlight increases the brightness during the continuous lighting time, and obtains the minimum time for continuous lighting adjustment according to the speed information and the lamp distance: assuming that the continuous lighting adjustment time is T0, then: T0≥d / V', where d is the lamp distance, d=t_dc / 2.

[0019] Furthermore, the single-lamp controller on the master street lamp sends a lighting adjustment or light-on request to the n consecutive controlled street lamps located in front of the motion information, specifically including: obtaining the corresponding identification of the n consecutive controlled street lamps located in front of the motion information of the master street lamp; forming a request data packet with the identification corresponding to each controlled street lamp, the identification of the master street lamp and the continuous lighting adjustment time; sending the request data packet to the single-lamp controller of the controlled street lamp; wherein n>3.

[0020] Furthermore, the single-lamp controller on the master street lamp controls the controlled street lamps behind the motion information to be brightened. The number of controlled street lamps is m, and the continuous lighting brightening time T satisfies T=m*T0, m≥1.

[0021] Furthermore, the street lamp is powered by a digital power supply UART. After receiving the motion information, the single lamp controller controls the digital power supply UART to realize the brightness adjustment of the street lamp and the switching control of the lamp.

[0022] Beneficial effects of the present invention:

[0023] Through radar sensors, accurate data on the dynamic movement of pedestrians and vehicles on urban road lighting lamps is obtained. The single-lamp controller implements a reasonable street lamp dimming control strategy to achieve early brightness when there are people and cars, and immediate dimming of lights when there are no people and cars. At the same time, the number of lights that are turned on in advance and the length of delayed lighting are automatically adjusted according to the driving speed. The traffic flow radar sensor can detect road traffic flow data to automatically adjust the lighting brightness of the entire road at different time periods, realizing the purpose of adaptive dynamic on-demand lighting energy-saving control. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0025] FIG1 is a flowchart of the operation of the radar sensor module of the present invention;

[0026] FIG2 is a schematic diagram of the application of the radar, single-lamp controller and concentrator of the present invention;

[0027] FIG3 is a circuit diagram of a main control unit of a single lamp controller according to the present invention;

[0028] FIG4 is a diagram showing the communication interface between the single-lamp controller and the radar sensor module of the present invention;

[0029] FIG5 is a diagram of the UART communication interface between the single lamp controller and the digital power supply of the present invention;

[0030] FIG6 is a circuit diagram of a digital power supply UART power supply and communication application according to the present invention;

[0031] FIG7 is a master-slave single-line UART communication circuit diagram of a single-lamp controller according to the present invention;

[0032] FIG8 is a schematic diagram of an on-demand road lighting application according to the present invention;

[0033] FIG9 is a schematic diagram of the structure of a lighting system controlled by a single lamp controller according to the present invention; DETAILED DESCRIPTION

[0034] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and drawings. The contents mentioned in the embodiments are not intended to limit the present invention.

[0035] The road surface-related motion information described below includes both sidewalks and roadways, and the moving body also describes cars or people, achieving the effect of lighting control and dimming of sidewalks and roadways separately: For the convenience of description, the default dimming process of the master street light and the controlled street light is that the radar sensor module receives the motion information and transmits it to the corresponding single-lamp controller with edge computing, which controls the digital drive power supply to power the street light to achieve street light brightness adjustment and switch light control.

[0036] As shown in Figures 8-9, an intelligent on-demand lighting control system based on radar sensing includes a radar sensor module and a single-lamp controller. The radar sensor module and the single-lamp controller are set on the lamp pole or lamp of each street lamp, making one street lamp a master street lamp. The single-lamp controller is used to receive and process the information obtained by the corresponding radar. According to the information, the single-lamp controller controls the master street lamp to increase the lighting brightness within the continuous lighting time, and at the same time sends a lighting request to the single-lamp controller of the controlled street lamp located in the driving direction of the road surface-related motion information. The lighting request includes the identification of the master street lamp, the identification of the controlled street lamp and the continuous lighting adjustment time.

[0037] As shown in Figure 3, the single-lamp controller simultaneously obtains motion information data such as the direction and speed of people / vehicles on the road surface sent by the radar sensor. It automatically calculates how many lights should be sent to turn on or dim the lights in front of the pedestrian / vehicle, and automatically calculates the delay time for dimming or turning off the lights after the person / vehicle passes. When the single-lamp controller of the controlled street lamp receives the lighting on / off or dimming request, it responds immediately and quickly (within 200ms) to turn on or brighten the light:

[0038] For example, when street light controller No. 5 detects a vehicle's motion from its radar sensor module, it immediately turns its own street light on and simultaneously broadcasts a command to brighten lights 6, 7, 8, 9, and 10 ahead of the vehicle. This continues for a configurable period of time. If no new command is received, the lights automatically dim. If a new command is received during the on-time period, the duration is reset and recalculated. This achieves on-demand dynamic automatic lighting control, with the lights turning on when a vehicle approaches and dimming when a vehicle leaves, achieving significant energy savings.

[0039] After obtaining relevant movement information of the road surface, the street lights within the travel range can be turned on to provide lighting. The corresponding street lights can be controlled to illuminate within a certain sight range in front of people and vehicles to ensure safety. In places where there is no driving or sight range, no lighting or lower lighting brightness can be provided, thereby achieving the purpose of energy saving. At the same time, the number of lights that are turned on in advance can be automatically adjusted according to the driving speed, and the lighting brightness of the entire road can be automatically adjusted according to the road traffic flow at different time periods, realizing the purpose of adaptive dynamic on-demand lighting energy-saving control.

[0040] In this embodiment:

[0041] Lamp poles are equipped with radar sensor modules and single-lamp controllers on both sides of the carriageway and sidewalk, so that the radar sensor modules can collect movement information of the sidewalk and carriageway respectively. In this embodiment, the radar sensor module adopts millimeter-wave radar or microwave radar, both of which are equipped with MCU chips with edge computing functions, and are powered by DC through a digital drive power supply. The advantage is that there is no AC power in the cavity of the single-lamp control device, which does not interfere with the communication signal. The device is small in size, beautiful in appearance, light in weight, low in interference and high in spatial resolution, and can directly measure distance and speed information and detect the inclination angle of the lamp pole; the radar sensor module transmits information to the single-lamp control module through communication methods such as RS485, TTL or IOI.

[0042] The single-lamp controller is a single-lamp control module with edge computing. It can act as both a master and a slave. The single-lamp controller has a variety of communication interfaces (RS485, TTL, and IOI) and can receive, forward, and calculate data signals from radar and other sensors.

[0043] As shown in Figures 1 and 4, the radar sensor module transmits signals through the transmitting antenna to collect road-related motion information, and receives the delayed signal through the receiving antenna. The delayed signal is mixed with the transmitted signal to generate an intermediate frequency signal containing road-related motion information. After the intermediate frequency signal is converted into a digital signal, the speed information in the motion information is output to the single-lamp controller through detection frequency analysis.

[0044] The unique algorithm of frequency mixing and detection frequency analysis can solve the high cost problem of radar for street light control and the stability problem of false alarm signal.

[0045] As a preferred solution, the delay signal s_t=exp(2*pi*f*(t-tao)) is mixed with the transmission signal s_r=exp(2*pi*f*t) to obtain the intermediate frequency signal

[0046] s=exp(-2*pi*f*tao)=exp(-2*pi*f*(2*(R-Vt) / c))=exp(-2*pi*f*(2*(R-Vt / 2) / c))=exp(-2*pi*f*(2*(R-Vt / 2) / c))=exp(2*pi*(f*V / c)*t-4*pi*f*R / c), where f is frequency, t is time, pi is pi, R is the initial distance between the radar and the target, V is acceleration, and c is the speed of light.

[0047] The mixed signal s=exp(2*pi*(f*V / c)*t-4*pi*f*R / c) is quantized by the ADC and converted into a digital signal s(n).

[0048] As a preferred solution, the digital signal s(n)=epx(2*PI*f*n / m)(n=1,...,m) is filtered to obtain

[0049] Written in matrix form 1

[0050] Analyze the first one

[0051] The noise is white noise background, the signal to noise ratio is improved times, when m=1024 points, the signal-to-noise ratio is increased by 30.1dB, which greatly increases the detection distance of the radar; in order to improve the real-time performance of the calculation, the matrix form 1 calculation process is converted into a circular convolution

[0052] Construct a new sequence S1 = [s(1),…,s(m),0,…,0]; S2 = [0,…0,s(1),…,s(m)];

[0053] That is, m zeros are added to the back of the original data to construct S1, and m zeros are added to the front of the original data to construct S2; after the circular convolution of S1 and S2, y can be obtained;

[0054] Calculation process:

[0055] 1: Perform a 2048-point FFT on the s1 sequence to obtain S1; 2: Perform a 2048-point FFT on the s2 sequence to obtain S2; 3: Multiply S1 by the conjugate of S2 to obtain S3; 4: Perform a 2048-point IFFT on S3 to obtain s; 5: Take s(512)…s(1024) to obtain y; 6: Perform FFT on y to obtain the spectrum s(w); 7: Search for the maximum value of s(w) and use CFAR detection to identify motion information.

[0056] Through scientific algorithm design, the signal-to-noise ratio is effectively improved, the stability of the radar sensor module is ensured, the problem of false alarm information is effectively reduced, the impact of noise on the signal is reduced, the measurement results are more accurate, and the detection accuracy of the radar sensor module is improved.

[0057] As a preferred solution, the speed information is used to obtain the Doppler frequency F through a sampling period T, where F=f*V' / c, and the speed V'=F*c / f.

[0058] As a preferred solution, the master streetlight increases its brightness during the continuous illumination period. The minimum duration for continuous illumination is determined based on speed information and lamp spacing. Assuming the continuous illumination period is T0, the following applies: T0 ≥ d / V', where d is the lamp spacing and d = t_dc / 2. T0 is only a theoretical minimum illumination period. In actual road traffic applications, the illumination period should be configured to improve overall applicability.

[0059] As a preferred solution, the single-lamp controller on the master street lamp sends a lighting adjustment or lighting turn-on request to the n consecutive controlled street lamps located in front of the motion information, specifically including: obtaining the corresponding identifications of the n consecutive controlled street lamps located in front of the motion information of the master street lamp; forming a request data packet with the identification corresponding to each controlled street lamp, the identification of the master street lamp and the continuous lighting adjustment time; and sending the request data packet to the single-lamp controller of the controlled street lamp; wherein n>3.

[0060] The most important driving parameter of a vehicle is its speed. The distance between streetlights determines the distance of continuous streetlights. Therefore, the distance range of streetlight illumination plays a key role in ensuring safe driving of vehicles at a certain speed. Generally speaking, the distance between streetlights on a certain section of road is constant, so the distance of continuous streetlights is related to the number of streetlights. At least, the faster the speed, the better the number of continuously illuminated streetlights should be. The specific number of settings can be adjusted according to local traffic conditions.

[0061] As a preferred solution, the single-lamp controller on the master street lamp controls the controlled street lamps behind the motion information to be brightened. The number of controlled street lamps is m, and the continuous lighting brightening time T satisfies T=m*T0, m≥1.

[0062] When considering the driving situation, sometimes the driver needs to observe the situation behind through the reflector or rearview mirror, so it is best to provide at least one street light behind the vehicle for lighting; at the same time, the sidewalk is set up in this way also considering that pedestrians walk at a slower speed, providing better lighting safety for pedestrians.

[0063] In summary, when a moving object enters the detection range, in addition to the main control streetlight and the two controlled streetlights behind it, which need to be turned on, the controlled streetlight in front will illuminate according to the preset continuous lighting time after receiving the request. After the time is up, it will return to its initial state (off or dimmed). The main control streetlight and the controlled streetlight behind it are not affected by the continuous lighting time. The main control streetlight and the controlled streetlight behind it corresponding to the position of the moving object must remain on.

[0064] For example, when the vehicle is currently located at the second street light, a street light behind the vehicle needs to be turned on. When the vehicle is located at the third street light, the first street light needs to be dimmed or turned off, and the second street light needs to be brightened.

[0065] It should be noted that when a vehicle travels from the current master street light to the next controlled street light, the controlled street light can also detect the vehicle's driving parameters. At this time, the next controlled street light becomes the master street light. When the speed does not change significantly, the controlled street light in front of the vehicle also needs to be lit. At this time, if the controlled street light in front of the vehicle is already in the lit state, the duration will be reset after receiving the command again, and the duration of the adjustment will be recalculated; the street light behind is no longer a controlled street light, and if it does not receive the command, it will be restored to the initial state.

[0066] As shown in Figure 2, after adding the concentrator, the entire road can be dimmed according to traffic flow. The specific process can be as follows: the single-lamp controller located in the main control street light receives the real-time signal uploaded by the radar sensor during operation to the concentrator. The concentrator sends dimming instructions to the single-lamp controllers of the entire road in the set area to automatically adjust the brightness of the lights.

[0067] In addition to the HPLC broadband carrier communication mentioned in Figure 2, other control communication methods can also be adapted, such as Wi-sun, and other wireless communication methods and RS485 wired communication methods. At least it can broadcast to controlled street lights within a range of hundreds or thousands of meters, and can achieve millisecond-level real-time transmission control.

[0068] As a preferred solution, the street lamp is powered by a digital power supply UART. After receiving the motion information, the single lamp controller controls the digital power supply UART to realize the brightness adjustment of the street lamp and the switching control of the lamp.

[0069] As shown in Figures 6-7, the digital driver and the single-lamp controller provide DC power and perform master-slave, single-line, bidirectional UART communication. As shown in Figure 5, the single-lamp control module can obtain power supply electrical parameter data from the digital power supply and send commands to the digital power supply for light on / off and dimming. Furthermore, as shown in Figures 4-5, the communication interface can also receive control signals from a radar sensor module. The radar sensor module communicates with the single-lamp controller using various communication methods, including TTL, IOI, and RS485 for dimming communication. After receiving the radar information, the single-lamp controller communicates with the digital driver via master-slave, single-line UART communication to control the streetlight module's 0-10V dimming or turn it off, achieving streetlight lighting adjustment. The digital driver offers a high degree of flexibility and programmability, allowing users to adjust the output current as needed, thereby varying the brightness of the LED lamp.

[0070] The present invention has been described in detail above. The description of the specific embodiments is intended only to facilitate understanding of the method and core concept of the present invention. It should be noted that those skilled in the art may make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An intelligent on-demand lighting control system based on radar sensing, characterized in that: It includes a radar sensor module and a single - lamp controller, and the radar sensor module and the single - lamp controller are arranged on the lamp post or the lamp of each street lamp; The radar sensor module emits signals through a transmitting antenna, collects road - related motion information, and receives delay signals through a receiving antenna. The delay signals are mixed with the transmitted signals to generate intermediate - frequency signals containing road - related motion information. After the intermediate - frequency signals are converted into digital signals, the speed information in the motion information is output to the single - lamp controller through detecting frequency analysis; Let one street lamp be the main - controlled street lamp. The single - lamp controller is used to receive and process the information obtained by the corresponding radar sensor module, and control the main - controlled street lamp to illuminate during the continuous lighting time. At the same time, it sends a lighting request to the single - lamp controllers of the controlled street lamps located in the driving direction of the road - related motion information. The lighting request includes the identification of the main - controlled street lamp, the identification of the controlled street lamp, and the continuous lighting time; The delay signal \(s_t=\exp(2\pi f(t - \tau))\) is mixed with the transmitted signal \(s_r=\exp(2\pi ft)\) to obtain the intermediate - frequency signal: \(s=\exp(-2\pi f\tau)=\exp(-2\pi f(2(R - Vt) / c))=\exp(-2\pi f(2(R - Vt / 2) / c))=\) \(\exp(-2\pi f(2(R - Vt / 2) / c))=\exp(2\pi(fV / c)t - 4\pi fR / c)\); where \(f\) is the frequency, \(t\) is the time, \(\pi\) is the pi, \(R\) is the initial distance from the radar sensor module to the target, \(V\) is the acceleration, and \(c\) is the speed of light; The digital signal s(n) = epx(2*PI*f*n / m) (n = 1, …, m) is filtered to obtain Written in matrix form 1 Convert the calculation process of matrix form 1 into circular convolution Construct a new sequence \(S1 = [s(1),\cdots,s(m),0,\cdots,0]\); \(S2 = [0,\cdots,0,s(1),\cdots,s(m)]\); That is, \(m\) zeros are added to the back of the original data to construct \(S1\), and \(m\) zeros are added to the front of the original data to construct \(S2\); After the circular convolution of \(S1\) and \(S2\), \(y\) can be obtained; Calculation process: One: The \(s1\) sequence is subjected to 2048 - point FFT to obtain \(S1\); Two: The \(s2\) sequence is subjected to 2048 - point FFT to obtain \(S2\); Three: \(S1\) multiplies the conjugate of \(S2\) to obtain \(S3\); Four: \(S3\) is subjected to 2048 - point IFFT to obtain \(s\); Five: Take \(s(512)\cdots s(1024)\) to obtain \(y\); Six: \(y\) is subjected to FFT to obtain the spectrum \(s(\omega)\); Seven: Search for the maximum value of \(s(\omega)\) and use CFAR detection to identify the motion information; The speed information obtains the Doppler frequency \(F\) through the sampling period \(T\), \(F = fV' / c\), then the speed \(V'=Fc / f\); The main - controlled street lamp increases the lighting brightness during the continuous lighting time, and obtains the minimum time for continuous lighting brightening according to the speed information and the lamp distance: Let the continuous lighting brightening time be \(T0\), then: \(T0\geq d / V'\), where \(d\) is the lamp distance.

2. The intelligent on-demand lighting control system based on radar sensing according to claim 1, characterized in that: The lamp distance \(d = t_dc / 2\).

3. The intelligent on-demand lighting control system based on radar sensing according to claim 2, wherein: The single - lamp controller on the main - controlled street lamp sends a lighting brightening or turning - on request to \(n\) consecutive controlled street lamps located in front of the driving direction of the motion information, specifically including: Obtain the identifiers corresponding to each of the consecutive n controlled streetlights in front of the moving main control streetlight; Form a request data packet by combining the identifier corresponding to each controlled streetlight with the identifier of the main control streetlight and the continuous lighting brightening time; Send the request data packet to the single-lamp controller of the controlled streetlight; where n > 3.

4. An intelligent on-demand lighting control system based on radar sensing according to claim 3, characterized in that: The single-lamp controller on the main control streetlight controls the controlled streetlights behind the moving information to brighten. If the number of controlled streetlights is m, then the continuous lighting brightening time T satisfies T = m * T0, m ≥ 1.

5. An intelligent on-demand lighting control system based on radar sensing according to claim 1 or 4, characterized in that: The streetlight is powered by a digital power supply UART. After receiving the motion information, the single-lamp controller controls the digital power supply UART to supply power to achieve streetlight lighting brightness adjustment and on / off control.

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