Driver assistance systems

Abstract

A person riding in a moving vehicle can obtain distance information without reading a display on the ground, and without having a device installed in the vehicle measure the distance to a fixed point. [Solution] The acquisition unit 211 acquires distance information from the distance measuring device 1. The modulation unit 212 identifies the section to which the location of the vehicle T belongs from the distance information and instructs the illumination device 3 to emit light modulated with a flashing pattern indicating that section. The illumination device 3 emits light according to the instruction. The video camera 4 supplies video data of the light to the terminal device 5. The demodulation unit 511 demodulates the pattern shown by the change in light intensity over time and generates a pulse waveform signal. The calculation unit 512 calculates the flashing period and duty cycle from the pulse waveform signal. The instruction unit 513 identifies the section name associated with the flashing period and duty cycle and outputs it to the driver from the output unit 55.

Description

Technical Field

[0001] The present invention relates to a driving support system that supports vehicle driving in accordance with the distance from a fixed point.

Background Art

[0002] Conventionally, a system for measuring the position of a vehicle using a visible light communication system is known (see, for example, Patent Document 1). The system described in Patent Document 1 realizes low-cost and high-accuracy position measurement by receiving a signal from a visible light communication beacon installed on a road lighting lamp with a monocular camera mounted on the vehicle.

[0003] There also exists a technique for accurately stopping a train at a predetermined stop position by calculating the speed and deceleration of the train with a ground control device, and instructing the driver to make a specific change in brake operation via a display device (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of Invention

Problems to be Solved by the Invention

[0005] However, in the system of Patent Document 1, since the content of the signal emitted by the visible light communication beacon is fixed, the device on the moving body side needs to hold information such as the position of the beacon before traveling. Further, in the system of Patent Document 1, the device on the moving body side cannot accurately calculate the height and position of the beacon due to image displacement, so the measurement accuracy of distance and position deteriorates.

[0006] Furthermore, the technology described in Patent Document 2 requires the train driver, who is on board a moving train, to recognize the flashing of a display device installed on the ground.

[0007] One of the objectives of the present invention is to provide a driving assistance system that allows a person riding in a moving vehicle to acquire distance information without reading a display installed on the ground, and without having a device installed in the vehicle measure the distance to a fixed point. [Means for solving the problem]

[0008] The present invention provides, in its first embodiment, a driving assistance system that measures the distance to a moving vehicle from a fixed point, irradiates the vehicle with light corresponding to a modulated pattern of information indicating the distance from the fixed point, and demodulates the received light in the vehicle to output the information.

[0009] According to the first embodiment of the driver assistance system, a person riding in a moving vehicle can acquire distance information without reading a display installed on the ground and without having a device installed in the vehicle measure the distance to a fixed point.

[0010] In the first embodiment of the driver assistance system, a configuration in which the light includes visible light, infrared light, or ultraviolet light may be adopted as a second embodiment.

[0011] According to the second embodiment of the driver assistance system, a device installed on a moving vehicle can acquire information about the distance to a fixed point by sensing visible light, infrared light, or ultraviolet light.

[0012] In the first embodiment of the driver assistance system, a third embodiment may be adopted in which the pattern is a pattern based on the difference in the flashing period and duty cycle of the light.

[0013] According to the third embodiment of the driving assistance system, a device installed on a moving vehicle can acquire information about the distance to a fixed point by identifying a pattern based on the difference in the flashing period and duty cycle of the light.

[0014] A fourth embodiment may be adopted in which, in the first embodiment of the driver assistance system, the speed of the vehicle is controlled based on the outputted information.

[0015] According to the fourth embodiment of the driver assistance system, the speed of the vehicle can be controlled based on information about the distance from the moving vehicle to a fixed point.

[0016] In the first embodiment of the driver assistance system, a fifth embodiment may be adopted in which the vehicle is stopped at a position corresponding to the fixed point based on the outputted information.

[0017] According to the fifth embodiment of the driver assistance system, the vehicle can be stopped at a position corresponding to the fixed point based on information about the distance from the moving vehicle to the fixed point.

[0018] A sixth embodiment may be adopted in which, in the first embodiment of the driver assistance system, driving instructions based on the outputted information are presented to the driver of the vehicle.

[0019] According to the sixth embodiment of the driver assistance system, driving instructions can be presented to the driver of a vehicle based on information about the distance from the moving vehicle to a fixed point. [Brief explanation of the drawing]

[0020] [Figure 1] A diagram showing the arrangement of the overall configuration of the driver assistance system 9 according to an embodiment of the present invention. [Figure 2] A block diagram showing an example of the overall configuration of this driver assistance system 9. [Figure 3] A diagram showing an example of the configuration of the information processing device 2. [Figure 4]Figure showing an example of the configuration of the distance range DB 221. [Figure 5] Figure showing an example of patterns. [Figure 6] Figure showing an example of the configuration of the terminal device 5. [Figure 7] Figure showing an example of the configuration of the control information DB 521. [Figure 8] Figure showing an example of the functional configuration of the driving support system 9. [Figure 9] Flowchart showing an example of the operation flow of the information processing device 2. [Figure 10] Flowchart showing an example of the operation flow of the terminal device 5. [Mode for Carrying Out the Invention]

[0021] <Embodiment> <Configuration of Driving Support System> Figure 1 is a diagram illustrating the arrangement of the overall configuration of a driving support system 9 according to an embodiment of the present invention. Further, Figure 2 is a block diagram showing an example of the overall configuration of this driving support system 9. This driving support system 9 includes a distance measuring device 1, an information processing device 2, an irradiation device 3, a video camera 4, a terminal device 5, and a driving control device 6.

[0022] Among these, the distance measuring device 1 is installed at a fixed point P. The fixed point P is a predetermined position and fixed point on the ground, and is defined based on, for example, a traffic signal, a sign, a roadside structure, a utility pole, a stop point, or the like.

[0023] The information processing device 2 and the irradiation device 3 are installed in the vicinity of the fixed point P on the ground. That is, the distance measuring device 1, the information processing device 2, and the irradiation device 3 constitute an on-ground configuration. The fixed point P may have a width or size, such as a region defined from the fixed point, for example. Therefore, the information processing device 2 and the irradiation device 3 installed in the vicinity of the fixed point P may be regarded as being located at the fixed point P.

[0024] On the other hand, the video camera 4, terminal device 5, and driving control device 6 are installed in the moving vehicle T. In other words, the video camera 4, terminal device 5, and driving control device 6 are installed inside the vehicle. The vehicle T is, for example, a railway vehicle such as a train, electric train, or freight car. However, the vehicle T may also be an automobile or a bus.

[0025] The distance measuring device 1 is installed at a fixed point P and measures the distance to the vehicle T. The distance measuring device 1 measures the aforementioned distance using, for example, the so-called ToF (Time of Flight) method. That is, the distance measuring device 1 irradiates pulses of electromagnetic waves such as infrared rays from an LED (light-emitting diode) or the like towards the vehicle T, receives the reflected pulses reflected by the vehicle T, and measures the distance to the vehicle T from the time of flight. Therefore, this distance measuring device 1 is an example of a configuration in a driver assistance system that measures the distance to a moving vehicle from a fixed point.

[0026] The distance measuring device 1 is connected to the information processing device 2 in a communicative manner and transmits the measured distance information (referred to as distance information) to the information processing device 2. The distance measuring device 1 may also measure the distance to vehicle T using methods other than those described above. For example, the distance measuring device 1 may measure the distance to vehicle T by triangulation based on images obtained from stereo cameras installed at multiple locations to photograph vehicle T. Alternatively, the distance measuring device 1 may measure the distance using an ultrasonic sensor.

[0027] When the information processing device 2 acquires distance information measured by the distance measuring device 1, it modulates this information into a flashing light pattern and instructs the illumination device 3 to emit light along this pattern.

[0028] The illumination device 3 comprises a light-emitting element such as an LED (light-emitting diode), a control circuit that controls the irradiation of light by this light-emitting element, and an interface that receives control signals from the information processing device 2. The illumination device 3 irradiates light toward the vehicle T along a modulated pattern according to the instructions of the information processing device 2. Therefore, the illumination device 3 and the aforementioned information processing device 2 are examples of a configuration in a driver assistance system that irradiates light toward a vehicle from a fixed point, according to a modulated pattern that indicates the distance from the fixed point to the moving vehicle.

[0029] The light emitted by this example illumination device 3 is visible light that can be captured by the video camera 4, but it does not have to be visible light as long as the light receiving device installed in the vehicle T can receive it. The illumination device 3 may emit, for example, infrared or ultraviolet light. In other words, this illumination device 3 may emit light that includes visible light, infrared light, or ultraviolet light.

[0030] The video camera 4 includes, for example, an optical system such as a lens, and an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor, and generates video data by capturing the target at predetermined intervals. This video camera 4 is installed at the front of the vehicle T, facing the illumination device 3 near the fixed point P. The video camera 4 also captures the light emitted from the illumination device 3 at, for example, a frame rate of 60fps. The video camera 4 supplies the captured video data to the terminal device 5.

[0031] The terminal device 5 extracts the light emitted by the illumination device 3 from the video data supplied by the video camera 4, demodulates its pattern, and obtains distance information (distance information) from the fixed point P to the vehicle T. The terminal device 5 outputs the acquired distance information to the driver. In other words, this terminal device 5 and the aforementioned video camera 4 are an example of a configuration in which the received light in a vehicle is demodulated and distance information from the fixed point P to the vehicle T is output.

[0032] Furthermore, the terminal device 5 transmits control information corresponding to the distance information to the driving control device 6. This control information indicates the content of the driving control to be instructed to the vehicle T.

[0033] The driving control device 6 acquires the distance information described above from the terminal device 5. Based on this distance information, the driving control device 6 controls the operation of the vehicle by exchanging information with the traction device T1, braking device T2, and speedometer T3 installed in the vehicle T. The traction device T1 is a device that transmits power from the main motor or internal combustion engine to the wheels to accelerate the vehicle. The braking device T2 is a device that decelerates and stops the vehicle T using braking mechanisms such as drum brakes or disc brakes installed on the wheels. The speedometer T3 is an instrument that has a tachogenerator (rotation meter generator) that generates a DC voltage proportional to the rotational speed of the wheels or axles, and measures the speed of the vehicle based on this.

[0034] Furthermore, the driver assistance system 9 according to the embodiment of the present invention may be used as an automatic train stopping system at a platform during automated railway operation, as an example of its application.

[0035] <Configuration of the information processing device> Figure 3 shows an example of the configuration of an information processing device 2. This information processing device 2 includes a processor 21, memory 22, interface 23, operation unit 24, and display unit 25. These components are connected to each other in a way that allows them to communicate with one another, for example, by a bus.

[0036] Memory 22 includes RAM (Random Access Memory), ROM (Read Only Memory), a solid-state drive, a hard disk drive, etc., and stores computer programs (hereinafter simply referred to as programs). Memory 22 also stores the distance range DB221.

[0037] The processor 21 controls each part of the information processing device 2 by reading and executing a program from the memory 22. The processor 21 is, for example, a CPU (Central Processing Unit). Alternatively, the processor 21 may be, for example, an FPGA (Field Programmable Gate Array), or may include an FPGA. Furthermore, this processor may have an ASIC (Application Specific Integrated Circuit) or other programmable logic device, and control may be performed by these.

[0038] Interface 23 is a communication circuit that connects the information processing device 2 to other devices via wired or wireless means. This interface 23 is connected to the range measuring device 1 and receives distance information from the range measuring device 1. Furthermore, this interface 23 is connected to the illumination device 3 and transmits instructions from the processor 21 to the illumination device 3.

[0039] The control unit 24 is equipped with various control elements such as control buttons, a keyboard, a touch panel, and a mouse for issuing various instructions. It receives operations and sends signals corresponding to the operations to the processor 21. These operations include, for example, pressing keys on the keyboard or making gestures on the touch panel.

[0040] The display unit 25 has a display screen such as a liquid crystal display and displays images under the control of the processor 21. A transparent touch panel of the operation unit 24 may be placed on top of the display screen.

[0041] The information processing device 2 does not necessarily have to have an operation unit 24 and a display unit 25. The information processing device 2 may be operated from an external device via an interface 23, or it may present information to an external device.

[0042] <Configuration of distance-range database> Figure 4 shows an example of the configuration of the distance range DB221. The distance range DB221 is a database that stores data in association with a range based on the distance from a fixed point P to a vehicle T (referred to as the distance range) and sections distinguished by the content of the vehicle T's driving control. The distance range DB221 shown in Figure 4 stores items such as section name, pattern, and distance range in association with each other.

[0043] In this distance range DB221, "Section Name" is an item that describes the name of the section that is distinguished by the content of the vehicle T's driving control.

[0044] The "distance range" is an item that describes the distance range to which the distance from fixed point P to vehicle T belongs. For example, the distance range may have an upper or lower limit, and the processor 21 compares the distance information obtained from the distance measuring device 1 with these upper or lower limits to determine the distance range to which the distance from fixed point P to vehicle T belongs.

[0045] The "Pattern" item describes the flashing pattern determined according to the distance range. Figure 5 shows examples of patterns. Figure 5(a) shows a pattern in which four relatively short on periods alternate with a fixed off period in between. On the other hand, Figure 5(b) shows a pattern in which relatively long on periods and relatively short on periods alternate.

[0046] These patterns each have a different flashing period (hereinafter also simply referred to as the period) and a different duty cycle. The duty cycle is the ratio of the total length of the on time (the time the light is on) to the length of the flashing period.

[0047] In other words, these patterns are examples of patterns based on differences in the flashing period and duty cycle of light. The processor 21 can cause the irradiator 3 to emit light along these patterns, thereby allowing distance information to be embedded in the light.

[0048] <Terminal device configuration> Figure 6 shows an example of the configuration of a terminal device 5. This terminal device 5 includes a processor 51, memory 52, interface 53, operation unit 54, and output unit 55. These components are connected to each other in a communicative manner, for example, by a bus.

[0049] Memory 52 contains RAM, ROM, a solid-state drive, a hard disk drive, etc., and stores programs. This memory 52 also stores control information DB 521.

[0050] The processor 51 controls each part of the terminal device 5 by reading and executing a program from the memory 52. ​​The processor 51 is, for example, a CPU. Alternatively, the processor 51 may be, for example, an FPGA, or may include an FPGA. Furthermore, this processor may have an ASIC or other programmable logic device, and control may be performed by these.

[0051] Interface 53 is a communication circuit that connects the terminal device 5 to other devices via wired or wireless means, enabling communication. This interface 53 is connected to the video camera 4 and receives video data from the video camera 4. Furthermore, this interface 53 is connected to the operation control device 6 and transmits instructions from the processor 51 to the operation control device 6.

[0052] The control unit 54 is equipped with various control elements such as control buttons, a keyboard, a touch panel, and a mouse for issuing various instructions. It receives operations and sends signals corresponding to the operations to the processor 51. These operations include, for example, pressing keys on the keyboard or making gestures on the touch panel.

[0053] The output unit 55 has a display screen such as a liquid crystal display and displays an image under the control of the processor 51. A transparent touch panel of the operation unit 54 may be placed on top of the display screen.

[0054] Furthermore, the output unit 55 has a sound-emitting device such as a speaker. The output unit 55 emits sound from this speaker in response to instructions from the processor 51. In addition to image display and sound output, the output unit 55 may also present information to the driver by, for example, outputting vibrations.

[0055] The terminal device 5 does not necessarily have to have an operation unit 54 and an output unit 55. The terminal device 5 may be operated from an external device via an interface 53, or it may present information to an external device.

[0056] <Configuration of the control information database> Figure 7 shows an example of the configuration of the control information DB521. The control information DB521 is a database that stores control information that indicates the content of the driving control instructed to the vehicle T when it is in that section, in association with each section. The control information DB521 shown in Figure 7 stores the section name, pattern, and control information items in association with each other.

[0057] In this control information DB521, the "section name" and "pattern" are items common to the distance range DB221 described above. The "control information" is an item that describes the content of the driving control instructed to vehicle T when vehicle T is located in the section distinguished by the corresponding section name. The content of the driving control includes, for example, the speed of vehicle T and the stopping position.

[0058] For example, the corresponding "control information" describes that when vehicle T is in a "powering section," it is instructed to accelerate. Furthermore, the corresponding "control information" describes that when vehicle T is in a "coasting section," it is instructed to coast, and when it is in a "braking section," it is instructed to decelerate or stop.

[0059] The processor 51 extracts the time-dependent changes in the light emitted by the illumination device 3 from the video data supplied by the video camera 4, and demodulates the flashing pattern of the light from these time-dependent changes. Then, the processor 51 calculates the flashing period and duty cycle from the obtained pattern, and identifies the corresponding control information from the control information DB 521. The processor 51 transmits instructions corresponding to the identified control information to the operation control device 6 via the interface 53.

[0060] <Functional Configuration of the Driver Assistance System> Figure 8 shows an example of the functional configuration of the driver assistance system 9. The processor 21 of the information processing device 2 that constitutes the driver assistance system 9 functions as the acquisition unit 211 and modulation unit 212 shown in Figure 8 by reading and executing a program stored in the memory 22.

[0061] Furthermore, the processor 51 of the terminal device 5 that constitutes the driver assistance system 9 functions as the demodulation unit 511, calculation unit 512, and instruction unit 513 shown in Figure 8 by reading and executing the program stored in the memory 52.

[0062] The acquisition unit 211 acquires distance information from the distance measuring device 1. The modulation unit 212 identifies the section to which the location of the vehicle T belongs from the acquired distance information based on the distance range DB221 of the memory 22, and identifies a flashing pattern that indicates that section. The modulation unit 212 then instructs the illumination device 3 to emit light modulated with the identified pattern.

[0063] The illumination device 3 illuminates the vehicle T with light that flashes in the pattern described above, according to the instructions. The video camera 4 captures the light emitted by the illumination device 3, generates video data, and supplies it to the terminal device 5.

[0064] The demodulation unit 511 extracts the time-dependent change in the intensity of the irradiated light from the video data supplied from the video camera 4, and demodulates the pattern shown by this time-dependent change to generate a pulse waveform signal.

[0065] The calculation unit 512 calculates the flashing period and duty cycle from the pulse waveform signal demodulated from the pattern of light change over time. The instruction unit 513 refers to the control information DB 521 and identifies the section name associated with the flashing period and duty cycle calculated by the calculation unit 512. The instruction unit 513 then outputs this section name to the driver in the vehicle T via the output unit 55. The driver performs driving operations to power, coast, or brake the vehicle T according to the section name.

[0066] Furthermore, the control information DB521 mentioned above may include driving instructions (also called driving commands) that should be presented to the driver when the vehicle T is in the section indicated by the section name, within the control information stored in association with the section name. In this case, the instruction unit 513 may cause the output unit 55 to present the driving commands associated with this section to the driver in the vehicle T, either in place of or in addition to the section name mentioned above. In other words, the processor 51 that functions as the instruction unit 513 and the output unit 55 that presents driving commands by outputting in response to the instructions of the processor 51 are an example of a configuration in a driver assistance system that presents driving commands based on information output by demodulating received light to the driver of a vehicle.

[0067] Furthermore, the instruction unit 513 identifies control information associated with the flashing period and duty cycle. The instruction unit 513 transmits an instruction corresponding to the identified control information to the operation control device 6.

[0068] The driving control device 6 controls the vehicle T according to the instructions. As a result, the vehicle T accelerates, coasts, or brakes depending on its distance from the fixed point P, and stops, for example, at a position at a predetermined distance from the fixed point P (a position corresponding to the fixed point P).

[0069] In other words, this driving control device 6 is an example of a configuration in a driving assistance system that controls the vehicle's speed based on information output by demodulating the received light. Furthermore, this driving control device 6 is an example of a configuration in a driving assistance system that stops the vehicle at a fixed point based on information output by demodulating the received light.

[0070] <Operation of the driver assistance system> <Operation of the Information Processing Device> Figure 9 is a flowchart showing an example of the operation flow of the information processing device 2. The processor 21 of the information processing device 2 determines whether or not the vehicle T has entered a predetermined area to be controlled (referred to as the control area) based on the signal transmitted from the distance measuring device 1 (step S101). While it is determined that the vehicle T has not entered the control area (step S101; NO), the processor 21 continues this determination process.

[0071] On the other hand, when it is determined that vehicle T has entered the control area (step S101; YES), the processor 21 acquires the distance information described above from the distance measuring device 1 (step S102). This distance information indicates the distance from the fixed point P where the distance measuring device 1 is installed to the front of vehicle T.

[0072] The processor 21 identifies the section in which the vehicle T is located based on the acquired distance information (step S103), and generates a pulse waveform signal modulated by a light flashing pattern corresponding to this section (step S104). Then, the processor 21 instructs the illumination device 3 to emit light according to this pulse waveform signal (step S105).

[0073] The processor 21 determines whether or not vehicle T has stopped based on the distance information continuously acquired from the distance measuring device 1 (step S106). If it determines that vehicle T has not stopped (step S106; NO), the processor 21 returns to step S102. On the other hand, if it determines that vehicle T has stopped (step S106; YES), the processor 21 terminates the process.

[0074] <Operation of terminal device> Figure 10 is a flowchart showing an example of the operation flow of terminal device 5. The processor 51 of terminal device 5 determines whether or not it is receiving light emitted from the illumination device 3 based on the video data acquired from the video camera 4 (step S201). While it is determined that it is not receiving light (step S201; NO), the processor 51 continues this determination process.

[0075] On the other hand, if it is determined that light has been received (step S201; YES), the processor 51 extracts the time-dependent changes in the light irradiated by the illumination device 3 from the video data, demodulates these time-dependent changes, and generates a pulse waveform signal (step S202). Then, the processor 51 calculates the blinking period and duty cycle from this generated pulse waveform signal (step S203), and identifies the section in which vehicle T is located based on the section name associated with these (step S204). Having identified the section in which vehicle T is located, the processor 51 identifies the control information associated with that section and sends driving instructions based on this control information to the driving control device 6. In addition, the output unit 55 outputs displays or sounds to assist the driver in driving.

[0076] The processor 51 continuously obtains the speed of vehicle T from the speedometer T3 (see Figure 2) and determines whether or not vehicle T has stopped based on this (step S206). If it is determined that vehicle T has not stopped (step S206; NO), the processor 51 returns to step S202. If it is determined that vehicle T has stopped (step S206; YES), the processor 51 terminates the process.

[0077] The processor 51 may also calculate the distance traveled by vehicle T based on the continuously acquired speed of vehicle T, and determine whether the identified section is correct.

[0078] As a result, the driver assistance system 9 can provide the driver of vehicle T with real-time information on the distance of vehicle T from the fixed point P and what driving operations should be performed. Therefore, the driver of the moving vehicle T does not need to read any displays installed on the ground.

[0079] Furthermore, this driver assistance system 9 does not analyze the video data captured by the video camera 4 on a pixel-by-pixel basis to measure, for example, the distance to the object being filmed. Therefore, there is no decrease in the accuracy of distance measurement due to image analysis.

[0080] The configurations, shapes, sizes, and arrangements described in the above embodiments are merely schematic representations to the extent that the present invention can be understood and implemented. Therefore, the present invention is not limited to the described embodiments and can be modified in various forms as long as it does not deviate from the scope of the technical idea set forth in the claims.

[0081] <Variation> The above describes the embodiment, but the contents of this embodiment can be modified as follows. Furthermore, the following modifications may be combined.

[0082] <1> In the embodiment described above, there were three different sections of control information, but the number of sections is not limited to this and may be two or four or more. Furthermore, the information processing device 2 may directly encode and modulate the measured distance information to the vehicle T and issue an irradiation instruction to the irradiation device 3 along the modulated pattern. In this case, the terminal device 5 can directly obtain the encoded distance information from the flashing light pattern extracted from the video data. The terminal device 5 may calculate the speed at which the vehicle T should move from this distance information according to a predetermined mathematical formula.

[0083] <2> In the embodiments described above, the modulated and demodulated irradiation pattern was a pattern based on the difference in the flashing period and duty cycle of the light. However, the driver assistance system 9 may use a pattern modulated and demodulated by other methods. In other words, the driver assistance system 9 may modulate distance information by amplitude and intensity modulation of light, time-domain modulation (pulse width modulation, pulse position modulation, pulse interval modulation), etc., and cause the irradiation device 3 to irradiate with light based on the modulated pattern.

[0084] <3> Furthermore, if the video data captured by the video camera 4 can be recognized by distinguishing colors on the terminal device 5, distance information may be encoded using the wavelengths of light that represent these colors. In other words, the driver assistance system 9 may modulate the distance information using wavelength division multiplexing.

[0085] <4> Furthermore, if the video data captured by the video camera 4 can be recognized by distinguishing the polarization in the terminal device 5, distance information may be encoded using these polarizations. In other words, the driver assistance system 9 may modulate distance information using polarization code / time modulation.

[0086] <5> In the embodiment described above, the flashing pattern of the light emitted by the illumination device 3 was associated with one of three sections, but this pattern may include identification information of the ground-based distance measuring device 1, information processing device 2, or illumination device 3. In other words, the information processing device 2 may encode this identification information and include it in the pattern described above.

[0087] In this case, terminal device 5 may distinguish the devices indicated by the identification information obtained by demodulating the flashing patterns. For example, if terminal device 5 obtains multiple pieces of identification information, it may select one of them. The results of a comparison of the corresponding light intensity may be used to select the identification information.

[0088] <6> Furthermore, the information processing device 2 may acquire environmental information around the fixed point P, encode this environmental information, and include it in the pattern described above. For example, the information processing device 2 may acquire weather information around the fixed point P from a server device that stores weather forecast information and include it in the pattern described above. In addition, the information processing device 2 may acquire environmental information such as rainfall, wind speed, sunshine, temperature, and humidity from various sensors installed near the fixed point P.

[0089] <7> In the embodiment described above, the driver assistance system 9 included the information processing device 2 as a separate component from the distance measuring device 1 and the illumination device 3. However, the information processing device 2 may be integrated into either the distance measuring device 1 or the illumination device 3. In this case, the functions of the information processing device 2 can be realized using a control circuit / processor that controls either the distance measuring device 1 or the illumination device 3, and the memory contained therein.

[0090] <8> Furthermore, although the driver assistance system 9 included the terminal device 5 as a separate component from the driver control device 6, the terminal device 5 may also be integrated into the driver control device 6. [Explanation of Symbols]

[0091] 1... Distance measuring device, 2... Information processing device, 21... Processor, 211... Acquisition unit, 212... Modulation unit, 22... Memory, 221... Distance range DB, 23... Interface, 24... Operation unit, 25... Display unit, 3... Illumination device, 4... Video camera, 5... Terminal device, 51... Processor, 511... Demodulation unit, 512... Calculation unit, 513... Instruction unit, 52... Memory, 521... Control information DB, 53... Interface, 54... Operation unit, 55... Output unit, 6... Driving control device, 9... Driving support system.

Claims

1. The distance to the moving vehicle is measured from a fixed point. Light corresponding to a pattern modulated with the distance information is shone from the fixed point toward the vehicle, In the aforementioned vehicle, the received light is demodulated and the information is output. Driver assistance system.

2. The aforementioned light includes visible light, infrared light, or ultraviolet light. The driver assistance system according to claim 1.

3. The aforementioned pattern is a pattern based on the difference in the flashing period and duty cycle of the light. The driver assistance system according to claim 1.

4. Based on the outputted information, the vehicle's speed is controlled. The driver assistance system according to claim 1.

5. Based on the outputted information, the vehicle is stopped at a position corresponding to the fixed point. The driver assistance system according to claim 1.

6. The driver of the vehicle is presented with driving instructions based on the outputted information. The driver assistance system according to claim 1.

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