System and program

Abstract

To provide a technology capable of acquiring information related to a change of a traveling direction of a vehicle even when it is not possible to acquire a handle steering angle from a steering angle sensor without requiring labor or costs for installing sensors in a plurality of different wheels, and for wire-connecting those sensors, respectively.SOLUTION: A radar detector includes a control part 18 for acquiring information related to rotation of wheels installed in a vehicle from a network for performing control about the vehicle, and for acquiring information related to a change of a traveling direction of the vehicle on the basis of a relation between the acquired information related to the rotation of at least two different wheels.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a system and program for determining information regarding, for example, a change in the direction of travel of a vehicle. [Background technology]

[0002] In-vehicle electronic devices such as navigation devices and radar detectors determine the vehicle's position based on signals obtained by GPS receivers receiving radio waves from GPS satellites. However, it is often difficult to receive GPS radio waves when the vehicle is in a tunnel, underground, in a crowded area with buildings, under an elevated road, etc.

[0003] For this reason, when in-vehicle electronic devices cannot receive GPS signals, they calculate the vehicle's direction of travel, inclination, distance traveled, etc. based on signals from the vehicle's gyro sensor, acceleration sensor, speed sensor, etc., and correct the vehicle's position.

[0004] However, it is more accurate to determine the vehicle's traveling direction from a signal from a steering angle sensor that detects the steering angle of the steering wheel. Therefore, as disclosed in Patent Document 1, if a vehicle is equipped with a steering angle sensor, changes in the vehicle's traveling direction can be accurately detected by acquiring a signal from the steering angle sensor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-35566 Summary of the Invention [Problem to be solved by the invention]

[0006] However, not all vehicles are equipped with steering angle sensors, and many vehicles do not have steering angle sensors. Even in vehicles that are equipped with steering angle sensors, there are cases where the signal of the steering wheel angle from the steering angle sensor cannot be obtained from the network that controls the vehicle. Furthermore, the data format of the steering wheel angle is not made public, and it may be difficult to obtain the steering wheel angle.

[0007] Patent Document 1 also describes that the traveling direction of a vehicle can be detected by detecting the difference between the inner and outer wheels of the wheels without using such a steering angle sensor. Furthermore, the same document describes that the amount of displacement of the heading can be calculated by detecting the turning of the vehicle from the output pulse difference (difference in the travel distance) of left and right vehicle speed sensors.

[0008] However, to achieve this configuration, it is necessary to install new vehicle speed sensors for each of the different wheels and connect each of these vehicle speed sensors to the system via wires, which requires time and cost for installation.

[0009] In addition, conventional vehicle speed sensors can only output signals of about 2 to 8 pulses per rotation, so high resolution cannot be achieved. For this reason, even if a vehicle speed sensor is used, the accuracy is only enough to detect whether the vehicle is turning right or left, and it does not achieve the same level of accuracy as a steering angle sensor.

[0010] Therefore, for example, it cannot detect a change in direction at a branch where the angle is not large.Also, for example, when exiting a highway, it cannot detect a state where the vehicle is exiting at an angle to the main road.Furthermore, it cannot detect a change in direction when changing lanes or when changing direction within the same lane.

[0011] The present invention has been proposed to solve the above problems, and aims to provide a system etc. that can obtain information regarding changes in the vehicle's direction of travel, even when it is not possible to obtain steering wheel angle from a steering angle sensor, without the effort and cost of installing sensors on multiple different wheels and connecting them by wires. [Means for solving the problem]

[0012] In order to achieve the above object, the system of the present invention comprises: (1) The present invention is characterized in that information regarding the rotation of the wheels of a vehicle is obtained from a network that controls the vehicle, and information regarding a change in the vehicle's direction of travel is obtained based on the relationship between the obtained information regarding the rotation of at least two different wheels.

[0013] In this way, information regarding changes in the direction of travel can be obtained simply by connecting to a network that controls the vehicle. Therefore, for example, it is not necessary to install sensors on multiple different wheels and connect these sensors with wires. This is particularly effective in cases where the steering angle, etc. cannot be obtained from the network that controls the vehicle, or where the data format, etc. is not publicly available and it is difficult to obtain the information.

[0014] Also, for example, in a configuration in which information on a change in the vehicle's traveling direction is obtained by GPS, information on a change in the vehicle's traveling direction cannot be obtained in a place where the GPS radio waves are blocked and positioning is not possible, but information on a change in the vehicle's traveling direction can be obtained by obtaining information on the rotation of at least two different wheels. For example, a configuration may be provided in which the mileage obtained by GPS is corrected based on information on the change in the vehicle's traveling direction. Furthermore, in the case of a vehicle without a steering angle sensor, even if the steering angle sensor has a limited use, or even if the steering angle sensor is broken, information on a change in the vehicle's traveling direction can be obtained by obtaining signals related to the rotation of at least two different wheels.

[0015] The information on the rotation of the wheels may be, for example, the amount of rotation of the wheels per unit time, such as the number of rotations of the wheels per unit time or the rotation angle of the wheels per unit time. In addition, the information on the rotation of the wheels may be configured to read information sent to the network at a predetermined time interval in order to control the vehicle. Furthermore, the information on the rotation of the wheels may be, for example, information from a sensor installed on each wheel of an existing vehicle and outputting information according to the rotation of the wheels. In this way, for example, a user can easily connect the sensor to the network and use it later.

[0016] The network for controlling the vehicle may be, for example, a network outside the vehicle, but is preferably a network provided in the vehicle. In particular, it is preferably a network through which data used for controlling the vehicle itself flows. In particular, it is preferably a network to which multiple computers for controlling the vehicle are connected, such as a CAN. The resolution of information on the rotation of the wheels in the network through which data used for controlling the vehicle itself flows is 10 to 100 times higher than the vehicle speed (1 km / h step), so that the quantum error is small, and even when driving at a low speed, the error of information on the change in the traveling direction of the vehicle obtained from the information on the rotation of the wheels is also extremely small. For this reason, it is possible to obtain information on the change in the traveling direction with a level of accuracy comparable to that of a steering angle sensor, for example.

[0017] In addition, for example, it is possible to calculate vehicle speed and distance traveled from information regarding wheel rotation in a network through which data used to control the vehicle itself flows, together with information regarding changes in the vehicle's direction of travel, and to calculate a gear ratio from separately obtained engine speed and vehicle speed, and it is also possible to reduce errors in vehicle speed, distance traveled, gear ratio, etc.

[0018] Also, for example, the network provided in the vehicle may be wired or wireless. In particular, for example, in the case of a wired network, information regarding a change in the vehicle's traveling direction can be obtained by simply connecting a wire to one point of a signal line (for example, a group of signal lines) of the network. In particular, it is preferable to configure the network signal line to be connected to a detachable connector. For example, it is preferable to configure the network to have a plug that is connected to a connector having a network signal line, such as a fault diagnosis connector provided in the vehicle.

[0019] The two different wheels may be, for example, in the case of a four-wheeled vehicle, the left and right front wheels, the left and right rear wheels, the left front wheel and the left rear wheel, the right front wheel and the right rear wheel, the left front wheel and the right rear wheel, or the right front wheel and the left rear wheel.

[0020] "At least two" may mean two or more. For example, information corresponding to only two wheels may be used. In this way, for example, the amount of information to be processed is reduced, and processing can be simplified and accelerated. In addition, for example, of the information corresponding to the two wheels and the information corresponding to the other two wheels, whichever shows a normal value may be used, or an average of both pieces of information may be used. In this way, for example, highly accurate detection is possible.

[0021] The information on the rotation of the wheels of the vehicle may be obtained from the network that controls the vehicle at predetermined time intervals. The predetermined time may be, for example, the time required to obtain information on the change in the traveling direction of the vehicle. For example, the information may be instantaneous values ​​of information on the rotation of at least two wheels at approximately the same time.

[0022] The information on the change in the traveling direction of the vehicle may be, for example, information indicating the degree of difference between the information on the rotation of at least two wheels, for example, information based on the difference in values ​​indicated by the information on the rotation of the two wheels, or information based on the ratio of values ​​indicated by the information on the rotation of the two wheels.

[0023] The change in the traveling direction may be, for example, a right or left turn at a branching point. In this way, for example, the number of directions to be determined is reduced, and processing can be simplified and accelerated. The change in the traveling direction may be, for example, a change in the traveling angle or a change in the steering wheel angle. In this way, for example, more detailed driving conditions can be determined. For example, a change in the traveling direction in the same lane and a change in the traveling direction when changing lanes can be detected. Furthermore, even if GPS positioning is not possible, a change in the traveling direction at a curve in a road at an intersection, underground, in a tunnel, etc. can be detected.

[0024] (2) It is preferable that information regarding the steering wheel angle is acquired from a network that controls the vehicle, and an abnormal condition of the vehicle is detected based on the relationship between the acquired information regarding the steering wheel angle and information regarding the steering wheel angle calculated based on the relationship between information regarding the rotation of the at least two different wheels.

[0025] Although the information on the steering wheel angle acquired from the network accurately indicates the steering wheel angle, the information on the steering wheel angle acquired based on the relationship of the information on the rotation of at least two different wheels differs from the actual steering wheel angle depending on the state of the vehicle. For this reason, for example, an abnormal state of the vehicle can be detected based on the relationship in which the two pieces of information are significantly different. For example, the following method may be used to acquire the steering wheel angle based on the relationship of the information on the rotation of the wheels. First, a log is created in which the steering wheel angle at approximately the same time and the information on the rotation of at least two different wheels are acquired at a time interval required to generate information on the change in the traveling direction of the vehicle according to the application, and a function is obtained between the relationship of the information on the rotation of at least two different wheels of the vehicle in the log and the steering wheel angle at the same time. In this system, the function is used to acquire the steering wheel angle based on the relationship of the information on the rotation of the wheels. For example, the difference or ratio of the instantaneous values ​​of the rotation speeds of two different wheels at the same time is associated with the steering wheel angle at that time and stored as a log, and the correlation between this difference or ratio and the steering angle is stored as a function. The function may be incorporated into the program as a mathematical formula, or, for example, a table for determining the mapping may be created and stored, and the program may be configured to perform calculations using this table.

[0026] For example, the data format of the information on wheel rotation and steering angle flowing through the network may differ for each vehicle model. For example, the correspondence between the information on wheel rotation and the steering angle may be obtained in advance for each vehicle model, a function may be calculated, and the function may be stored in the system as a program or data, and the system may be provided with a function for automatically detecting and setting the vehicle model or for manually setting the vehicle model, and the correspondence for the set vehicle model may be calculated. For example, an abnormal state of the vehicle, such as a flat tire or a slip, may be detected based on the relationship between the calculated steering angle and the steering angle obtained from the network.

[0027] The abnormal state of the vehicle may be, for example, a state in which the rotation speed of a specific tire is significantly different from that of the other tires, or a flat tire, an abnormality in air pressure, or a slippage of a specific tire on a snowy, icy, or muddy road.

[0028] (3) It is preferable that the information flowing through the network be read without interrogating devices connected to the network provided in the vehicle as the network for controlling the vehicle.

[0029] In this way, since information is read from the network without collecting information by querying the devices connected to the network, stress on the devices connected to the network can be avoided. In particular, stress can be avoided for the computer that outputs information about the rotation of the wheels to the network, since it does not need to respond to queries. Moreover, since there is no increase in network traffic, stress on the overall control of the vehicle can also be avoided.

[0030] (4) It is preferable to control the display of information regarding the steering angle obtained from a network that controls the vehicle and information regarding the steering angle calculated based on the relationship between information regarding the rotation of the at least two different wheels on a display screen.

[0031] In this way, the vehicle occupants including the driver who has viewed the display screen or a person outside the vehicle can compare the information on the steering wheel angle obtained from the network that controls the vehicle with the information on the steering wheel angle calculated based on the relationship between the information on the rotations of the at least two different wheels. The vehicle occupants or the person outside the vehicle who have compared the two pieces of information on the steering wheel angle in this way can determine an abnormal state of the vehicle, for example, from the degree of difference between the two pieces of information.

[0032] The display mode may be, for example, a mode that allows identification of the difference between the information on the steering angle acquired from a network that controls the vehicle and the information on the steering angle obtained based on the relationship between the information on the rotations of at least two different wheels. For example, the presence of a difference between the two pieces of information may be displayed, the magnitude of the difference may be displayed, or the type of abnormality estimated from the difference may be displayed. In this way, an abnormal state of the vehicle can be easily determined.

[0033] The display screen may be, for example, one that can display information that can be visually recognized. For example, the display screen may be one that is installed inside the vehicle. In this way, for example, a vehicle occupant who looks at the display screen can compare the two pieces of information. Also, for example, the display screen may be one that is installed outside the vehicle. In this way, for example, a person outside the vehicle can compare the two pieces of information.

[0034] (5) It is preferable that an abnormal condition of the vehicle is detected based on the relationship between information regarding the steering angle obtained from a network that controls the vehicle and information regarding the steering angle obtained based on the relationship between information regarding the rotation of the at least two different wheels, and that control is performed to display the abnormal condition on a display screen.

[0035] In this way, the abnormal condition of the vehicle is displayed on the display screen, so that the vehicle occupants, including the driver, or persons outside the vehicle can easily recognize the abnormal condition of the vehicle without having to go through the trouble of determining the abnormal condition themselves. The indication of an abnormal state may be, for example, a flat tire, abnormal air pressure, slippage of a particular tire, etc., and may be made recognizable by characters, figures, colors, or changes therein.

[0036] (6) It is preferable that information regarding a change in the traveling direction of the vehicle is displayed on a display screen.

[0037] In this way, the vehicle occupants including the driver or people outside the vehicle who are viewing the display screen can recognize the change in the vehicle's traveling direction. From this change in the vehicle's traveling direction, the vehicle occupants including the driver or people outside the vehicle can determine the driving state of the vehicle, which can be useful for safe driving and eco-driving.

[0038] The display screen may be, for example, a display screen installed inside the vehicle. In this way, for example, a passenger in the vehicle can recognize the change in the traveling direction of the vehicle. Also, for example, the display screen may be installed outside the vehicle. In this way, for example, a person outside the vehicle can recognize the change in the traveling direction of the vehicle. For example, a taxi company or a transportation company may check the past or present changes in the traveling direction of the driver's vehicle using a display screen installed in the company, determine what the driving condition is, and use it as an index to encourage the driver to drive safely or eco-drive. Also, for example, a driver may check the past changes in the traveling direction of his / her own vehicle using a display screen at home, determine what the driving condition was, and use it as an index to aim for his / her own safe driving or eco-driving.

[0039] The display of information on the change in the vehicle's traveling direction may be, for example, a display in a manner that allows the driving state of the vehicle to be determined from the presence or absence of a change in the traveling direction. For example, the display may be a manner that allows the instantaneous change in the traveling direction of the vehicle to be visually grasped. Furthermore, the display may be a manner that allows the changes in the traveling direction of the vehicle over a predetermined period to be visually grasped all at once. The predetermined period may be, for example, a period that allows the determination that lane changes are being made repeatedly in a short period of time, that the traveling direction changes frequently occur within the same lane, etc. The driving state of the vehicle determined by the vehicle occupant or a person outside the vehicle may be, for example, a driving state that is compatible with or contrary to safe driving or eco-driving. In this way, for example, it can be linked to the realization of safe driving or eco-driving by the driver of the vehicle. For example, the repeated lane changes in a short period of time may be determined by the vehicle occupant or a person outside the vehicle as a driving state of frequent overtaking. For example, the frequent changes in the traveling direction within the same lane may be determined by the vehicle occupant or a person outside the vehicle as a driving state of drunk driving or drowsy driving. As a display that can determine the driving condition, it is preferable to display, for example, a graph showing the change in the direction of travel or the steering angle over a specified period of time, or numbers showing the frequency of change in the direction of travel or the steering angle over a specified period of time.

[0040] (7) It is preferable that the driving state of the vehicle is determined based on information regarding a change in the traveling direction of the vehicle, and that control is performed to display the driving state on a display screen.

[0041] In this way, the driving status of the vehicle is displayed on the display screen, so that passengers in the vehicle, including the driver, or persons outside the vehicle who view the display screen can easily recognize the driving status of the vehicle without the hassle of determining the driving status themselves.

[0042] The driving state may be indicated, for example, by a display indicating danger, safety, drowsiness, drinking, etc., using characters, figures, colors, or changes therein.

[0043] (8) It is preferable to obtain information related to the driving operation of the vehicle, and to perform control so that the obtained information related to the driving operation of the vehicle is displayed on a display screen together with changes in the traveling direction of the vehicle.

[0044] In this way, information regarding the vehicle's driving operation is displayed along with information regarding changes in the vehicle's direction of travel, so that vehicle occupants, including the driver, or persons outside the vehicle who view the display screen can determine the vehicle's driving condition in more detail based on the relationship between changes in the vehicle's direction of travel and information regarding the driving operation.

[0045] The information on the driving operation of the vehicle may be, for example, information indicating the operation of a member or mechanism that the driver needs to operate while driving and the timing of the operation. For example, the information on the driving operation of the vehicle may be information such as when the turn signal was turned on, when and how many times the brake was pressed, and when and how many times the accelerator was pressed.

[0046] For example, if the driver does not turn on the turn signal before turning right or left, it may be determined that the driver is in a dangerous driving state. For example, if the driver does not step on the brake before turning right or left, or if the driver steps on the accelerator, it may be determined that the driver is in a dangerous driving state.

[0047] (9) It is preferable to obtain information regarding the driving operation of the vehicle, and based on the obtained information regarding the driving operation of the vehicle and changes in the direction of travel of the vehicle, determine the driving state of the vehicle and perform control to display the driving state on a display screen.

[0048] In this way, the display screen shows not only changes in the vehicle's direction of travel but also the driving state determined by taking into account information about the vehicle's driving operation, so that vehicle occupants, including the driver, or people outside the vehicle who view the display screen can easily obtain detailed driving conditions without the hassle of determining the driving state themselves.

[0049] (10) It is preferable that a control is performed to output a sound in response to the abnormal state.

[0050] In this way, by outputting a sound, it is possible to reliably notify the vehicle occupants or people outside the vehicle who are not looking at the display screen of an abnormal condition of the vehicle. For example, a flat tire, an abnormality in air pressure, slippage of a specific tire, etc. can be made known to the vehicle occupants or people outside the vehicle.

[0051] (11) It is preferable that sound output be controlled in accordance with the operating state.

[0052] In this way, by outputting a sound, it is possible to reliably inform the vehicle occupants or people outside the vehicle who are not looking at the display screen of the driving state of the vehicle. For example, it is possible to warn the vehicle occupants or people outside the vehicle of the dangers of drowsy driving or drunk driving.

[0053] (12) It is preferable that a value indicating the relationship between information regarding the rotation of the at least two different wheels at the same time is defined as a single value, and information regarding a change in the vehicle's traveling direction is obtained by using an average value of a predetermined number of consecutive values.

[0054] In this way, even if one of the multiple measurements shows a value that is significantly different from the others, the value is not used as is, but the average value of the multiple measurements is used, so that the value is smoothed to a value that is closer to the steering angle, and direction detection with high accuracy can be achieved, closer to that of the steering angle sensor.

[0055] The average value of multiple consecutive values ​​may be calculated by, for example, using the average value of multiple values, excluding the oldest value, and then calculating the average value including the next value.

[0056] (13) The information regarding the rotation of the wheels of the vehicle may be information based on a signal from a sensor used in an ABS to detect the rotation state of the wheels.

[0057] In this way, the signal from the sensor used in the ABS (anti-lock braking system) is used, which saves the effort and cost of adding a special sensor.In addition, the information based on the signal from the sensor used in the ABS has a higher resolution than the vehicle speed sensor of the transmission, so the direction can be detected accurately.

[0058] (14) It is preferable that the direction of travel of the vehicle is not detected when the ABS function is activated.

[0059] When the ABS is activated, it is not possible to accurately detect the direction of travel using signals from the sensors. Therefore, by not detecting the direction, erroneous judgments and incorrect operation due to erroneous detection can be prevented.

[0060] (15) The system functions of (1) to (14) can be configured as a program for realizing the functions on a computer. Effect of the Invention

[0061] According to the present invention, it is possible to obtain information regarding changes in the vehicle's direction of travel without the effort and cost of installing sensors on multiple different wheels and connecting them with wires, even when it is not possible to obtain steering wheel angle from a steering angle sensor. [Brief description of the drawings]

[0062] [Figure 1] 1 is a diagram showing the configuration of a radar detector according to a preferred embodiment of the present invention; [Diagram 2] FIG. 1 is a block diagram of a radar detector. [Diagram 3] FIG. 11 is an explanatory diagram showing an example of a standby screen. [Figure 4] FIG. 13 is an explanatory diagram showing an example of a warning screen. [Diagram 5] FIG. 2 is an explanatory diagram showing an example of a route actually traveled by a vehicle. [Figure 6] 6 is an explanatory diagram showing the steering wheel angle and the wheel difference ratio when traveling along the route in FIG. 5. [Figure 7] 6 is an explanatory diagram showing the steering wheel angle and the averaged wheel difference ratio when traveling along the route in FIG. 5. [Figure 8] FIG. 4A is an explanatory diagram showing the vehicle speed when the vehicle is traveling clockwise, and FIG. 4B is an explanatory diagram showing the rotational speed of each wheel. [Figure 9] FIG. 1A is an explanatory diagram showing the vehicle speed when braking is applied while the vehicle is traveling straight on a snowy road, and FIG. [Figure 10] FIG. 1A is an explanatory diagram showing the engine speed when the accelerator is depressed while the vehicle is traveling straight on a snowy road; FIG. 1B is an explanatory diagram showing the vehicle speed; and FIG. 1C is an explanatory diagram showing the rotational speed of each wheel. [Figure 11] FIG. 4B is an explanatory diagram showing the vehicle speed when the accelerator is depressed while the vehicle is traveling straight on a snowy road, and FIG. 4C is an explanatory diagram showing the rotational speed of each wheel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0063] [1. Configuration of electronic devices] Figures 1 and 2 show a radar detector 1 which is a suitable embodiment of an electronic device constituting the system of the present invention. Figure 1(a) is a perspective view of the front side (the side facing the rear of the vehicle (the driver's side)) of the radar detector 1, and Figure 1(b) is a perspective view of the rear side. Figure 2 is a block diagram of the radar detector 1.

[0064] The radar detector 1 comprises a thin rectangular case body 2, and is attached and fixed to the dashboard of a vehicle or the like using a bracket 3 attached to the lower rear side of the case body 2.

[0065] A display 5 is provided on the front surface of the case body 2 (the surface facing the rear of the vehicle (the driver's side)). The display 5 is configured as a 3.2-inch color TFT LCD display. A touch panel 6 is provided on this display 5 for detecting which part of the display 5 has been touched. In addition, a volume adjustment button 7 is provided on the right side of the front surface of the case body 2, and various operation buttons 8 are provided on the left side.

[0066] The right side of the case body 2 is provided with a card insertion slot 9 for inserting a memory card 11 as a removable recording medium, and a memory card reader 10 is built into the card insertion slot 9 inside the case body 2. By inserting the memory card 11 into the card insertion slot 9, the memory card 11 is attached to the memory card reader 10. The memory card reader 10 takes in the data stored in the attached memory card 11. More specifically, the data stored in the memory card 11 includes update information such as information on a new alarm target (location information such as longitude and latitude, type information, etc.), and the update information is stored (downloaded) in a database 19 built into the device under the control of the control unit 18, thereby updating the data.

[0067] The database 19 can be realized by a non-volatile memory (such as an EEPROM) inside the microcomputer of the control unit 18 or externally attached to the microcomputer. Note that map data and information on certain alarm targets are registered in the database 19 at the time of shipment, and data on alarm targets added thereafter is updated as described above.

[0068] A GPS receiver 13 is placed inside the upper center of the back side of the case body 2, and a microwave receiver 14 and a radio receiver 15 are placed next to it. The GPS receiver 13 receives GPS signals from GPS satellites and outputs current position (longitude and latitude) information. The microwave receiver 14 receives microwaves of a predetermined frequency emitted from the speed measurement device. The radio receiver 15 receives incoming radio waves of a predetermined frequency. A speaker 16 is also built into the bottom inside the case body 2. The speaker port is provided on the bottom surface of the case body 2.

[0069] A DC jack 12 is disposed on the lower side of the side surface of the case body 2. This DC jack 12 is for connecting a cigarette plug cord (not shown) and is connected to a cigarette lighter socket of a vehicle via the cigarette plug cord so as to receive power supply.

[0070] In addition to the above-mentioned display 5, a lamp 31, a remote control receiver 32, and an infrared communication device 34 are arranged on the front of the case body 2 (omitted from FIG. 1). The lamp 31 warns by shining in various colors according to the type and urgency of the alarm. The remote control receiver 32 communicates data with a remote control (portable device: child device) 33 via infrared rays, and performs various settings for this device. The infrared communication device 34 transmits and receives data to and from a communication device with a built-in infrared communication device, such as a mobile phone 35.

[0071] The case body 2 is provided with a geomagnetic sensor 36 and an acceleration sensor 37. The geomagnetic sensor 36 is a sensor that detects geomagnetism to determine which direction north is relative to the direction of travel. The acceleration sensor 37 is a sensor that detects the acceleration of the vehicle in the forward / backward, left / right, and up / down directions.

[0072] The radar detector 1 of this embodiment also includes a connection cable 22 that connects to an OBD-II (II is the Roman numeral "2", and hereinafter "OBD-II" will be abbreviated as "OBD2") connector installed in the vehicle. A plug 23 that can be detachably attached to the OBD2 connector of the vehicle is attached to the end of this connection cable 22. The OBD2 connector is also called a fault diagnosis connector, and is connected to the vehicle's ECU to output various vehicle information.

[0073] A connector terminal 25 is provided at the other end of the connection cable 22 for connection to a socket 24 provided on the side of the case body 2 of the radar detector 1, allowing the connection cable 22 to be attached and detached to the radar detector 1. Of course, the connection cable 22 may also be connected directly to the radar detector 1.

[0074] By connecting the plug 23 attached to the connection cable 22 with the OBD2 connector on the vehicle body side, the control unit 18 is connected to an in-vehicle network that controls the vehicle, and acquires various vehicle information every 0.5 seconds. Examples of this vehicle information include vehicle speed, engine speed, engine load factor, throttle degree, ignition timing, remaining fuel ratio, intake manifold pressure, intake air flow rate (MAF), injection open time, engine coolant temperature (coolant temperature), air temperature taken into the engine (intake air temperature), outside air temperature (outside air temperature), amount of remaining fuel in the fuel tank (remaining fuel amount), fuel flow rate, instantaneous fuel consumption, accelerator opening, turn signal information (operation of left and right turn signals (ON / OFF)), brake opening, steering wheel rotation angle information, etc.

[0075] The control unit 18 is a computer equipped with a CPU, ROM, RAM, non-volatile memory, I / O, etc., and is connected to each of the above-mentioned units, executes a predetermined process based on information input from various input devices (touch panel 6, GPS receiver 13, microwave receiver 14, wireless receiver 15, etc.), and outputs a predetermined warning message using output devices (display 5, speaker 16, etc.). These basic configurations can basically be the same as those of the past. For example, for audio output, audio PCM data is stored in an EEPROM, which is a non-volatile memory, and the control unit 18 reproduces this PCM data and outputs the audio from the speaker 16.

[0076] [2. Basic functions of electronic devices] The functions of the radar detector 1 of this embodiment are stored in the EEPROM of the control unit 18 as programs executed by the computer that is the control unit 18, and are realized by the computer executing these programs. Functions realized by the computer through the programs stored in the control unit 18 include a GPS log function, a standby screen display function, a map display function, a GPS warning function, a radar wave warning function, and a wireless warning function.

[0077] The GPS log function is a function in which the control unit 18 associates the current position detected by the GPS receiver 13 every second with the detection time and speed (vehicle speed) and stores the result in a non-volatile memory as a position history. This position history is recorded in, for example, the NMEA format.

[0078] The standby screen display function is a function for displaying a predetermined standby screen on the display 5. Fig. 3(a) shows an example of the standby screen, which shows the speed, latitude, longitude, and altitude of the vehicle detected by the GPS receiver 13.

[0079] The map display function, as shown in Fig. 3(b), is a function that accesses the database 19 based on the current position detected by the GPS receiver 13, and reads and displays the map data stored therein. The map display function also has a function that searches for objects to be warned about around the current position based on the position information stored in the database 19, and if an object to be warned about is present in the vicinity, displays information indicating the object to be warned about (such as a target icon 112) superimposed on the corresponding position on the map. Specific display modes are as follows:

[0080] The control unit 18 displays the map so that the vehicle's traveling direction always faces upward in the main display area R1 that occupies almost the entire surface of the display 5. The control unit 18 displays the map so that the current vehicle position is located at the center of the lower side of the main display area R1, and displays the vehicle icon 111 at that position.

[0081] The control unit 18 displays status information in a status area R2 set above the main display area R1. The status information displayed in the status area R2 includes, from the left, a current time 121 (in the figure, "15:10"), a GPS radio wave reception level display icon 122 (in the figure, three straight lines of different lengths standing parallel to each other, indicating the maximum reception level), a no-parking area icon 123 (displayed when the vehicle is in a most important parking area or a most important parking area), a reception sensitivity mode display icon 124 indicating the reception sensitivity of the radar (in the figure, "SE" for the highest sensitivity), a vehicle speed 125 (in the figure, "30 km / h"), and a compass 126. The status area R2 is a transparent area, and is arranged using a layer above the layer of the main display area R1. This allows the map located below to be seen in the status area R2 in places where no status information is displayed.

[0082] The control unit 18 displays the current scale information (reduction scale) in a scale display area R3 set on the left side of the main display area R1. The scale is set to 0 m for the vehicle position, and displays the distance from the vehicle position to the vertical center position of the main area R1 ("500" in the figure) and the distance to the upper position ("1000" in the figure). The unit is "m". When the control unit 18 detects that the main display area R1 is touched twice consecutively, it displays a map scale change button (not shown) at a predetermined position (position along the scale display area R3) in the main display area R1, and changes the map scale in response to the touch on the map scale change button. In other words, the control unit 18 changes the scale of the map displayed in the main display area R1 to match the scale of the changed map scale, and also changes the scale information displayed in the scale display area R3.

[0083] When the control unit 18 detects a single touch on the display unit 5 while the standby screen display function is being executed as shown in Fig. 3(a), the control unit 18 displays a menu screen. When the control unit 18 detects that a screen switching button provided in the menu screen has been touched, the control unit 18 switches to the map display function as shown in Fig. 3(b). Similarly, when the control unit 18 detects a single touch on the display unit 5 while the map display function is being executed, the control unit 18 displays a menu screen. When the control unit 18 detects that a screen switching button provided in the menu screen has been touched, the control unit 18 performs processing to switch to the standby screen display function.

[0084] The control unit 18 executes processing to realize each function such as a GPS warning function, a radar wave warning function, a wireless warning function, etc., in response to an event that occurs while executing the standby screen display function and the map display function (hereinafter, these functions are collectively referred to as the standby function), and returns to processing of the original standby function when the processing of the corresponding function ends. The priority of each function is set in the order of highest priority: radar wave warning function, wireless warning function, and GPS warning function.

[0085] The GPS warning function is a process executed at a predetermined time interval (1 second interval) in response to an event from a timer in the control unit 18. This process calculates the distance between the object to be warned stored in the database 19 and the object to be warned from the latitude and longitude of the current position detected by the GPS receiver 13, and when the calculated distance reaches a predetermined approach distance, displays a GPS warning display 130 (a schematic diagram of the object to be warned, remaining distance, etc.) as a warning screen as shown in Fig. 4(a) on the display 5, and outputs an approach warning sound from the speaker 16, indicating that the object to be warned is approaching.

[0086] The targets of such warnings include locations of drowsy driving accidents, speed measuring devices (radar type, loop coil type, H system, LH system, photocell type, mobile type, etc.), speed limit change points, enforcement areas, checkpoints, parking ban monitoring areas, N system, traffic monitoring system, intersection monitoring points, signal ignoring prevention systems, police stations, accident-prone areas, areas with high incidence of vehicle thefts, sharp / continuous curves (expressways), branching / merging points (expressways), ETC lane advance guidance (expressways), service areas (expressways), parking areas (expressways), highway oases (expressways), smart interchanges (expressways), gas stations in PAs / SAs (expressways), tunnels (expressways), highway radio receiving areas (expressways), prefectural border announcements, roadside stations, view point parking, etc., and information on the types of these targets, latitude and longitude information indicating their positions, schematic diagram or photograph data to be displayed on the display 5, and audio data are associated with each other and stored in the database 19.

[0087] FIG. 4(a) shows a display example of the radar wave warning function. This radar wave warning function is a warning function that displays a GPS warning display 131 as a warning screen on the display 5 and outputs a warning sound from the speaker 16 when the microwave receiver 14 detects a signal corresponding to microwaves in a frequency band emitted by a speed measurement device (such as a mobile radar (hereinafter simply referred to as "radar")). For example, when the microwave receiver 14 detects microwaves in a frequency band of microwaves emitted by a radar, as shown in FIG. 4(b), a schematic diagram or photo of a radar stored in the database 19 is displayed as a warning screen on the display 5, and the voice data stored in the database 19 is read out and a voice saying "This is a radar. Watch your speed" is output from the speaker 16. The distance to be displayed may be, for example, a distance estimated from the electric field strength.

[0088] The radio warning function is a function that issues a warning when the radio receiver 15 receives radio waves emitted by an emergency vehicle or the like, so as not to interfere with the vehicle's travel, etc. In the radio warning function, the frequencies of police radio, car location radio, digital radio, special small radio, police station radio, police telephone, police activity radio, tow truck radio, helicopter radio, fire helicopter radio, fire radio, emergency radio, highway radio, security radio, etc. are scanned, and when a radio signal is received at the scanned frequency, a schematic diagram indicating that a radio signal corresponding to the frequency stored in the database 19 for each radio type is received is displayed on the display 5 as a warning screen, and audio data stored in the database 19 for each radio type is read out, and an alarm sound indicating the type of radio signal is output from the speaker 16. For example, when a police radio signal is received, a sound such as "This is a police radio. Watch your speed." is output.

[0089] [3. Vehicle driving state detection function] A description will now be given of a vehicle running state detection function realized by the control unit 18 in addition to the above basic functions. The vehicle running state detection function includes a function of acquiring information about the rotation of the wheels, a function of detecting a change in direction of the vehicle, a function of detecting an abnormal state of the vehicle, and the like.

[0090] [Function for obtaining information about wheel rotation] The function of obtaining information about the rotation of the wheels is a function for obtaining information about the rotation of the wheels from an in-vehicle network that controls the vehicle. The details of this function are as follows.

[0091] First, as described above, by connecting the plug 23 of the connection cable 22 connected to the radar detector 1 to the OBD2 connector on the vehicle body side, the control unit 18 is connected to an in-vehicle network that controls the vehicle.

[0092] This in-vehicle network is a CAN (Controller Area Network) that connects computers (ECUs) arranged in various parts of the vehicle for controlling the vehicle and through which data used to control the vehicle itself flows. In this way, it is only necessary to connect the control unit 18 to the CAN that controls the vehicle. There is no need to install new sensors on multiple different wheels and connect each of these sensors with wires.

[0093] The control unit 18 does not query the ECU by transmitting a remote frame or the like. The control unit 18 acquires information on the rotation of each wheel at 10 ms intervals, which is sent to the CAN and used to control the vehicle itself. This information is used by the ABS (Anti-lock Brake System) and is information on the rotation speed of each wheel output from sensors that detect the rotational status of each of the four wheels. The resolution of the information on the rotation speed of the wheels from the sensors used by the ABS is 10 to 100 times higher than the vehicle speed (1 km / h steps).

[0094] In the case of a vehicle equipped with a steering angle sensor, as described above, steering wheel rotation angle information (steering wheel steering angle) can be obtained from OBD2. However, not all vehicles are equipped with a steering angle sensor. In this embodiment, whether the vehicle is equipped with a steering angle sensor or not, it is possible to detect the direction change of the vehicle and abnormal conditions based on the information output from the sensor used in the ABS.

[0095] [Vehicle direction change detection function] The vehicle direction change detection function is a function that detects a change in the vehicle direction as information on a change in the vehicle's traveling direction based on the relationship between information on the rotation of two different wheels acquired by the above-mentioned information acquisition function by the control unit 18. Details of this function are as follows.

[0096] First, the database 19 stores information about the rotation speed of each wheel that is acquired by the control unit 18 and transmitted over the CAN every 10 ms. Then, the control unit 18 calculates a ratio between the instantaneous values ​​of the information about the rotation speed of the two wheels at the same time, and subtracts 1 from this ratio. In this embodiment, the value calculated in this way is called the wheel difference ratio.

[0097] The two wheels for which the wheel difference ratio can be calculated are as follows: Left and right front wheels Left and right rear wheels Front left and rear left wheels Right front and right rear wheels Left front wheel and right rear wheel Right front wheel and left rear wheel

[0098] (Example of wheel difference ratio measurement during actual driving) An example of determining the wheel difference ratio of the left front wheel and the right front wheel as described above while driving on an actual road will be described. The route traveled was a gourd-shaped road connected to a straight road as shown in Figure 5, and the vehicle traveled from the straight road into the gourd shape, went around in a clockwise direction, and then exited onto the straight road again.

[0099] Fig. 6 is a graph in which the vertical axis indicates the wheel difference ratio (%) obtained by the control unit 18 as described above while traveling along the route in Fig. 5, and the horizontal axis indicates time (seconds). The total measurement time on the horizontal axis of this graph is 94 seconds. The graph in Fig. 6 also indicates, on the right vertical axis, steering wheel rotation angle information (steering wheel angle) obtained by the control unit 18 from the OBD 2 simultaneously with the measurement, in degrees (°). The graph in Fig. 6 can be displayed on the display 5 during or after the measurement, based on the data obtained by the control unit 18 as described above and stored in the database 19.

[0100] The measurement results will be specifically described below with reference to Fig. 5 and Fig. 6. The curves (1) to (9) on the route in Fig. 5 correspond to (1) to (9) in Fig. 6. The arrows in Fig. 5 indicate the traveling direction of the vehicle. First, the vehicle travels straight along the straight route on the left side in Fig. 5 and enters a gourd-shaped route. At this time, the vehicle turns left at the T-junction (1). Then, the steering angle reaches about +290.0° and the wheel difference ratio reaches about +29.00.

[0101] Next, the vehicle passes through a gentle left-hand curve (2). At this time, the steering angle reaches about +20.0° and the wheel difference ratio reaches about +2.00. Then, the vehicle passes through a right-hand curve (3). At this time, the steering angle reaches about -40.0° and the wheel difference ratio reaches about -4.00.

[0102] After that, the vehicle passes through a gentle right-curving curve (4). At this time, the steering angle is about -20.0° and the wheel difference ratio is about -2.00. Then, the vehicle passes through a right-curving curve (5). At this time, the steering angle is about -30.0° and the wheel difference ratio is about -3.00.

[0103] Next, the vehicle passes through a left-hand curve at (6). At this time, the steering angle reaches about +50.0° and the wheel difference ratio reaches about +5.00. Then, the vehicle passes through a right-hand curve at (7). At this time, the steering angle reaches about -60.0° and the wheel difference ratio reaches about -6.00. After that, the route continues almost straight, so both the steering angle and the wheel difference ratio remain near 0.

[0104] Then, the vehicle passes through the right-hand curve at (8). At this time, the steering angle reaches about -40.0° and the wheel difference ratio reaches about -4.00. The vehicle then turns left at the T-junction at (9) and exits onto a straight road. At this time, the steering angle reaches about +300.0° and the wheel difference ratio reaches about +30.00.

[0105] As a result of the above, it can be seen that the wheel difference ratio is almost identical to the steering angle. The control unit 18 can detect that the steering wheel is turned to the left if the wheel difference ratio is +, and that the steering wheel is turned to the right if the wheel difference ratio is -. In other words, it can determine not only right and left turns but also the traveling direction of the vehicle with an accuracy equivalent to the steering wheel steering angle. Also, based on a threshold value set in the database 19, it can detect whether the vehicle has turned right or left at an intersection, a T-junction, an L-junction, etc. For example, it can detect that the vehicle has turned left if the wheel difference ratio is equal to or greater than a threshold value of +10.00, and that the vehicle has turned right if the wheel difference ratio is equal to or less than a threshold value of -10.00.

[0106] The control unit 18 may obtain the wheel difference ratio as follows. The instantaneous value of the information relating to the rotation speed of the left front wheel is regarded as one value, and the average value of a predetermined number of consecutive values ​​is obtained. The instantaneous value of the information relating to the rotation speed of the right front wheel at the same time is regarded as one value, and the average value of a predetermined number of consecutive values ​​is obtained. The ratio between the average value of the left front wheel and the average value of the right front wheel obtained in this way is obtained, and 1 is subtracted from this ratio. After the value is obtained using the average value of the multiple values, the wheel difference ratio is obtained as described above using the average values ​​obtained sequentially.

[0107] FIG. 7 shows a graph with the wheel difference ratio thus calculated on the vertical axis and time on the horizontal axis. This graph also shows the steering angle acquired by the control unit 18 in parallel from the OBD2. As is clear from this graph, the wheel difference ratio calculated by averaging multiple instantaneous values ​​of information on the rotational speed of the wheels almost coincides with the steering angle. Furthermore, by using the average value, even if there is a value that is extremely different from the others among the multiple values, it is leveled to a value that is closer to the steering angle.

[0108] (Example of measuring the rotational speed of each wheel during actual driving) In order to show why a direction change can be detected by the wheel difference ratio as described above, Fig. 8 shows data obtained by the control unit 18 measuring and comparing the rotational speed of each wheel when the vehicle simply drives straight through a parking lot, turns right and then drives straight again. The graph in Fig. 8 can also be displayed on the display unit 5 during or after the measurement, based on the data acquired by the control unit 18 and stored in the database 19 as described above.

[0109] FIG. 8(a) is a graph showing vehicle speed. This vehicle speed may be a value obtained from OBD2 or a value based on GPS. One hundredth of the value on the vertical axis indicates the speed in km / h. The value on the horizontal axis indicates seconds. The measurement time is 30.9 seconds.

[0110] FIG. 8(b) is a graph showing the rotational speed of each wheel measured simultaneously with the vehicle speed. The vertical axis shows the instantaneous value of the information on the rotational speed of each wheel. The acquisition timing is approximately every 0.01 seconds. The numbers on the horizontal axis show seconds.

[0111] As shown in Fig. 8(a), the vehicle speed increases from 2.3 to 4.5 seconds after the start of measurement. At this time, the vehicle is moving straight, so the rotational speeds of the wheels are almost the same, as shown in Fig. 8(b). Then, from 4.5 to 23.0 seconds, the vehicle is moving clockwise, so there is a difference in the rotational speed of each wheel. Furthermore, from around 24.3 seconds, as the vehicle speed decreases, the vehicle returns to moving straight, and the rotational speeds of the wheels again match.

[0112] Here, as shown in Fig. 8(b), when the vehicle is traveling clockwise, the inner right front wheel and right rear wheel rotate slowly, and the outer left front wheel and left rear wheel rotate quickly. Also, the left front wheel rotates the fastest, and the right rear wheel rotates the slowest.

[0113] Therefore, in the case of a simple right turn, the wheel difference ratio between the diagonally opposite wheels, the left front wheel and the right rear wheel, will be the largest. In the case of a left turn, it can be easily inferred that the wheel difference ratio between the right front wheel and the left rear wheel will be large. The next largest wheel difference ratios are between the left front wheel and the right front wheel, or between the left rear wheel and the right rear wheel. The wheel difference ratios between the left front wheel and the left rear wheel, or the right front wheel and the right rear wheel, are smaller than the others, but the differences are clearly evident. For example, in FIG. 8(b), the numerical values ​​showing the rotational speeds of each wheel around 10 seconds are 623 for the left front wheel, 576 for the left rear wheel, 507 for the right front wheel, and 457 for the right rear wheel.

[0114] As described above, it is clear that the rotation speeds of the wheels differ when the vehicle changes direction. Therefore, the control unit 18 can detect the direction change by comparing information on the rotation speeds of any two of the wheels.

[0115] [Vehicle abnormal condition detection function] The vehicle abnormality detection function is a function in which the control unit 18 detects slippage of a specific wheel as an abnormal condition of the vehicle based on the relationship of information related to the rotation of at least two different wheels. Note that the control unit 18 can also display the graphs shown below on the display 5 based on the data stored in the database 19 during or after the measurement.

[0116] (Sudden braking on snowy roads) FIG. 9 is a graph showing the slip state when a front-wheel drive vehicle suddenly brakes while driving straight on a snowy road. The vertical axis of FIG. 9(a) shows vehicle speed, and the horizontal axis shows time. Vehicle speed may be a value obtained from OBD2 or a value based on GPS. One hundredth of the value on the vertical axis shows the speed (km / h). The value on the horizontal axis shows seconds. The total measurement time on the horizontal axis is 95 seconds. The vertical axis of FIG. 9(b) shows the instantaneous value of information related to the rotational speed of each wheel measured simultaneously with the vehicle speed. The acquisition timing is approximately 0.01 second intervals. The value on the horizontal axis shows seconds.

[0117] First, as shown in FIG. 9(a), stable driving continues until about 25 seconds after the start of measurement, and the rotation speed of each wheel is almost the same. Then, at about 25 seconds, the brakes are applied hard. If there was no ABS, the wheels would be locked and the rotation speed of the wheels would be almost zero. However, because the ABS is working, the rotation speed of each wheel only drops slightly. The ABS controls each wheel appropriately using a control value. However, as a result, the actual rotation speed of each wheel differs. This is due to differences in the steering angle, road surface condition, and the contact state of each wheel with these, etc.

[0118] For this reason, as shown in Fig. 9(b), the left front wheel has the slowest rotation speed and is slipping the most. Here, when the control unit 18 determines that there is slip based on a threshold value previously set in the database 19, it warns the user by displaying a balloon saying "Left front wheel is slipping" on the graph on the display 5 as shown in Fig. 9(b). The warning display area is an area avoiding the lines showing the data.

[0119] The threshold value may be, for example, when the rotation speed of a specific wheel is reduced by more than one-third of the rotation speed of any of the other wheels. Note that the threshold value for issuing a warning may be determined based on experiments, etc., and it is not necessary to issue a warning every time a difference occurs in the rotation speed of the wheels.

[0120] After this, the brakes are applied continuously from about 25 to 47 seconds. As a result, the vehicle gradually decelerates, as shown in Fig. 9(a). In particular, at about 33 seconds, the right front wheel loses the most rotational speed and is slipping significantly, as shown in Fig. 9(b). At this point, the control unit 18 warns the driver by displaying a balloon saying "Right front wheel is slipping" on the graph on the display 5.

[0121] Then, from 47 to 56 seconds, the brakes are not applied. Therefore, as shown in FIG. 9(a), the vehicle speed drops very gradually. At this time, as shown in FIG. 9(b), the rotational speeds of the wheels are stable and almost the same. Furthermore, at about 56 seconds, the brakes are applied again. This causes the vehicle speed to drop suddenly, as shown in FIG. 9(a).

[0122] At this time, as shown in Fig. 9(b), the right front wheel has the slowest rotation speed and is slipping the most. Here, the control unit 18 warns by displaying a balloon saying "Right front wheel is slipping" on the display 5, superimposed on the graph. Next, the left front wheel also slows down its rotation speed and begins to slip. Here, the control unit 18 warns by displaying a balloon saying "Left front wheel is slipping" on the display 5, superimposed on the graph.

[0123] From around 63 seconds, the rotational speed of each wheel stabilizes and is almost the same. Stable driving continues after that, and from around 70 seconds, the speed gradually increases by stepping on the accelerator without braking.

[0124] (Snowy Road Acceleration 1) Figure 10 is a graph showing the slip state when the accelerator is depressed while driving straight on a snowy road in a front-wheel drive vehicle. In Figure 10(a), the vertical axis 0-6000 rpm indicates engine speed, and the horizontal axis indicates time (seconds). In Figure 10(b), the vertical axis 0-8000 indicates vehicle speed (1 / 100 is speed in km / h), and the horizontal axis indicates time (seconds). In Figure 10(c), the vertical axis indicates the value indicating the rotational speed of each wheel, and the horizontal axis indicates time (seconds), with the total measurement time being 155 seconds.

[0125] As shown in Figure 10(a), when the accelerator is depressed around 3.7 seconds after the start of measurement, the engine speed increases rapidly. At around 11.2 seconds, the accelerator is still depressed, but the rate of increase in engine speed slows down slightly because the vehicle is going up a slope. Following the increase in engine speed at around 3.7 seconds, the vehicle speed increases at around 12 seconds, as shown in Figure 10(b). Note that if the vehicle speed decreases, the engine speed also decreases with a delay.

[0126] Here, at about 12 seconds when the vehicle speed increases, the rotation speed of the left front wheel increases and the wheel starts to slip, and about four seconds later, the rotation speed of the right front wheel increases and the wheel starts to slip, as shown in Fig. 10(c). When the control unit 18 determines that a slip has occurred based on a threshold value preset in the database 19, it warns the user by displaying a speech bubble saying "Left front wheel is slipping" or "Right front wheel is slipping" on the display 5, superimposed on the graph, as shown in Fig. 10(c).

[0127] The threshold value may be when the rotational speed of a specific wheel becomes half or more of the rotational speed of any of the other wheels. The threshold value for braking shall be the same as that for sudden braking on snowy roads described above. The threshold value for the warning may be determined based on experiments, etc., and it is not necessary to issue a warning every time a difference occurs in the rotational speed of the wheels.

[0128] After that, from 23 to 76 seconds, the engine speed fluctuates as shown in Figure 10(a), but this is because the driver is simply stepping on the accelerator in response to the terrain. Therefore, the vehicle speed increases gradually until around 82 seconds as shown in Figure 10(b). Also, the rotation speeds of each wheel are consistent as shown in Figure 10(c).

[0129] Furthermore, as shown in Fig. 10(a), after the accelerator is suddenly depressed at about 76 seconds, the accelerator is continued to be lightly depressed until about 110 seconds. Then, as shown in Fig. 10(b), the vehicle speed increases suddenly at about 82 seconds, then drops once and increases again. At this time, as shown in Fig. 10(c), the speeds of the right and left front wheels increase suddenly and both slip, and while the right front wheel returns to normal, the left front wheel continues to slip, and the right front wheel starts to slip again, and at about 117 seconds, both wheels return to normal.

[0130] At this time, the control unit 18 warns of slippage by displaying speech bubbles saying "Left front wheel is slipping" and "Right front wheel is slipping" on the display 5, superimposed on the graph, as shown in Fig. 10(c). In this way, only the front wheels slip on the left and right because they are the driving wheels. Also, the behavior of the left and right wheels differs because there is a difference in slipperiness, such as when the right is a road and the left is icy.

[0131] Next, as shown in Fig. 10(a), when the accelerator is depressed at about 126 seconds, the engine speed increases suddenly. Later, at about 131 seconds, as shown in Fig. 10(b), the vehicle speed increases slightly, and the left front wheel slips slightly, as shown in Fig. 10(c). However, the control unit 18 does not issue a warning because it considers this level of increase in the engine speed to be a minor slip that does not reach the threshold value.

[0132] Finally, as shown in Fig. 10(a), when the brake is applied at about 151 seconds, the vehicle speed decreases slightly as shown in Fig. 10(b), and the left front wheel slips slightly as shown in Fig. 10(c). Thus, a slip caused by braking appears as a decrease in rotation speed, in contrast to a slip caused by the accelerator. Note that the control unit 18 does not issue a warning because it considers this level of slip to be a minor slip that does not reach the threshold value.

[0133] (Snowy Road Acceleration 2) Like Fig. 10, Fig. 11 is a graph showing the slip state when the accelerator is depressed while driving straight on a snowy road in a front-wheel drive vehicle. However, the measurement time on the horizontal axis is longer than that of Fig. 10, at 321 seconds. In Fig. 10(a), the vertical axis is 0 to 7000 and represents vehicle speed (1 / 100 is speed in km / h), and the horizontal axis is time (seconds). In Fig. 10(b), the vertical axis is the value indicating the rotational speed of each wheel, and the horizontal axis is time (seconds).

[0134] As is clear from this graph, when the accelerator is depressed on a snowy road and the vehicle speed increases suddenly, the rotational speed of the right and left front wheels increases and a slip occurs, just as in Snowy Road Slip 1.

[0135] [4. Effects of the embodiment] According to the present embodiment described above, the following effects can be obtained. (A) By simply connecting to a network that controls the vehicle, the control unit 18 can obtain information regarding changes in the direction of travel. Therefore, for example, it is not necessary to install sensors on multiple different wheels and connect these sensors with wires. This is particularly effective when it is not possible to obtain steering angle, etc. from the network that controls the vehicle, or when the data format, etc. is not publicly available and it is difficult to obtain the information.

[0136] (B) In a configuration in which information regarding a change in the vehicle's traveling direction is obtained by GPS, information regarding a change in the vehicle's traveling direction cannot be obtained in places where GPS radio waves are blocked and positioning is not possible, but the control unit 18 can obtain information regarding the rotation of at least two different wheels to obtain information regarding the change in the vehicle's traveling direction. Note that the control unit 18 may be configured to correct the travel distance obtained by GPS based on the information regarding the change in the vehicle's traveling direction.

[0137] In a vehicle that does not have a steering angle sensor, even if the steering angle sensor is present but has limited use, or even if the steering angle sensor is broken, the control unit 18 can obtain information regarding changes in the vehicle's direction of travel by obtaining signals regarding the rotation of at least two different wheels.

[0138] (C) The resolution of the information on the rotation of the wheels in the network through which the data used to control the vehicle itself flows is 10 to 100 times higher than the vehicle speed (1 km / h steps). This reduces the quantum error, and even when driving at low speeds, the error in the information on the change in the vehicle's traveling direction obtained by the control unit 18 from the information on the rotation of the wheels is extremely small. Therefore, the control unit 18 can obtain information on the change in the traveling direction with a level of accuracy that is comparable to that of a steering angle sensor.

[0139] The control unit 18 can calculate the vehicle speed and distance traveled from information about the rotation of the wheels in the network through which data used to control the vehicle itself flows, together with information about changes in the vehicle's direction of travel, and can also calculate the gear ratio from the engine speed and vehicle speed obtained separately. In this way, errors in the calculated vehicle speed, distance traveled, gear ratio, etc. can also be reduced.

[0140] (D) The network provided in the vehicle is a wired network. Therefore, the control unit 18 can obtain information about a change in the vehicle's traveling direction simply by connecting to one of the signal lines (for example, a group of signal lines) of the network with a wire. In particular, the connection is easy because the control unit 18 is configured to connect to a detachable connector of the signal line of the network.

[0141] (E) By using information corresponding to only two wheels, the control unit 18 processes a smaller amount of information, which simplifies and speeds up processing. Also, the control unit 18 obtains instantaneous values ​​of information relating to the rotation of at least two wheels at approximately the same time from the network every 10 ms and uses the obtained information. Therefore, the information is sufficient for the control unit 18 to obtain information relating to changes in the traveling direction of the vehicle.

[0142] (F) The control unit 18 does not collect information by querying devices connected to the network, but reads information flowing through the network, so stress on devices connected to the network can be avoided. In particular, the computer that outputs information about wheel rotation to the network does not need to respond to queries, so stress can be avoided. Moreover, since there is no increase in network traffic, stress on the overall control of the vehicle can also be avoided.

[0143] (G) The control unit 18 displays on the display screen of the display device 5 the information on the steering wheel angle acquired from the network and the information on the steering wheel angle calculated based on the relationship between the information on the rotations of two different wheels. Therefore, the passengers of the vehicle, including the driver, who are viewing the display screen, can compare the information on the steering wheel angle acquired from the network that controls the vehicle with the information on the steering wheel angle calculated based on the relationship between the information on the rotations of two different wheels. The passengers of the vehicle who compare the two pieces of information on the steering wheel angle in this way can determine the direction change or abnormal state of the vehicle from the degree of difference between the two pieces of information, etc.

[0144] Furthermore, since the abnormal state of the vehicle is displayed on the display screen of the display device 5, the vehicle occupants, including the driver, can easily recognize the abnormal state of the vehicle without the trouble of determining the abnormal state by themselves. For example, the control unit 18 can make the vehicle occupants recognize the slip by displaying a warning notifying the occurrence of a slip in a speech bubble superimposed on a graph. The control unit 18 can prevent the data from becoming difficult to see by setting the warning display area to an area that avoids the lines indicating the data. Furthermore, the control unit 18 can prevent the warning from being displayed frequently, which makes it difficult to recognize the danger, by not issuing a warning for minor slips.

[0145] Furthermore, vehicle occupants, including the driver, who look at the display screen can recognize changes in the vehicle's direction of travel and determine the driving condition of the vehicle based on these changes in the vehicle's direction of travel, which can be useful for safe and eco-friendly driving.

[0146] (H) The control unit 18 uses the signal from the sensor used in the ABS (antilock braking system), which saves the effort and cost of adding a special sensor. Also, the information based on the signal from the sensor used in the ABS has a higher resolution than the vehicle speed sensor of the transmission, so the direction can be detected accurately.

[0147] Furthermore, even if the information on wheel rotation acquired by the control unit 18 from the network includes a value that is significantly different from the others among the multiple values, the value is not used as is, but the average value of the multiple values ​​is used, so that it can be leveled to a value that is closer to the steering angle. Therefore, it is possible to detect the direction with higher accuracy, closer to that of a steering angle sensor.

[0148] 5. Other embodiments The present invention is not limited to the above-described embodiments. (a) "Information regarding wheel rotation" may be the amount of rotation of the wheel per unit time, the number of rotations of the wheel per unit time, or the rotation angle of the wheel per unit time. This information also indicates different values ​​for each wheel when the vehicle changes direction or an abnormal driving state occurs, so that the control unit 18 can detect the direction change or abnormal state, as in the above embodiment.

[0149] (b) The "network for controlling the vehicle" may be a network outside the vehicle. The network may be wired or wireless. For example, by acquiring information about wheel rotation from a network outside the vehicle that collects data while the vehicle is running, a person outside the vehicle can compare information about the steering angle acquired from the network for controlling the vehicle with information about the steering angle calculated based on the relationship between information about the rotation of two different wheels. In this case, the display screen may be a display screen on a display device of a computer installed outside the vehicle and connected to the network.

[0150] In this way, a person outside the vehicle who compares both pieces of information related to the steering wheel angle can recognize the direction change or an abnormal state of the vehicle from the degree of difference between the two pieces of information. Also, by displaying the abnormal state of the vehicle on the display screen as described above, a person outside the vehicle can easily recognize the abnormal state of the vehicle without the trouble of determining the abnormal state by himself. Furthermore, a person outside the vehicle who sees the display screen can recognize the change in the traveling direction of the vehicle and determine the driving state of the vehicle based on this change in the traveling direction of the vehicle, which can be useful for safe driving and eco-driving.

[0151] For example, a taxi company or a transportation company may check the past or present changes in the traveling direction of the driver's vehicle on a display screen installed in the company, determine what the driving condition is, and use the results as an index to encourage the driver to drive safely and eco-friendly. Also, for example, a driver may check the past changes in the traveling direction of his / her own vehicle on a display screen at home, determine what the driving condition was, and use the results as an index to aim for safe driving and eco-friendly driving. In this case, as described above, a computer outside the vehicle may obtain information via a network and display it on the display screen, or information may be recorded on a memory card 11 inserted in a system installed in the vehicle, and the memory card 11 may be read by a computer outside the vehicle to display the information on the display screen.

[0152] (c) The "at least two different wheels" that are the subject of the information on rotation may be two or more. For example, of the information corresponding to the two wheels and the information corresponding to the other two wheels, the one that shows a normal value may be used, or the average of both pieces of information may be used. In this way, highly accurate detection is possible. As described above, the information on the wheels may include a time that shows a value that is extremely different from the others among multiple values. However, the control unit 18 can eliminate or average such values ​​by determining a normal value or an average value and using it for detection.

[0153] (d) The "information regarding a change in the vehicle's traveling direction" may be, for example, information indicating the degree of difference between information regarding the rotation of at least two wheels. For example, it may be information based on the difference between values ​​indicated by the information regarding the rotation of the two wheels. Also, for example, it may be information based on the ratio of values ​​indicated by the information regarding the rotation of the two wheels. Such information also provides values ​​that differ depending on the traveling direction, so that the control unit 18 can detect a change in the traveling direction.

[0154] The control unit 18 may detect only a right or left turn at a branch point, for example. In this way, the control unit 18 judges fewer directions, and processing can be simplified and accelerated. The change in the direction of travel may be a change in the angle of travel or a change in the steering wheel angle. Since the present system is capable of detection with the same accuracy as the steering wheel angle, it can detect even detailed changes in the direction of travel. In this way, the control unit 18 can determine a more detailed driving state. For example, the control unit 18 can detect a change in the direction of travel in the same lane, and a change in the direction of travel when changing lanes. Furthermore, even if GPS positioning is not possible, the control unit 18 can detect a change in the direction of travel at a curve in a road at an intersection, underground, or in a tunnel.

[0155] (e) Although the information on the steering wheel angle acquired from the network accurately indicates the steering wheel angle, the information on the steering wheel angle obtained based on the relationship of the information on the rotation of at least two different wheels may differ from the actual steering wheel angle depending on the state of the vehicle. For this reason, the control unit 18 can also detect an abnormal state of the vehicle based on the relationship in which the two pieces of information significantly differ, such as by a threshold value set in advance in the database 19 or more.

[0156] The method of calculating the steering angle based on the relationship of the information on the rotation of the wheels may be as follows. First, the control unit 18 creates a log in which the steering angle at approximately the same time and the information on the rotation of at least two different wheels are acquired at a time interval required to generate information on the change in the traveling direction of the vehicle according to the application, and stores the log in the database 19. The control unit 18 calculates a function of the relationship between the information on the rotation of at least two different wheels of the vehicle in the log and the steering angle at the same time, and calculates the steering angle based on the relationship of the information on the rotation of the wheels using the function. For example, the control unit 18 stores in the database 19 a log in which the difference or ratio between the instantaneous values ​​of the rotation speeds of two different wheels at the same time are associated with the steering angle at the time, and stores the correlation between the difference or ratio and the steering angle in the database 19 as a function. The function may be incorporated into the program as a formula, or a table for calculating the mapping may be created and stored, and the program may be configured to perform calculations using the table. The database 19 may store such a program created based on past information in advance, and the control unit 18 may be configured to operate based on the program.

[0157] The data format of the information on wheel rotation and the steering wheel angle flowing through the network may differ for each vehicle model. The correspondence between the information on wheel rotation and the steering wheel angle is obtained in advance for each vehicle model, a function is calculated, and the function is stored in the database 19 as a program or data. The system is provided with a function for the control unit 18 to set the vehicle model by automatic detection or for the user to set it manually. The control unit 18 calculates the correspondence between the set vehicle model and the information on wheel rotation and the steering wheel angle. The control unit 18 can detect an abnormal state of the vehicle, such as a flat tire or a slip, based on the relationship between the steering wheel angle calculated in this way and the steering wheel angle acquired from the network. This allows accurate detection even if the vehicle model is different.

[0158] (f) By detecting an abnormal condition of the vehicle when the rotation speed of a particular wheel is significantly different from that of the other wheels, the control unit 18 can detect not only slippage of a particular wheel on snowy, icy or muddy roads, but also abnormal traction, punctures and abnormal tire pressure.

[0159] (g) The mode in which the control unit 18 displays the information on the rotation of the wheels on the display 5 may be any mode that allows, for example, identification of the difference between the information on the steering wheel angle acquired from the network that controls the vehicle and the information on the steering wheel angle obtained based on the relationship between the information on the rotation of at least two different wheels. It is preferable to display the existence of a difference between the two pieces of information, the magnitude of the difference, or the type of abnormality estimated from the difference. In this way, the direction change or abnormal state of the vehicle can be easily determined.

[0160] The display of information regarding the change in the vehicle's traveling direction may be, for example, a display in a manner that allows the driving state of the vehicle to be determined from the presence or absence of a change in the traveling direction. For example, the display may be a manner that allows the driver to visually grasp the instantaneous change in the traveling direction of the vehicle. This may be a symbolic display such as an arrow on the display screen, or light emitted by lamps such as LEDs arranged on the left and right.

[0161] The manner of displaying the abnormal state may be, for example, a display that allows recognition of a flat tire, abnormal air pressure, slippage of a specific tire, etc., by characters, figures, colors, or changes therein. Display on a display screen or illumination by a lamp such as an LED may also be used.

[0162] Furthermore, the display may be arranged to allow visual recognition of all changes in the vehicle's direction of travel over a given period of time, for example, a period of time that allows determination of repeated lane changes in a short period of time, frequent changes in direction of travel within the same lane, etc.

[0163] The driving state of the vehicle determined by the vehicle occupant or a person outside the vehicle may be, for example, a driving state that is compatible with or contrary to safe driving or eco-driving. In this way, for example, it can be linked to the realization of safe driving or eco-driving by the driver of the vehicle. For example, repeated lane changes in a short period of time may be determined by the vehicle occupant or a person outside the vehicle as a driving state of frequent overtaking. For example, frequent changes in the direction of travel within the same lane may be determined by the vehicle occupant or a person outside the vehicle as a driving state of drunk driving or drowsy driving.

[0164] As a display that can determine the driving condition, it is preferable to display, for example, a graph showing the change in the direction of travel or the steering angle over a specified period of time, or numbers showing the frequency of change in the direction of travel or the steering angle over a specified period of time.

[0165] (h) The control unit 18 may determine the driving state of the vehicle based on the information regarding the change in the traveling direction of the vehicle as described above, and may control the display device 5 to display the driving state on the display screen. In this way, the vehicle occupants including the driver or persons outside the vehicle who view the display screen can easily recognize the driving state of the vehicle without the trouble of determining the driving state themselves. The display of the driving state may be, for example, a display that can be recognized by characters, figures, colors, or changes in these, such as danger, safety, drowsiness, drinking, etc.

[0166] (i) The control unit 18 may obtain information related to the driving operation of the vehicle via the network, and may perform control to display the obtained information related to the driving operation of the vehicle together with information related to a change in the traveling direction of the vehicle on the display screen of the display device 5. In this way, since the information related to the driving operation of the vehicle is displayed together with the information related to the change in the traveling direction of the vehicle, passengers of the vehicle including the driver or a person outside the vehicle who sees the display screen can determine the driving state of the vehicle in more detail based on the relationship between the change in the traveling direction and the information related to the driving operation.

[0167] The information on the driving operation of the vehicle may be, for example, information indicating the occurrence of an operation of a member or mechanism that is required to be operated by the driver while driving, and the timing of the operation. For example, the information on the driving operation of the vehicle may be information such as when the turn signal was turned on, when and how many times the brake was applied, and when and how many times the accelerator was applied. For example, if the turn signal is not turned on before turning right or left, it may be determined that the driving state is dangerous. For example, if the brake is not applied before turning right or left, or the accelerator is applied, it may be determined that the driving state is dangerous.

[0168] (j) The control unit 18 may acquire information regarding the driving operation of the vehicle, determine the driving state of the vehicle based on the acquired information regarding the driving operation of the vehicle and information regarding a change in the traveling direction of the vehicle, and perform control to display the driving state on the display screen of the display device 5. In this way, passengers of the vehicle including the driver or persons outside the vehicle who view the display screen can easily obtain detailed driving states without the hassle of determining the driving state themselves.

[0169] (k) The control unit 18 may control the speaker 16 to output a sound in response to an abnormal state or driving state. In this way, by outputting a sound, the vehicle occupants or outsiders who are not looking at the display screen can be reliably notified of an abnormal state of the vehicle. For example, a flat tire, an abnormal air pressure, slippage of a specific tire, etc. can be made known to the vehicle occupants or outsiders. In addition, by outputting a sound, the vehicle occupants or outsiders who are not looking at the display screen can be reliably notified of the driving state of the vehicle. For example, the vehicle occupants or outsiders can be warned of the dangers of drowsy driving or drunk driving.

[0170] (l) In judging whether a value is greater than or less than a threshold value for detecting right / left turns or abnormal conditions, or in judging whether a value matches or does not match a threshold value, it is up to the discretion of the judge to use terms such as "greater than" and "less than" or to use terms such as "greater than," "more than," "exceeds," "does not exceed," "above," "below," and "less than" to essentially the same effect, depending on the value settings.

[0171] (m) The control unit 18 may be set not to detect the vehicle's traveling direction when the ABS function is activated. When the ABS is activated, the traveling direction cannot be accurately detected using the signal from the sensor, so by having the control unit 18 not detect the direction in such a case, it is possible to prevent erroneous judgments and erroneous operations due to erroneous detection.

[0172] (n) The control means may be realized by one control unit 18 or by multiple control units 18. The control unit 18 may be entirely provided inside the vehicle, entirely provided outside the vehicle, or part of the control unit 18 may be provided inside the vehicle and the remaining part may be provided outside the vehicle. A system may be provided in which at least part of the functions of the control unit 18 are provided in a server, the server executes the functions, and the electronic device held by the user acquires the execution results. Also, a part or all of the information to be registered in the database may be registered in the server. A radar detector or other electronic device / apparatus may have a function of communicating with the server, and the control unit may access the server as appropriate, acquire necessary information, and execute processing.

[0173] (o) The display 5 as a display means may be any display device such as a liquid crystal, organic electroluminescence (EL) display screen, etc., as long as it can display something that can be visually recognized by the user, etc. Such a display means may be realized by a display device of a computer installed outside the vehicle and connected to a network, as described above. The speaker 16 (including headphones, earphones, etc.) as a sound output means may also be realized by an output device of a computer installed outside the vehicle and connected to a network.

[0174] (p) The system to which the present invention is applied is not limited to the radar detector 1. The present invention can be applied to various types of in-vehicle electronic devices, such as car navigation systems and drive recorders. The functions of the present invention can be easily added by installing a program in an existing system configured as an electronic device. Therefore, vehicle owners can use new functions while keeping expenses down.

[0175] (q) The functions of the system of the present invention are configured as a program to be realized by a computer provided in the control unit 18, but the present invention is not limited to this and the program may be distributed among multiple computers for distributed processing. [Explanation of symbols]

[0176] 1. Radar detector 2. Case body 3…Bracket 5...Indicator 6. Touch panel 7...Volume adjustment button 8…Operation buttons 10. Memory card reader 11. Memory card 12…DC jack 13…GPS receiver 14...Microwave receiver 15...Radio receiver 16…Speaker 18...Control section 19. Database 22…Connection cable 23…Plug 25…Connector terminal 24...Socket 31...Lamp 32...Remote control receiver 33…Remote control 34...Infrared communication device 35...Mobile phone 36...Geomagnetic sensor 37…Accelerometer 111…Car icon 112…Target icon 121…Current time 122…GPS signal reception level icon 123...No parking area icon 124…Reception sensitivity mode display icon 125…Vehicle speed 126…Compass needle 130,131…GPS alarm display

Claims

1. A system having a function of acquiring information regarding wheel rotation from an external network that collects data while the vehicle is traveling, and displaying the information on a display screen of a display device of a computer installed outside the vehicle and connected to the network, so that a person outside the vehicle can compare information regarding steering angle acquired from a network that controls the vehicle with information regarding steering angle obtained based on the relationship between information regarding the rotation of at least two different wheels.

2. The system according to claim 1, further comprising a function for making the display manner capable of identifying a difference between information regarding a steering wheel angle obtained from a network that controls the vehicle and information regarding a steering wheel angle obtained based on a relationship between information regarding the rotation of the at least two different wheels.

3. The system according to claim 2 , further comprising a function for displaying the presence of the difference as a mode for identifying the difference.

4. 4. The system according to claim 2, further comprising a function of displaying the magnitude of the difference as a mode for enabling the difference to be identified.

5. The system according to claim 2 , further comprising a function for displaying a type of abnormality estimated from the difference, as a mode for identifying the difference.

6. 6. The system according to claim 1, further comprising a function of displaying on said display screen a change in the traveling direction of said vehicle so that the change can be recognized.

7. 7. The system according to claim 1, wherein the display screen is installed in a taxi company or a transportation company.

8. A program for causing a computer to realize the functions of the system according to any one of claims 1 to 7.

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