JP2023175899A - System and program - Google Patents

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

The present invention relates to a system and a program for obtaining information regarding, for example, changes in the direction of travel of a vehicle.

In-vehicle electronic devices such as navigation devices and radar detectors measure the position of the vehicle based on signals obtained by a GPS receiver 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 built-up area, under an overpass, etc.

For this reason, when in-vehicle electronic equipment cannot receive GPS radio waves, it calculates the vehicle's traveling direction, inclination, distance traveled, etc. based on signals from the vehicle's gyro sensor, acceleration sensor, vehicle speed sensor, etc. , the vehicle's position is being corrected.

However, it is more accurate to determine the direction of travel of the vehicle from the signal from the steering angle sensor that detects the steering angle of the steering wheel. Therefore, as disclosed in Patent Document 1, if the vehicle is equipped with a steering angle sensor, a change in the traveling direction of the vehicle can be accurately detected by acquiring a signal from the steering angle sensor.

Japanese Patent Application Publication No. 7-35566

However, not all vehicles are equipped with a steering angle sensor, and many vehicles do not have a steering angle sensor. Furthermore, even if the vehicle is equipped with a steering angle sensor, it may not be possible to obtain a steering wheel angle signal from the steering angle sensor from a 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.

Patent Document 1 also describes detecting the traveling direction of the vehicle by detecting the inner wheel difference or the outer wheel difference without using such a steering angle sensor. Furthermore, this document describes that left and right vehicle speed sensors are arranged, and the amount of displacement in direction is calculated by detecting the turning of the vehicle based on the difference in output pulses (difference in moving distance).

However, to create such a configuration, it is necessary to install new vehicle speed sensors for multiple different wheels and connect each of those vehicle speed sensors to the system via wires, which takes time and effort to install. and is costly.

Furthermore, conventional general vehicle speed sensors can only output a signal of about 2 to 8 pulses per revolution, so high resolution cannot be obtained. For this reason, even if a vehicle speed sensor is used, it will only be accurate enough to detect left or right turns of the vehicle, and will not be as accurate as a steering angle sensor.

Therefore, for example, a change in direction cannot be detected at a branch point where the angle is not large. Further, for example, when getting off an expressway, it is not possible to detect a situation where the vehicle descends diagonally to the main road. Furthermore, for example, it is not possible to detect a change in direction when changing lanes or a change in direction within the same lane.

The present invention was proposed to solve the above-mentioned problems, and eliminates the trouble and cost of installing sensors on a plurality of different wheels and connecting wires to each wheel, and allows steering wheel control from a steering angle sensor. It is an object of the present invention to provide a system etc. that can obtain information regarding a change in the traveling direction of a vehicle even when the angle cannot be obtained.

In order to achieve the above objectives, the system of the present invention includes:
(1) Information regarding the rotation of the wheels of the vehicle is acquired from a network that controls the vehicle, and information regarding changes in the traveling direction of the vehicle is obtained based on the relationship of the acquired information regarding the rotation of at least two different wheels. It is characterized by seeking.

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, there is no need to install sensors on a plurality of different wheels and connect them with wires. This is particularly effective in cases where it is not possible to obtain the steering wheel angle, etc. from a network that controls the vehicle, or where the data format, etc. is not disclosed and is difficult to obtain.

For example, in a configuration that uses GPS to obtain information regarding changes in the vehicle's traveling direction, information regarding changes in the vehicle's traveling direction cannot be obtained in places where GPS radio waves are blocked and positioning cannot be performed. By obtaining information regarding the rotation of the different wheels, information regarding changes in the direction of travel of the vehicle can be determined. For example, a configuration may be provided that corrects the travel distance determined by GPS based on information regarding a change in the direction of travel of the vehicle. Furthermore, in the case of vehicles without a steering angle sensor, if there is a steering angle sensor but its use is limited, or even if the steering angle sensor is faulty, at least two different signals relating to the rotation of the wheels can be used. By obtaining the information, it is possible to obtain information regarding changes in the direction of travel of the vehicle.

The information regarding the rotation of the wheel may be, for example, the amount of rotation of the wheel per unit time, such as the number of rotations of the wheel per unit time, or the rotation angle of the wheel per unit time. Further, as information regarding the rotation of the wheels, it is preferable to read information sent to the network at predetermined time intervals, particularly in order to control the vehicle. Further, as the information regarding the rotation of the wheels, for example, information from a sensor installed at each wheel of an existing vehicle and outputting information according to the rotation of the wheel may be used. In this case, for example, the user can easily connect and use the network as an afterthought.

The network for controlling the vehicle may be, for example, a network outside the vehicle, but it is particularly preferable to use a network provided in the vehicle. In particular, it is preferable to use a network through which data used to control the vehicle itself flows. In particular, it is preferable to use a network to which a plurality of computers for controlling the vehicle are connected, such as CAN. The resolution of information regarding wheel rotation in the network that carries data used to control the vehicle itself is 10 to 100 times higher than the vehicle speed (1 km/h step), so quantum errors are small, and even when driving at low speeds, Even at the same time, the error in information regarding changes in the direction of travel of the vehicle determined from information regarding wheel rotation is also extremely small. Therefore, it is possible to obtain information regarding changes in the direction of travel accurately, comparable to, for example, a steering angle sensor.

In addition, for example, from information regarding the rotation of wheels in the network through which data used to control the vehicle itself flows, information regarding changes in the direction of travel of the vehicle can be used to calculate vehicle speed, travel distance, etc. It is preferable to use a configuration in which the gear ratio is calculated from the engine rotational speed and vehicle speed, but errors in these vehicle speeds, travel distances, gear ratios, etc. can also be reduced.

Further, 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 changes in the traveling direction of the vehicle can be obtained by simply connecting a wire to one point of the signal line (for example, a group of signal lines) of the network. In particular, it is preferable to connect to a connector that is detachable from a network signal line. For example, it may be configured to include a plug that connects to a connector having a network signal line, such as a fault diagnosis connector provided in a vehicle.

Examples of two different wheels include, in the case of a four-wheeled vehicle, left and right front wheels, left and right rear wheels, left front wheel and left rear wheel, right front wheel and right rear wheel. , the front left wheel and the rear right wheel, or the front right wheel and the rear left wheel.

"At least two" is preferably 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, making it possible to simplify and speed up the processing. Furthermore, for example, out of the information corresponding to the two wheels and the information corresponding to the other two wheels, the one showing a normal value may be used, or the average of both pieces of information may be used. In this way, for example, highly accurate detection becomes possible.

Information regarding the rotation of wheels included in a vehicle may be acquired from a network that controls the vehicle, for example, at predetermined intervals. The predetermined time may be, for example, a time required to obtain information regarding a change in the direction of travel of the vehicle. For example, it may be an instantaneous value of information regarding the rotation of at least two wheels at approximately the same time.

The information regarding the change in the traveling direction of the vehicle may be, for example, information indicating the degree of difference between the information regarding the rotation of at least two wheels. For example, the information may be based on the difference between values indicated by information regarding the rotation of two wheels. Further, for example, the information may be based on a ratio of values indicated by information regarding the rotation of two wheels.

The change in direction of travel may be, for example, a right or left turn at a fork. In this way, for example, the number of directions to be determined is reduced, making it possible to simplify and speed up the processing. Further, the change in the traveling direction may be, for example, a change in the traveling angle or a change in the steering angle of the steering wheel. In this way, for example, more detailed driving conditions can be determined. For example, changes in the direction of travel in the same lane and changes in direction of travel when changing lanes can be detected. Furthermore, even if GPS positioning is not possible, changes in the direction of travel at road curves such as at grade crossings, underground, and in tunnels can be detected.

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

The information regarding the steering wheel angle obtained from the network accurately indicates the steering wheel angle, but the information regarding the steering wheel angle obtained based on the relationship between the information regarding the rotation of at least two different wheels may vary depending on the state of the vehicle. There will be a difference from the actual steering angle. Therefore, for example, an abnormal state of the vehicle can be detected based on a relationship such that both pieces of information are significantly different. For example, the following method may be used to determine the steering angle of the steering wheel based on the relationship between the information regarding the rotation of the wheels. First, a log of information regarding the steering wheel angle at approximately the same time and the rotation of at least two different wheels is acquired at the necessary time intervals to generate information regarding changes in the vehicle's direction of travel depending on the application. This system uses this function to determine the relationship between 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. It is better to find the steering wheel angle based on the relationship of the information. For example, the difference or ratio of the instantaneous values of the rotation speeds of two different wheels at the same time and the steering wheel angle at that time are stored as a log in association with each other, and the correlation between this difference or ratio and the steering angle is is stored as a function. The function may be incorporated into the program as a mathematical formula, or, for example, a table for calculating a mapping may be created and stored, and the function may be configured as a program that performs calculations using this table.

For example, the data format of information regarding wheel rotation and steering wheel angle flowing through the network may differ depending on the vehicle model. For example, the correspondence between information regarding wheel rotation and steering angle can be determined in advance for each vehicle model, a function determined and stored as a program or data in this system. It is preferable to provide a function to be set by the user and to obtain the correspondence between the set vehicle types. For example, it is preferable to detect an abnormal state of the vehicle such as a tire blowout or slippage based on the relationship between the obtained steering wheel angle and the steering wheel angle obtained from the network.

The abnormal state of the vehicle may be, for example, a state in which the rotational speed of a particular tire is significantly different from that of other tires. For example, the abnormal state of the vehicle may be a puncture, an abnormality in air pressure, a slip of a specific tire on a snowy road, an icy road, a muddy road, or the like.

(3) It is preferable that information flowing through the network is read without interrogating a device connected to a network provided in the vehicle as a network for controlling the vehicle.

In this way, the information flowing through the network is read without collecting information by asking the devices connected to the network, thereby avoiding stress on the devices connected to the network. In particular, the computer that outputs information about the rotation of the wheels to the network does not have to respond to questions, so stress can be avoided. Furthermore, since network traffic does not increase, stress on the overall control of the vehicle can be avoided.

(4) Display on the display screen information regarding the steering wheel angle obtained from the network that controls the vehicle and information regarding the steering wheel angle obtained based on the relationship between the information regarding the rotation of the at least two different wheels. It is preferable to perform control such that the

In this way, a vehicle occupant including the driver or a person outside the vehicle who views the display screen can receive information regarding the steering wheel angle obtained from the network that controls the vehicle and the at least two different information. It is possible to compare the information regarding the steering angle obtained based on the relationship between the information regarding the rotation of the wheels. A passenger of the vehicle or a person outside the vehicle who has compared both pieces of information regarding the steering wheel angle in this manner can determine the abnormal state of the vehicle based on, for example, the degree of difference between the pieces of information.

The display mode may, for example, indicate the difference between the information regarding the steering wheel angle obtained from the network that controls the vehicle and the information regarding the steering wheel angle obtained based on the relationship between the information regarding the rotation of at least two different wheels. It is preferable to use a form that allows identification. For example, 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 abnormal state of the vehicle can be easily determined.

The display screen may, for example, be capable of visually recognizable display. For example, it may be a display screen installed inside a car. In this way, for example, the passenger of the vehicle who views the display screen can compare both pieces of information. Further, for example, it may be a display screen installed outside the vehicle. In this way, for example, someone outside the vehicle can compare both pieces of information.

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

In this way, since the abnormal state of the vehicle is displayed on the display screen, there is no need for the occupants of the vehicle including the driver or those outside the vehicle to judge the abnormal state by themselves. can be easily recognized.
The display of abnormal conditions may be, for example, a flat tire, abnormal air pressure, slippage of a particular tire, etc., which can be recognized by letters, graphics, colors, or changes thereof.

(6) It is preferable that control is performed to display information regarding a change in the traveling direction of the vehicle on a display screen.

In this way, the vehicle occupants including the driver or those outside the vehicle who view the display screen can recognize the change in the traveling direction of the vehicle. Based on this change in the direction of travel of the vehicle, passengers of the vehicle including the driver or persons outside the vehicle can determine the driving state of the vehicle, which can be useful for safe driving and eco-driving.

The display screen may be, for example, a display screen installed inside the vehicle. In this way, for example, a passenger of the vehicle can recognize a change in the traveling direction of the vehicle. Further, for example, it may be a display screen installed outside the vehicle. In this way, for example, a person outside the vehicle can recognize a change in the traveling direction of the vehicle. For example, in a taxi company or a transportation company, a display screen installed in the company can be used to check changes in the direction of travel of a driver's vehicle in the past or present, and determine the driving condition of the driver. It is good to use this as an indicator to encourage safe and eco-driving. Also, for example, a driver can check past changes in the direction of travel of his or her vehicle on a display screen at home, determine the driving condition, and improve his/her own safe and eco-friendly driving. It is a good idea to use this as an indicator to aim for.

The information regarding the change in the traveling direction of the vehicle may be displayed in a manner that allows the driving state of the vehicle to be determined based on the presence or absence of a change in the traveling direction, for example. For example, a mode may be adopted in which instantaneous changes in the traveling direction of the vehicle can be visually grasped. Furthermore, it is preferable that changes in the traveling direction of the vehicle over a predetermined period of time can be collectively grasped visually. The predetermined period may be set to a period that allows it to be determined, for example, that the vehicle is repeatedly changing lanes in a short period of time, or that the direction of travel is frequently changing within the same lane. The driving state of the vehicle determined by a passenger of the vehicle 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 is possible to realize safe driving and eco-driving for vehicle drivers. For example, repeatedly changing lanes in a short period of time may be determined by the vehicle occupant or a person outside the vehicle as a driving state in which passing is frequently performed. For example, frequent changes in the direction of travel within the same lane may be determined by a vehicle occupant or a person outside the vehicle as a driving state such as drunk driving or drowsy driving. Examples of display modes that allow the driving state to be determined include graphs showing changes in the direction of travel or steering wheel angle over a predetermined period of time, numbers indicating the frequency of changes in the direction of travel or steering wheel angle over a predetermined period, etc. It is good to do this.

(7) It is preferable that the driving state of the vehicle is determined based on the information regarding the change in the traveling direction of the vehicle, and the driving state is controlled to be displayed on the display screen.

In this way, the driving condition of the vehicle is displayed on the display screen, so there is no need for the occupants of the vehicle, including the driver, or those outside the vehicle, who see the display screen, to judge the driving condition by themselves. , the driving condition of the vehicle can be easily recognized.

The display of the driving state may be, for example, a display that can recognize danger, safety, drowsiness, alcohol consumption, etc. using letters, figures, colors, or changes thereof.

(8) It is preferable that information regarding the driving operation of the vehicle is acquired, and the acquired information regarding the driving operation of the vehicle is controlled to be displayed on the display screen along with a change in the traveling direction of the vehicle.

In this way, information related to vehicle driving operations is displayed together with information related to changes in the direction of travel of the vehicle, so that vehicle occupants including the driver who viewed the display screen, or persons outside the vehicle, can easily understand the direction of travel. The driving state of the vehicle can be determined in more detail based on the relationship between the change in the information on the driving operation and the information on the driving operation.

The information regarding the driving operation of the vehicle may be, for example, information indicating that the driver has operated a member or mechanism that is required to be operated while driving, and the timing thereof. For example, information regarding the driving operation of the vehicle may be information such as when the turn signal was activated, when and how many times the brake was pressed, and when and how many times the accelerator was pressed.

For example, if the turn signal is not activated before making a right or left turn, it may be determined that the driving condition is dangerous. For example, if the brake is not pressed or the accelerator is pressed before making a right or left turn, it may be determined that the driving condition is dangerous.

(9) Obtain information regarding the driving operation of the vehicle, determine the driving condition of the vehicle based on the acquired information regarding the driving operation of the vehicle, and changes in the direction of travel of the vehicle, and display the driving condition on the screen It is preferable to use a mode in which control is performed such that the display is displayed in

In this way, the display screen displays the driving state determined by taking into account not only the change in the direction of travel of the vehicle but also information regarding the driving operation of the vehicle, so that the display screen includes the driver who viewed the display screen. A passenger of the vehicle or a person outside the vehicle can easily obtain detailed driving conditions without the trouble of determining the driving conditions by themselves.

(10) It is preferable to adopt a mode in which control is performed to output a sound depending on the abnormal state.

In this way, by outputting the sound, the abnormal state of the vehicle can be reliably notified even to the occupants of the vehicle who are not looking at the display screen or to those outside the vehicle. For example, it is possible to make a passenger of the vehicle or a person outside the vehicle aware of a puncture, abnormal air pressure, slippage of a particular tire, etc.

(11) It is preferable to adopt a mode in which control is performed to output sound depending on the operating state.

In this way, by outputting the sound, it is possible to reliably notify even the vehicle occupants or outsiders who are not looking at the display screen about the vehicle operating state. For example, it is possible to warn a vehicle occupant or a person outside the vehicle of the dangers associated with drowsy driving or drunk driving.

(12) A value indicating the relationship of information regarding the rotation of the at least two different wheels at the same time is used as one value, and the average value of a plurality of consecutive predetermined values is used to determine the change in the traveling direction of the vehicle. It is best to use the mode of requesting information.

In this way, even if there is a value that is extremely different from the others among multiple values, the average value of the multiple values is used instead of using that value as is, so the steering angle can be improved. is leveled to a value close to . Therefore, the direction can be detected closer and more accurately by the steering angle sensor.

The average value of multiple consecutive values can be calculated sequentially by, for example, using the average value of multiple values, and then calculating the average value by excluding the oldest value and including the next value. It is best to use the calculated average value.

(13) The information regarding the rotation of the wheels included in the vehicle may be information based on a signal from a sensor that detects the rotation status of the wheels used in ABS.

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

(14) When the ABS function is activated, the direction of movement of the vehicle may not be detected.

When the ABS is working, it is impossible to accurately detect the direction of travel using signals from the sensor, so by not detecting it, it is possible to prevent erroneous judgments and erroneous operations due to erroneous detection.

(15) The system functions of (1) to (14) can be configured as a program to be realized by a computer.

According to the present invention, the effort and cost of installing sensors on a plurality of different wheels and connecting wires to each wheel is not required, and even when it is not possible to obtain the steering wheel angle from the steering angle sensor, the progress of the vehicle can be improved. Information regarding changes in direction can be determined.

1 is a diagram showing the configuration of a radar detector that is a preferred embodiment of the present invention. FIG. 2 is a block diagram of a radar detector. It is an explanatory diagram showing an example of a standby screen. It is an explanatory view showing an example of a warning screen. FIG. 2 is an explanatory diagram showing an example of a route actually traveled by a vehicle. FIG. 6 is an explanatory diagram showing the steering wheel angle and wheel difference ratio when the vehicle travels along the route shown in FIG. 5 . 6 is an explanatory diagram showing the steering wheel angle and the averaged wheel difference ratio when the vehicle travels along the route shown in FIG. 5. FIG. They are explanatory drawing (a) which shows the vehicle speed when a vehicle runs clockwise, and explanatory drawing (b) which shows the rotational speed of each wheel. They are an explanatory diagram (a) showing the vehicle speed when the brake is applied while the vehicle is traveling straight on a snowy road, and an explanatory diagram (b) showing the rotational speed of each wheel. They are an explanatory diagram (a) showing the engine speed when the accelerator is pressed while the vehicle is traveling straight on a snowy road, an explanatory diagram (b) showing the vehicle speed, and an explanatory diagram (c) showing the rotational speed of each wheel. They are an explanatory diagram (b) showing the vehicle speed when the accelerator is pressed while the vehicle is traveling straight on a snowy road, and an explanatory diagram (c) showing the rotational speed of each wheel.

[1. Configuration of electronic equipment]
FIGS. 1 and 2 show a radar detector 1 which is a preferred embodiment of the electronic device constituting the system of the present invention. FIG. 1(a) is a perspective view of the front side (the surface facing the rear of the vehicle (driver side)) of the radar detector 1, and FIG. 1(b) is a perspective view of the back side. FIG. 2 is a block diagram of the radar detector 1. As shown in FIG.

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

A display 5 is provided on the front surface of the case body 2 (the surface facing the rear of the vehicle (driver side)). The display 5 is composed of a 3.2-inch color TFT liquid crystal display. A touch panel 6 is provided on the display 5 to detect which part of the display 5 is touched. Further, a volume adjustment button 7 is arranged on the right side of the front surface of the case body 2, and various work buttons 8 are arranged on the left side.

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 inside the card insertion slot 9 inside the case body 2. Ru. By inserting the memory card 11 through the card insertion slot 9, the memory card 11 is attached to the memory card reader 10. The memory card reader 10 takes in data stored in the attached memory card 11. More specifically, the data stored in the memory card 11 includes updated information such as new alarm target information (location information such as longitude and latitude, type information, etc.), and this updated information is used for control purposes. The data is stored (downloaded) in a database 19 built into the device under the control of the unit 18, and the data is updated.

The database 19 can be realized by a nonvolatile memory (eg, EEPROM) inside the microcomputer of the control unit 18 or externally attached to the microcomputer. Note that map data and information regarding certain warning targets are registered in the database 19 at the time of shipment, and data regarding warning targets added thereafter are updated as described above.

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 wireless receiver 15 are placed next to it. The GPS receiver 13 receives GPS signals from GPS satellites and outputs current position (longitude/latitude) information. The microwave receiver 14 receives microwaves of a predetermined frequency emitted from the speed measuring device. The radio receiver 15 receives incoming radio waves of a predetermined frequency. A speaker 16 is also built into the lower part of the case body 2. A speaker port is provided on the bottom surface of the case body 2.

A DC jack 12 is arranged below 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 socket of a vehicle via the cigarette plug cord to receive power supply.

In addition to the display 5 described above, a lamp 31, a remote control receiver 32, and an infrared communication device 34 are arranged on the front surface of the case body 2 (not shown in FIG. 1). The lamp 31 provides a warning by shining in various colors depending on the type and urgency of the warning. The remote control receiver 32 performs data communication with a remote control (portable device: child device) 33 using infrared rays, and performs various settings for the device. The infrared communication device 34 sends and receives data to and from a communication device including a built-in infrared communication device, such as a mobile phone 35.

The case body 2 includes a geomagnetic sensor 36 and an acceleration sensor 37. The geomagnetic sensor 36 is a sensor that detects geomagnetism and detects which direction the north direction is with respect to the direction of travel. The acceleration sensor 37 is a sensor that detects longitudinal, lateral, and vertical acceleration of the vehicle.

Further, the radar detector 1 of this embodiment is connected to an OBD-II (II is the Roman numeral "2", hereinafter "OBD-II" will be referred to as "OBD2") connector installed in a vehicle. A connection cable 22 is provided. A plug 23 is attached to the tip of the connection cable 22, which can be detachably attached to the OBD2 connector of the vehicle. The OBD2 connector is also called a failure diagnosis connector, is connected to the ECU of the vehicle, and outputs various vehicle information.

The other end of the connection cable 22 is provided with a connector terminal 25 for connection to a socket opening 24 provided on the side surface of the case body 2 of the radar detector 1. It is made to be removable. Of course, the connection cable 22 may be directly connected to the radar detector 1.

By connecting the plug 23 attached to the connection cable 22 and the OBD2 connector on the vehicle main body side, the control unit 18 is connected to the in-vehicle network that controls the vehicle, and transmits various vehicle information by 0.5 Get every second. This vehicle information includes, for example, vehicle speed, engine speed, engine load factor, throttle degree, ignition timing, percentage of remaining fuel, intake manifold pressure, intake air amount (MAF), injection opening time, and engine cooling water temperature. (cooling water temperature), temperature of air taken into the engine (intake air temperature), air temperature outside the vehicle (outside air temperature), amount of remaining fuel in the fuel tank (remaining fuel amount), fuel flow rate, instantaneous fuel consumption, accelerator opening, There is turn signal information (left and right turn signal operations (ON/OFF)), brake opening, steering wheel rotation angle information, etc.

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, and is connected to various input devices (touch panel 6, GPS receiver 13, microwave receiver 14). , wireless receiver 15, etc.), and outputs a predetermined alarm/message using output devices (display 5, speaker 16, etc.). These basic configurations can be basically the same as conventional ones. For example, for audio output, audio PCM data is stored on an EEPROM, which is a non-volatile memory, and the control unit 18 reproduces this PCM data and outputs audio from the speaker 16.

[2. Basic functions of electronic devices]
The functions of the radar detector 1 of this embodiment are realized by being stored in the EEPROM of the control unit 18 as a program executed by the computer that is the control unit 18, and executed by the computer included in the control unit 18. Functions realized by the computer by the program included in the control unit 18 include a GPS log function, a standby screen display function, a map display function, a GPS alarm function, a radar wave alarm function, a radio alarm function, and the like.

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

The standby screen display function is a function that displays a predetermined standby screen on the display 5. FIG. 3A shows an example of a standby screen, which shows the speed, latitude, longitude, and altitude of the own vehicle detected by the GPS receiver 13.

The map display function is a function that accesses the database 19 based on the current position detected by the GPS receiver 13, reads out and displays map data stored therein, as shown in FIG. 3(b). In addition, the map display function searches for warning targets around the current location based on the location information stored in the database 19, and if there are warning targets around, displays the warning target at the corresponding position on the map. It also has a function to display information (target icon 112, etc.) in an overlapping manner. The specific display mode is as follows.

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

The control unit 18 displays status information in a status area R2 set above the main display area R1. The status information displayed in status area R2 is, from the left, the current time 121 (in the figure, "15:10"), the GPS radio reception level display icon 122 (in the figure, three straight lines of different lengths are arranged in parallel) maximum reception level), no-parking area icon 123 (displayed when in the most important parking area or within the most important parking area), reception sensitivity mode display icon 124 indicating the radar reception sensitivity (in the figure, "SE", the highest sensitivity) ), vehicle speed 125 ("30 km/h" in the figure), and magnetic compass 126. The status area R2 is a transparent area and is arranged using a layer above that of the main display area R1. As a result, even within the status area R2, the map located below can be visually recognized at locations where status information is not displayed.

The control unit 18 displays current scale information (reduced scale) in a scale display area R3 set on the left side of the main display area R1. The scale assumes that the own vehicle position is 0 m, and displays the distance from the own vehicle position to the vertically intermediate position of main area R1 ("500" in the figure) and the distance to the upper position ("1000" in the figure) do. The unit is "m". When the control unit 18 detects that the main display area R1 has been touched twice consecutively, it displays a map scale change button at a predetermined position in the main display area R1 (a position along the scale display area R3) (as shown in the figure). (omitted), the map scale is changed according to the touch on the map scale change button. That is, the control unit 18 changes the scale of the map displayed in the main display area R1 according to the changed map scale, and also changes the scale information displayed in the scale display area R3.

During execution of the standby screen display function as shown in FIG. 3(a), the control unit 18 detects one touch on the display 5 and displays a menu screen. When the control unit 18 detects that a screen switching button prepared in the menu screen is touched, the control unit 18 switches to a map display function as shown in FIG. 3(b). Similarly, when the control unit 18 detects one touch on the display 5 while executing the map display function, the control unit 18 displays a menu screen. When the control unit 18 detects that a screen switching button prepared on the menu screen is touched, it performs a process of switching to the standby screen display function.

During the execution of the standby screen display function and the map display function (hereinafter these functions are collectively referred to as standby functions), the control unit 18 controls the GPS alarm function, radar wave alarm function, and wireless alarm function according to an event that occurs. It executes processing to realize each function such as an alarm function, and returns to the original standby function processing when the processing of the function is completed. The priority of each function is set in the order of radar wave warning function, radio warning function, and GPS warning function from the highest.

The GPS alarm function is a process that is executed at predetermined time intervals (1 second intervals) based on events from a timer included in the control unit 18. This process calculates the distance between the two from the latitude and longitude of the warning target stored in the database 19 and the latitude and longitude of the current position detected by the GPS receiver 13, and when the calculated distance reaches a predetermined approach distance, the display is displayed. A GPS alarm display 130 (schematic diagram of the alarm target, remaining distance, etc.), which is an alarm screen as shown in FIG. This is the process of outputting.

These warning targets include drowsy driving accident points, speed measurement devices (radar type, loop coil type, H system, LH system, phototube type, mobile type, etc.), speed limit switching points, enforcement areas, inspection areas, parking monitoring. Area, N system, traffic monitoring system, intersection monitoring point, red light prevention system, police station, accident-prone area, vehicle-targeting area, sharp/continuous curves (expressway), branching/merging point (expressway), ETC Advance lane guidance (expressways), service areas (expressways), parking areas (expressways), highway oasis (expressways), smart interchanges (expressways), PA/SA gas stations (expressways), tunnels (expressways) roads), highway radio reception areas (expressways), prefectural border announcements, roadside stations, viewpoint parking, etc., and type information of these objects, latitude and longitude information indicating their positions, and a schematic diagram displayed on the display 5. Alternatively, photo data and audio data are stored in the database 19 in association with each other.

FIG. 4(a) shows a display example of the radar wave warning function. This radar wave warning function is activated when the microwave receiver 14 detects a signal corresponding to a microwave in a frequency band emitted from a speed measuring device (such as a mobile radar (hereinafter simply referred to as "radar")). This is an alarm function that displays a GPS alarm display 131, which is an alarm screen, on the display 5 and outputs an alarm sound from the speaker 16. For example, when microwaves in the microwave frequency band emitted by a radar are detected by the microwave receiver 14, a schematic diagram or photograph of the radar stored in the database 19 is displayed as shown in FIG. 4(b). At the same time, it reads out the voice data stored in the database 19 and says, ``Radar.'' Be careful of speed. ” is output from the speaker 16. The displayed distance may be, for example, a distance estimated from the electric field strength.

The wireless alarm function is a function that issues an alarm when the wireless receiver 15 receives radio waves emitted by an emergency vehicle or the like so as not to interfere with the vehicle's movement. Radio alarm functions include enforcement radio, car location radio, digital radio, special small radio, police radio, police telephone, police activity radio, towing radio, helicopter radio, fire helicopter radio, fire radio, emergency radio, and highway radio. , scans the frequencies of security radios, etc., and when a radio signal is received at the scanned frequency, a schematic diagram indicating that a radio signal corresponding to the frequency has been received stored in the database 19 for each radio type is displayed as an alarm screen. In addition to displaying the information on the display 5, the audio data stored in the database 19 for each wireless type is read out, and the speaker 16 outputs a warning voice indicating the wireless type. For example, if you receive a police radio signal, it will say, ``This is a police radio signal. Be careful of speed. ” is output.

[3. Vehicle driving state detection function]
The vehicle driving state detection function that the control unit 18 realizes in addition to the above-mentioned basic functions will be described. The driving state detection function of the vehicle includes a function of acquiring information regarding wheel rotation, a function of detecting a direction change of the vehicle, a function of detecting an abnormal state of the vehicle, and the like.

[Function to acquire information regarding wheel rotation]
The function of acquiring information regarding the rotation of the wheels is a function of acquiring information regarding the rotation of the wheels from the in-vehicle network that controls the vehicle. The details of this function are as follows.

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 connects to the in-vehicle network that controls the vehicle. Connected.

This in-vehicle network is a CAN (Controller Area Network) to which computers (ECUs) placed in various parts of the vehicle are connected to control the vehicle, and through which data used to control the vehicle itself flows. In this way, it is sufficient to simply 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 them with wires.

The control unit 18 does not make inquiries to the ECU by transmitting remote frames or the like. The control unit 18 acquires information regarding the rotation of each wheel, which is transmitted to the CAN and used to control the vehicle itself, at intervals of 10 ms. This information is information regarding the rotational speed of each wheel, which is used for ABS (anti-lock braking system) and is output from a sensor that detects the rotational status of each of the four wheels. The resolution of information regarding the wheel rotation speed from the sensor used in ABS is 10 to 100 times higher than the vehicle speed (1 km/h step).

In addition, in the case of a vehicle equipped with a steering angle sensor, steering wheel rotation angle information (steering wheel steering angle) can also be obtained from the OBD 2 as described above. 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 change the direction of the vehicle and detect abnormal conditions based on the information output from the sensor used for ABS. It is said that

[Vehicle direction change detection function]
The vehicle direction change detection function allows the control unit 18 to detect a vehicle direction change as information regarding a change in the traveling direction of the vehicle based on the relationship between the information regarding the rotation of two different wheels acquired by the above information acquisition function. This is a detection function. The details of this function are as follows.

First, the database 19 stores information regarding the rotational speed of each wheel, which is transmitted onto the CAN every 10 ms, which is acquired by the control unit 18. Then, the control unit 18 calculates the ratio of the instantaneous values of information regarding the rotational speeds of the two wheels at the same time, and subtracts 1 from the value of this ratio. In this embodiment, the value obtained through such calculation is called a wheel difference ratio.

The two wheels that can be the targets for calculating the wheel difference ratio are as follows.
・Front left wheel and front right wheel ・Rear left wheel and rear right wheel ・Front left wheel and rear left wheel ・Front right wheel and rear right wheel ・Front left wheel and rear right wheel ・Front right wheel and rear left wheel

(Example of measuring wheel difference ratio during actual driving)
An example will be described in which the wheel difference ratio between the front left wheel and the front right wheel is determined as described above while driving on an actual road. The route traveled is a gourd-shaped road connected to a straight road, as shown in Figure 5, and the vehicle enters the gourd-shaped road from the straight road, circles clockwise, and exits the straight road again. is running on.

FIG. 6 is a graph in which the vertical axis represents the wheel difference ratio (%) determined by the control unit 18 as described above while traveling the route shown in FIG. 5, and the horizontal axis represents time (seconds). The total measurement time on the horizontal axis of this graph is 94 seconds. Further, in the graph of FIG. 6, the steering wheel rotation angle information (steering wheel steering angle) obtained by the control unit 18 from the OBD 2 at the same time as the measurement is also shown in deg (°) on the right vertical axis. The graph in FIG. 6 can be displayed on the display 5 during the measurement or after the measurement is completed, based on the data obtained by the control unit 18 and stored in the database 19 as described above.

The measurement results will be specifically explained below with reference to FIGS. 5 and 6. The curves (1) to (9) in the route in FIG. 5 correspond to the curves (1) to (9) in FIG. 6. The arrow in FIG. 5 indicates the direction of travel of the vehicle. First, the vehicle goes straight on the left straight path in FIG. 5 and enters the gourd-shaped path. 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.

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. Furthermore, the vehicle passes through the right-hand curve (3). At this time, the steering angle reaches about -40.0° and the wheel difference ratio reaches about -4.00.

Thereafter, the vehicle passes through the gentle right-hand curve (4). At this time, the steering angle reaches about -20.0° and the wheel difference ratio reaches about -2.00. The vehicle then passes through the right-hand curve (5). At this time, the steering angle reaches about -30.0° and the wheel difference ratio reaches about -3.00.

Next, the vehicle passes through the left-hand curve (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 the right-hand curve (7). At this time, the steering angle reaches about -60.0° and the wheel difference ratio reaches about -6.00. After that, the route is almost straight, so both the steering angle and the wheel difference ratio continue to be around 0.

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

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

Note that the control unit 18 may obtain the wheel difference ratio as follows. The instantaneous value of the information regarding the rotational speed of the left front wheel is taken as one value, and the average value of a plurality of consecutive predetermined values is determined. Further, the instantaneous value of the information regarding the rotational speed of the right front wheel at the same time is taken as one value, and the average value of a plurality of consecutive predetermined values is determined. The ratio of the average value of the left front wheel and the average value of the right front wheel determined in this manner is determined, and 1 is subtracted from this ratio value. After calculating the value using the average value of multiple values, the method of calculating the average value by excluding the oldest value and including the next value is used. Find the wheel difference ratio.

A graph in which the vertical axis is the wheel difference ratio determined in this way and the horizontal axis is time is shown in FIG. This graph also shows the steering wheel angles obtained by the control unit 18 from the OBD 2 at the same time. As is clear from this graph, the wheel difference ratio obtained from a plurality of average values of instantaneous values of information regarding the rotational speed of the wheels also substantially matches the steering angle. Further, by using the average value, even if there is a value that is extremely different from the others among the multiple values, it is equalized to a value that is approximated by the steering wheel angle.

(Example of measuring the rotational speed of each wheel during actual driving)
As mentioned above, in order to show the reason why a direction change can be detected by the wheel difference ratio, when the vehicle simply goes straight through a parking lot, turns around to the right, and returns to going straight again, the control unit 18 Figure 8 shows data obtained by measuring and comparing the rotational speeds of the wheels. The graph in FIG. 8 can also be displayed on the display 5 during the measurement or after the measurement is completed, based on the data acquired by the control unit 18 and stored in the database 19 as described above.

FIG. 8(a) is a graph showing vehicle speed. This vehicle speed may be a value acquired from OBD2 or a value based on GPS. 1/100 of the value on the vertical axis indicates the speed km/h. The numbers on the horizontal axis indicate seconds. The measurement time was 30.9 seconds.

FIG. 8(b) is a graph showing the rotational speed of each wheel measured at the same time as the vehicle speed described above. The vertical axis is the instantaneous value of information regarding the rotational speed of each wheel. The timing of acquisition is approximately every 0.01 seconds. The numbers on the horizontal axis indicate seconds.

As shown in FIG. 8(a), the vehicle speed increases around 2.3 to 4.5 seconds from the start of measurement. At this time, since the vehicle is traveling straight, the rotational speeds of each wheel are approximately the same, as shown in FIG. 8(b). Then, in the vicinity of 4.5 to 23.0 seconds, since the vehicle is traveling clockwise, there is a difference in the rotational speed of each wheel. Furthermore, from around 24.3 seconds, the vehicle speed decreases, the vehicle returns to straight-ahead travel, and the rotational speeds of each wheel match again.

Here, as shown in Fig. 8(b), when the vehicle is running clockwise, the inner right front wheel and right rear wheel are slow in rotation, and the outer left front wheel and left rear wheel are rotating. The speed is increasing. Further, the left front wheel has the fastest rotation speed, and the right rear wheel has the slowest rotation speed.

Therefore, in the case of a simple right turn, the wheel difference ratio between the left front wheel and the right rear wheel, which are diagonally located wheels, is the largest. In the case of a left turn, it is easy to infer that, on the contrary, the wheel difference ratio between the right front wheel and the left rear wheel increases. The next largest wheel difference ratio is between the left front wheel and the right front wheel, or between the left rear wheel and the right rear wheel. The wheel difference ratio between the left front wheel and the left rear wheel or the right front wheel and the right rear wheel is smaller than the others, but the difference is clearly visible. For example, in FIG. 8B, the numerical values indicating the rotational speed 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.

As described above, it is clear that the rotational speed of each wheel differs when the vehicle changes direction. Therefore, the control unit 18 can detect a direction change by comparing information regarding the rotational speed of any two wheels.

[Vehicle abnormal state detection function]
The abnormal state detection function of the vehicle is a function in which the control unit 18 detects a slip of a specific wheel as an abnormal state of the vehicle based on the relationship between information regarding the rotation of at least two different wheels. Note that the graph shown below can also be displayed on the display 5 by the control unit 18 based on data stored in the database 19 during or after measurement.

(snowy road sudden brake)
FIG. 9 is a graph showing a slip state when a sudden brake is applied while driving straight on a snowy road in a front-wheel drive vehicle. In FIG. 9(a), the vertical axis shows vehicle speed, and the horizontal axis shows time. The vehicle speed may be a value obtained from OBD2 or a value based on GPS. 1/100 of the value on the vertical axis indicates the speed (km/h). Furthermore, the numbers on the horizontal axis indicate seconds. The total measurement time on the horizontal axis is 95 seconds. The vertical axis in FIG. 9(b) is the instantaneous value of information regarding the rotational speed of each wheel measured at the same time as the vehicle speed described above. The timing of acquisition is approximately every 0.01 seconds. The numbers on the horizontal axis indicate seconds.

First, as shown in FIG. 9(a), the vehicle continues to run stably until approximately 25 seconds after the start of measurement, and the rotational speeds of each wheel are approximately the same. Then, around 25 seconds, the brakes are strongly pressed. If there were no ABS, the rotation of the wheels would be locked, so the rotational speed of the wheels would be approximately zero. However, since the ABS is working, the rotational speed of each wheel is only slightly reduced. ABS is controlled by appropriate control values for each wheel. However, the resulting actual rotational speed of each wheel will differ. This is due to differences in the steering angle, the condition of the road surface, and the state of contact between each wheel and the like.

For this reason, as shown in FIG. 9(b), the left front wheel has the lowest rotational speed and is slipping significantly. Here, if the control unit 18 determines that the slip is a slip based on a threshold value set in advance in the database 19, the control unit 18 displays a message such as "Left front wheel slips" superimposed on the graph as shown in FIG. 9(b). 5 to give a warning. The warning display area should be an area that avoids the lines indicating data.

The threshold value may be, for example, a case where the rotational speed of a specific wheel has decreased by one-third or more of the rotational speed of any other wheel. Note that the threshold value for the warning may be determined based on experiments, etc., and it is not necessary to issue a warning in all cases where a difference occurs in the rotational speed of the wheels.

After this, the brakes continued to be applied from around 25 to 47 seconds. Therefore, as shown in FIG. 9(a), the vehicle gradually decelerates. In particular, around 33 seconds, as shown in FIG. 9(b), the rotational speed of the right front wheel is the lowest and it is slipping significantly. Here, the control unit 18 causes the display 5 to display a speech bubble saying "Right front wheel slips" superimposed on the graph to issue a warning.

Then, around 47 to 56 seconds, the brakes were not applied. Therefore, as shown in FIG. 9(a), the vehicle speed is decreasing very slowly. At this time, as shown in FIG. 9(b), the rotational speeds of the respective wheels are stable and substantially the same. Furthermore, at around 56 seconds, the brakes were pressed again. As a result, the vehicle speed suddenly decreases as shown in FIG. 9(a).

At this time, as shown in FIG. 9(b), the right front wheel slows down the most and slips significantly. Here, the control unit 18 causes the display 5 to display a speech bubble saying "Right front wheel slips" superimposed on the graph to issue a warning. Next, the left front wheel also slowed down and began to slip. Here, the control unit 18 causes the display 5 to display a speech bubble saying "Left front wheel slips" superimposed on the graph to issue a warning.

From around 63 seconds onwards, the rotational speeds of each wheel are stable and almost the same. After that, the vehicle continued to run stably, and from around 70 seconds onwards, the speed gradually increased by stepping on the accelerator without applying the brakes.

(Snowy road accelerator 1)
FIG. 10 is a graph showing a slip state when the accelerator is pressed while driving straight on a snowy road in a front-wheel drive vehicle. In FIG. 10(a), the vertical axis from 0 to 6000 rpm indicates the engine rotation speed, and the horizontal axis indicates time (seconds). In FIG. 10(b), the vertical axis 0 to 8000 indicates vehicle speed (1/100 is speed km/h), and the horizontal axis indicates time (seconds). In FIG. 10(c), the vertical axis represents the rotational speed of each wheel, the horizontal axis represents time (seconds), and the total measurement time is 155 seconds.

As shown in FIG. 10(a), when the accelerator is depressed around 3.7 seconds from the start of measurement, the engine speed rapidly increases. At around 11.2 seconds, the driver is still pressing the accelerator, but the rate of increase in engine speed slows down slightly because the vehicle is climbing the slope. As shown in FIG. 10(b), the vehicle speed increases at around 12 seconds, delayed by the increase in engine speed around 3.7 seconds. Note that when the vehicle speed decreases, the engine speed also decreases.

Here, around 12 seconds when the vehicle speed increases, the rotational speed of the left front wheel increases and slips, as shown in Fig. 10(c), and after about 4 seconds, the rotational speed of the right front wheel increases and slips. do. When the control unit 18 determines that there is a slip based on the threshold value set in advance in the database 19, the control unit 18 displays the message balloons “Left front wheel slips” and “Right front wheel slips” in a graph, as shown in FIG. 10(c). is displayed on the display 5 to give a warning.

The threshold value may be a case where the rotational speed of a specific wheel becomes one-half or more of the rotational speed of any other wheel. The threshold value when applying the brakes is the same as the above-mentioned sudden braking on snowy roads. The threshold value for a warning may be determined based on experiments, etc., and it is not necessary to issue a warning in all cases where a difference occurs in the rotational speed of the wheels.

After that, around 23 to 76 seconds, as shown in FIG. 10(a), the engine speed fluctuates, but this is simply due to the accelerator being depressed depending on the terrain. Therefore, as shown in FIG. 10(b), the vehicle speed increases gradually until around 82 seconds. Moreover, as shown in FIG. 10(c), the rotational speeds of each wheel are the same.

Furthermore, as shown in FIG. 10(a), after the accelerator is suddenly depressed at around 76 seconds, the accelerator is continued to be lightly depressed until around 110 seconds. Then, as shown in FIG. 10(b), the vehicle speed suddenly increases around 82 seconds, then decreases once, and then increases again. At this time, as shown in Fig. 10(c), the speeds of the right front wheel and left front wheel suddenly increase and both slip, and while the right front wheel returns to its original position, the left front wheel continues to slip, and the right front wheel continues to slip. The front wheels started to slip, and around 117 seconds, both returned to normal.

At this time, as shown in FIG. 10(c), the control unit 18 displays speech bubbles such as "Front left wheel slips" and "Front right wheel slips" on the display 5 superimposed on the graph to warn of the slip. . The reason why only the front wheels slip left and right in this way is because they are the driving wheels. Furthermore, the reason why the left and right wheels behave differently is because they have different slipperiness, such as when the right wheel is on the road and the left wheel is on ice.

Next, as shown in FIG. 10(a), when the accelerator is depressed around 126 seconds, the engine speed suddenly increases. After this, at around 131 seconds, the vehicle speed increases slightly, as shown in FIG. 10(b), and the left front wheel slightly slips, as shown in FIG. 10(c). However, the control unit 18 does not issue a warning because this degree of increase in rotational speed is a slight slip that does not reach the threshold.

Finally, as shown in Fig. 10(a), when the brake is stepped on at around 151 seconds, the vehicle speed decreases slightly as shown in Fig. 10(b), and as shown in Fig. 10(c), The front left wheel slips slightly. In this way, the slip caused by the brake appears as a decrease in rotational speed, contrary to the slip caused by the accelerator. Note that the control unit 18 does not issue a warning because this degree of slip is a mild slip that does not reach the threshold value.

(Snowy road accelerator 2)
Similar to FIG. 10, FIG. 11 is a graph showing a slip state when the accelerator is pressed while driving straight on a snowy road in a front-wheel drive vehicle. However, the measurement time on the horizontal axis is longer at 321 seconds than in FIG. In FIG. 10(a), the vertical axis 0 to 7000 indicates vehicle speed (1/100 is speed km/h), and the horizontal axis indicates time (seconds). In FIG. 10(b), the vertical axis represents the rotational speed of each wheel, and the horizontal axis represents time (seconds).

As is clear from this graph, when you press the accelerator on a snowy road and the vehicle speed increases rapidly, the rotational speed of the right front wheel and left front wheel increases, causing a slip, similar to snowy road slip 1. Recognize.

[4. Effects of embodiment]
According to this embodiment as 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, there is no need to install sensors on a plurality of different wheels and connect them with wires. This is particularly effective when it is not possible to obtain the steering wheel angle, etc. from the network that controls the vehicle, or when the data format, etc. is not made public and is difficult to obtain.

(B) In the configuration in which information regarding changes in the traveling direction of the vehicle is obtained using GPS, information regarding changes in the traveling direction of the vehicle cannot be obtained in places where GPS radio waves are blocked and positioning is not possible. By obtaining information regarding the rotations of at least two different wheels, information regarding changes in the direction of travel of the vehicle can be determined. Note that the control unit 18 may be configured to correct the travel distance determined by GPS based on information regarding changes in the traveling direction of the vehicle.

In the case of a vehicle that does not have a steering angle sensor, even if there is a steering angle sensor, its use is limited, or even if the steering angle sensor is malfunctioning, the control unit 18 can control the operation of at least two different wheels. By obtaining signals related to rotation, information regarding changes in the direction of travel of the vehicle can be obtained.

(C) The resolution of information regarding wheel rotation in the network through which data used to control the vehicle itself flows is 10 to 100 times higher than the vehicle speed (1 km/h step). Therefore, the quantum error becomes small, and even when the vehicle is running at low speed, the error in the information regarding the change in the traveling direction of the vehicle obtained by the control unit 18 from the information regarding the rotation of the wheels becomes extremely small. Therefore, the control unit 18 can accurately obtain information regarding changes in the traveling direction at a level comparable to that of the steering angle sensor.

The control unit 18 calculates vehicle speed, mileage, and separately acquired engine information from information regarding wheel rotation in a network through which data used to control the vehicle itself flows, along with information regarding changes in the traveling direction of the vehicle. It is also possible to calculate the gear ratio from the rotation speed and vehicle speed. Errors in the vehicle speed, travel distance, gear ratio, etc. determined in this way can also be reduced.

(D) The network provided in the vehicle is a wired network. Therefore, the control unit 18 can obtain information regarding a change in the traveling direction of the vehicle by simply connecting a wire to one location of the signal line (for example, a group of signal lines) of the network. In particular, since it is configured to be connected to a connector that can be attached to and detached from the network signal line, it can be easily connected.

(E) By using information corresponding to only two wheels, the control unit 18 reduces the amount of information to be processed, making it possible to simplify and speed up the processing. Further, the control unit 18 acquires and uses instantaneous values of information regarding the rotation of at least two wheels at approximately the same time from the network every 10 ms. Therefore, this information is sufficient for the control unit 18 to obtain information regarding a change in the traveling direction of the vehicle.

(F) Since the control unit 18 reads information flowing through the network without collecting information by asking the devices connected to the network, stress on the devices connected to the network can be avoided. In particular, the computer that outputs information about the rotation of the wheels to the network does not have to respond to questions, so stress can be avoided. Furthermore, since network traffic does not increase, stress on the overall control of the vehicle can be avoided.

(G) The control unit 18 displays on the display screen of the display device 5 the information regarding the steering wheel angle obtained from the network and the information regarding the steering wheel angle obtained based on the relationship between the information regarding the rotation of two different wheels. let For this reason, vehicle occupants including the driver who viewed the display screen can obtain information based on the relationship between information regarding the steering wheel angle obtained from the network that controls the vehicle and information regarding the rotation of two different wheels. This information can be compared with information regarding the steering wheel angle. The passenger of the vehicle who has compared both pieces of information regarding the steering wheel angle in this manner can determine whether the vehicle is changing direction or is in an abnormal state based on the degree of difference between the pieces of information.

Further, since the abnormal state of the vehicle is displayed on the display screen of the display device 5, the passengers of the vehicle 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 occupants of the vehicle aware of the slip by displaying a warning to notify the occurrence of the slip over the graph using a speech bubble. 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 line indicating the data. Further, by not warning the driver of a slight slip, the control unit 18 can prevent the warning from being displayed frequently and making it difficult to recognize the danger.

Furthermore, the occupants of the vehicle, including the driver, who view the display screen can recognize the change in the direction of travel of the vehicle and determine the driving state of the vehicle based on this change in the direction of travel of the vehicle. It can be useful for safe driving and eco-driving.

(H) Since the control unit 18 uses signals from sensors used in ABS (anti-lock brake system), it is possible to save the effort and cost of adding a special sensor. Furthermore, information based on signals from the sensor used in the ABS has higher resolution than the vehicle speed sensor in the transmission, so the direction can be detected accurately.

Furthermore, even if the information regarding the wheel rotation that the control unit 18 acquires from the network includes a value that is extremely different from the others among multiple values, rather than using that value as is, By using the average value of the values, it is possible to equalize the value to a value that more closely approximates the steering angle. Therefore, the direction can be detected closer and more accurately by the steering angle sensor.

[5. Other embodiments]
The present invention is not limited to the embodiments described above.
(a) "Information regarding the rotation of the wheel" 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. Such information also indicates different values for each wheel when the vehicle changes direction or an abnormal running state occurs, so similarly to the above embodiment, the control unit 18 detects the direction change or abnormal state. becomes possible.

(b) The "network that controls 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 use information about the steering wheel angle acquired from a network that controls the vehicle. can be compared with information regarding the steering wheel angle determined based on the relationship between information regarding 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 a network.

A person outside the vehicle who has compared both pieces of information regarding the steering wheel angle in this way can recognize a direction change or an abnormal state of the vehicle based on the degree of difference between the two pieces of information. Furthermore, if the abnormal state of the vehicle is displayed 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/herself. Furthermore, a person outside the vehicle who looks at the display screen can recognize changes in the vehicle's direction of travel and determine the driving state of the vehicle based on this change in the vehicle's direction of travel, thereby improving safe driving. It can be useful for eco-driving.

For example, in a taxi company or a transportation company, a display screen installed in the company can be used to check changes in the direction of travel of a driver's vehicle in the past or present, and determine the driving condition of the driver. It is good to use this as an indicator to encourage safe and eco-driving. Also, for example, a driver can check past changes in the direction of travel of his or her vehicle on a display screen at home, determine the driving condition, and improve his/her own safe and eco-friendly driving. It is a good idea to use this as an indicator to aim for. In this case, as mentioned above, a computer outside the vehicle may acquire information via the network and display it on the display screen, or the information may be recorded on the memory card 11 inserted into the system installed inside the vehicle. Information may be displayed on a display screen by reading the memory card 11 with a computer outside the vehicle.

(c) There may be two or more "at least two different wheels" that are subject to information regarding rotation. For example, of the information corresponding to the two wheels and the information corresponding to the other two wheels, the one showing a normal value may be used, or the average of both pieces of information may be used. In this way, highly accurate detection becomes possible. As described above, the information regarding the wheels may have a value that is extremely different from the others out of multiple values, but the control unit 18 may obtain a normal value or an average value and use it for detection. This allows such values to be eliminated or leveled out.

(d) "Information regarding a change in the traveling direction of the vehicle" may be, for example, information indicating the degree of difference in information regarding the rotation of at least two wheels. For example, the information may be based on the difference between values indicated by information regarding the rotation of two wheels. Further, for example, the information may be based on a ratio of values indicated by information regarding the rotation of two wheels. Since such information also provides values that differ depending on the direction of travel, the control unit 18 can detect changes in the direction of travel.

The control unit 18 may detect a change in the traveling direction, for example, by detecting only a right or left turn at a fork. In this way, the number of directions to be determined by the control unit 18 is reduced, making it possible to simplify and speed up the processing. Further, the change in the traveling direction may be a change in the traveling angle or a change in the steering angle of the steering wheel. This system can detect even detailed changes in the direction of travel because it can detect with the same accuracy as the steering wheel angle. In this way, the control unit 18 can determine the driving state in more detail. For example, the control unit 18 can detect a change in the direction of travel in the same lane or a change in the direction of travel when changing lanes. Furthermore, even if GPS positioning is not possible, the control unit 18 can detect changes in the direction of travel in road curves at overpasses, underground, tunnels, and the like.

(e) The information regarding the steering wheel angle obtained from the network accurately indicates the steering angle, but the information regarding the steering wheel angle obtained based on the relationship of information regarding the rotation of at least two different wheels is Depending on the situation, there may be a difference from the actual steering angle. Therefore, the control unit 18 can also detect an abnormal state of the vehicle based on a relationship in which the two pieces of information are significantly different, such as a difference greater than a threshold value set in advance in the database 19.

As a method for determining the steering wheel angle based on the relationship of information regarding the rotation of the wheels, the following may be used. First, the control unit 18 collects information regarding the steering angle of the steering wheel at approximately the same time and the rotation of at least two different wheels at a time interval necessary to generate information regarding the change in the traveling direction of the vehicle according to the application. A log obtained by the above is created and stored in the database 19. The control unit 18 calculates a function of the correspondence between 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, and uses the function to calculate the information on the rotation of the wheels. Find the steering angle based on the relationship. For example, the control unit 18 associates the difference or ratio of the instantaneous values of the rotation speeds of two different wheels at the same time with the steering wheel angle at the time and stores it in the database 19 as a log. Alternatively, the correlation between the ratio and the steering angle is stored in the database 19 as a function. The function may be incorporated into the program as a mathematical formula, or a table or the like for determining a mapping may be created and stored, and the function may be configured as a program that performs calculations using this table. Such a program created based on past information may be stored in advance in the database 19, and the control unit 18 may be configured to operate based on this program.

The data format of information regarding wheel rotation and steering wheel angle flowing through the network may differ depending on the vehicle model. The correspondence between the information regarding the rotation of the wheels and the steering angle is determined in advance for each vehicle type, and a function is determined and stored in the database 19 as a program or data. The system is provided with a function in which the control unit 18 automatically detects the vehicle type or allows the user to manually configure the vehicle type. The control unit 18 determines the correspondence between the set vehicle type, information regarding the rotation of the wheels, and the steering angle of the steering wheel. The control unit 18 can detect an abnormal state of the vehicle, such as a tire blowout or slip, based on the relationship between the steering wheel angle obtained in this way and the steering wheel angle obtained from the network. This allows accurate detection even if the vehicle type is different.

(f) By setting the abnormal state of the vehicle as a state in which the rotational speed of a specific wheel is significantly different from that of other wheels, the control unit 18 can detect the slippage of a specific wheel on a snowy road, ice burn, or muddy road. It can also detect traction abnormalities, punctures, and air pressure abnormalities.

(g) The manner in which the control unit 18 displays information regarding the rotation of the wheels on the display 5 is, for example, information regarding the steering wheel angle acquired from a network that controls the vehicle and information regarding the rotation of at least two different wheels. Any form is acceptable as long as it can identify the difference from the information regarding the steering wheel angle determined based on the relationship of the information. It is preferable to display the existence of a difference between the two pieces of information, the magnitude of the difference, and the type of abnormality estimated from the difference. In this way, it is possible to easily determine whether the vehicle is changing direction or in an abnormal state.

The information regarding the change in the traveling direction of the vehicle may be displayed in a manner that allows the driving state of the vehicle to be determined based on the presence or absence of a change in the traveling direction, for example. For example, a mode may be adopted in which instantaneous changes in the traveling direction of the vehicle can be visually grasped. This may be a symbol display such as an arrow on a display screen, or light emission from lamps such as LEDs placed on the left and right sides.

In addition to the above-mentioned speech bubbles, the abnormal state may be displayed in a manner that allows recognition of a puncture, abnormal air pressure, slippage of a particular tire, etc., using letters, graphics, colors, or changes in these. It may be displayed on a display screen or may be emitted by a lamp such as an LED.

Furthermore, it is preferable that the display mode is such that changes in the traveling direction of the vehicle over a predetermined period of time can be visually grasped at once. The predetermined period may be set to a period that allows it to be determined, for example, that the vehicle is repeatedly changing lanes in a short period of time, or that the direction of travel is frequently changing within the same lane.

The driving state of the vehicle determined by a passenger of the vehicle 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 is possible to realize safe driving and eco-driving for vehicle drivers. For example, repeatedly changing lanes in a short period of time may be determined by the vehicle occupant or a person outside the vehicle as a driving state in which passing is frequently performed. For example, frequent changes in the direction of travel within the same lane may be determined by a vehicle occupant or a person outside the vehicle as a driving state such as drunk driving or drowsy driving.

Examples of display modes that allow the driving state to be determined include graphs showing changes in the direction of travel or steering wheel angle over a predetermined period of time, numbers indicating the frequency of changes in the direction of travel or steering wheel angle over a predetermined period, etc. It is good to do this.

(h) The control unit 18 determines the driving state of the vehicle based on the information regarding the change in the traveling direction of the vehicle as described above, and performs control to display the driving state on the display screen of the display device 5. You can. In this way, the vehicle occupants, including the driver, or those outside the vehicle who view the display screen can easily recognize the vehicle driving condition without having to bother themselves to determine the driving condition. The display of the driving state may be, for example, a display that can recognize danger, safety, drowsiness, alcohol consumption, etc. using letters, figures, colors, or changes thereof.

(i) The control unit 18 acquires information regarding the driving operation of the vehicle via the network, and displays the acquired information regarding the driving operation of the vehicle on the display screen of the display device 5 together with information regarding the change in the traveling direction of the vehicle. Display control may also be performed. In this way, information related to vehicle driving operations is displayed together with information related to changes in the direction of travel of the vehicle, so that vehicle occupants including the driver who viewed the display screen, or persons outside the vehicle, can easily understand the direction of travel. The driving state of the vehicle can be determined in more detail based on the relationship between the change in the information on the driving operation and the information on the driving operation.

The information regarding the driving operation of the vehicle may be, for example, information indicating that the driver has operated a member or mechanism that is required to be operated while driving, and the timing thereof. For example, information regarding the driving operation of the vehicle may be information such as when the turn signal was activated, when and how many times the brake was pressed, and when and how many times the accelerator was pressed. For example, if the turn signal is not activated before making a right or left turn, it may be determined that the driving condition is dangerous. For example, if the brake is not pressed or the accelerator is pressed before making a right or left turn, it may be determined that the driving condition is dangerous.

(j) The control unit 18 acquires information regarding the driving operation of the vehicle, and determines 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. However, control may be performed to display the operating state on the display screen of the display device 5. In this way, the occupants of the vehicle, including the driver, who view the display screen, or those outside the vehicle, can easily obtain detailed driving conditions without the trouble of determining the driving conditions themselves.

(k) The control unit 18 may control the speaker 16 to output sound depending on the abnormal state and the operating state. In this way, by outputting the sound, the abnormal state of the vehicle can be reliably notified even to the occupants of the vehicle who are not looking at the display screen or to those outside the vehicle. For example, it is possible to make a passenger of the vehicle or a person outside the vehicle aware of a puncture, abnormal air pressure, slippage of a particular tire, etc. In addition, by outputting the sound, the driving status of the vehicle can be reliably informed to the vehicle occupants or outsiders who are not looking at the display screen. For example, it is possible to warn a vehicle occupant or a person outside the vehicle of the dangers associated with drowsy driving or drunk driving.

(l) When determining the magnitude of thresholds for detecting left/right turns and abnormal conditions, and determining whether they match or do not match, etc., consider values as greater than or less than, greater than, less than, exceed, or do not exceed. You are free to decide not to include values as , greater than, less than, or less than. Therefore, for example, depending on the value setting, "greater than" can become "greater than," "exceeds," or "greater than," and "less than" can become "less than," "not exceeding," "below," or "less than." No matter how you read it, it is essentially the same.

(m) The control unit 18 may be set not to detect the traveling direction of the vehicle when the ABS function is working. When the ABS is working, it is not possible to accurately detect the direction of travel using signals from the sensor, so the control unit 18 does not perform detection in such a case, thereby preventing erroneous judgments and erroneous operations due to erroneous detection.

(n) The control means may be realized by one control section 18 or may be realized by a plurality of control sections 18. All of the control section 18 may be provided inside the vehicle, all of the control section 18 may be provided outside the vehicle, or some of the control section 18 may be provided inside the vehicle and some of it may be provided outside the vehicle. Other parts may also be provided. A system may also be used in which at least a part of the functions of the control unit 18 is placed in a server, the functions are executed by the server, and the electronic device held by the user acquires the execution results. Further, part or all of the information to be registered in the database can be registered in the server. The radar detector and other electronic equipment/devices may have a function of communicating with such a server, and the control unit may access the server as appropriate, acquire necessary information, and execute processing.

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

(p) The system to which the present invention is applied is not limited to the radar detector 1. It is possible to apply the present invention to in-vehicle electronic devices of various configurations, such as car navigation systems and drive recorders. The functions of the present invention can be easily added to an existing system configured as an electronic device by installing a program. Therefore, vehicle owners can take advantage of new functions while reducing expenses.

(q) The system function of the present invention is configured as a program to be realized by a computer included in the control unit 18, but the program is not limited to this, and the program can be distributed to multiple computers and processed in a distributed manner. Good too.

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

Claims (5)

A function to obtain information regarding the rotation of the vehicle's wheels;
a function of detecting an abnormality in the vehicle based on information regarding rotation of the vehicle;
a function of displaying an image showing temporal changes in information according to the rotation of the vehicle;
a function of displaying information regarding the abnormality at a position on the image corresponding to the time when the abnormality occurred;
A system equipped with The system according to claim 1, wherein the image is a graph showing temporal changes in the rotational speed of the vehicle. The acquiring function acquires information regarding rotations of at least two different wheels;
The system according to claim 1 or 2, wherein the function of detecting an abnormality detects an abnormality of the vehicle based on information regarding rotations of the at least two different wheels. The system according to claim 3, wherein the abnormality detecting function detects slippage of a wheel of the vehicle based on a difference in rotational speed of the at least two different wheels. A program for causing a computer to implement the functions of the system according to any one of claims 1 to 4.

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