JP7341875B2 - Tire force display system and tire force display method - Google Patents

Description

The present invention relates to a tire force display system and a tire force display method.

2. Description of the Related Art In order to let passengers and the like know the running state of a vehicle, a system is installed in a vehicle to display the running speed of the vehicle, the state of various devices such as engine temperature, and the like. Indicators that display the vehicle's running speed and the like are mainly placed on the dashboard in front of the driver, making it easy for the driver to visually check the displayed information while driving.

Patent Document 1 describes a conventional system for displaying vehicle information on a wireless mobile device. The wireless mobile device captures vehicle performance data, including engine performance, driving maneuvers, driving speed, location, and weather information, and displays it on a display screen.

Special table 2016-519468 publication

In the system described in Patent Document 1, vehicle performance data is displayed on a wireless mobile device that is located away from the vehicle. By displaying information regarding the tire force generated by the tires installed on a vehicle, the inventors have discovered that by displaying information regarding the tire force generated by the tires installed on a vehicle, it is possible to increase the ability to recognize the behavior of the tires. I noticed that it became easier to recognize.

The present invention has been made in view of the above circumstances, and its purpose is to provide a tire force display system and a tire force display that can display information regarding tire force to improve recognition of tire behavior. The purpose is to provide a method.

One aspect of the present invention is a tire force display system. The tire force display system includes a sensor information acquisition unit that acquires physical quantities of the tire measured by sensors installed on the tire, and inputs the physical quantities of the tire acquired by the sensor information acquisition unit into a calculation model to display tire force and The vehicle includes a tire force calculation section that calculates a limit tire force, and a display section that displays the tire force and the limit tire force calculated by the tire force calculation section.

Another aspect of the invention is a tire force display method. The tire force display method includes a sensor information acquisition step of acquiring a physical quantity of the tire measured by a sensor installed on the tire, and inputting the physical quantity of the tire acquired in the sensor information acquisition step into a calculation model to calculate tire force and The tire force calculation step includes a tire force calculation step of calculating a limit tire force, and a display step of displaying the tire force and the limit tire force calculated in the tire force calculation step.

According to the present invention, information regarding tire force can be displayed to improve recognition of tire behavior.

FIG. 1 is a block diagram showing a functional configuration of a tire force display system according to an embodiment. FIG. 3 is a schematic diagram for explaining learning of a calculation model. FIG. 2 is a schematic diagram for explaining tire force F and limit tire force. FIG. 2 is a block diagram showing the functional configuration of a server device and a terminal device. FIG. 3 is a schematic diagram showing an example of a display image. 7 is a flowchart showing a procedure for display processing of a display image.

Hereinafter, the present invention will be explained based on a preferred embodiment with reference to FIGS. 1 to 6. Identical or equivalent components and members shown in each drawing are designated by the same reference numerals, and redundant explanations will be omitted as appropriate. Further, the dimensions of members in each drawing are shown enlarged or reduced as appropriate to facilitate understanding. Further, in each drawing, some members that are not important for explaining the embodiments are omitted.

(Embodiment)
FIG. 1 is a block diagram showing the functional configuration of a tire force display system 100 according to an embodiment. The tire force display system 100 measures tire physical quantities such as acceleration, air pressure, and temperature generated in the tire 10 by a sensor 20 disposed on the tire 10 while the vehicle is running.

The tire force display system 100 inputs the acquired physical quantities of the tire 10 into the calculation model 32a, and calculates the tire force F and the limit tire force. The limit tire force is the tire force just before the tire 10 starts to slide on the road surface, and is the value obtained by multiplying the vertical load of the tire 10 by the maximum coefficient of friction with the road surface.

The calculation model 32a is, for example, a learning model such as a neural network. The accuracy of the calculation model 32a is improved by using the tire force F and the limit tire force actually measured in the tire 10 as training data, and repeating learning by performing calculations and updating the calculation model.

The tire force display system 100 also estimates the wear state of the tire 10. Tire force display system 100 sends tire information including tire force F, limit tire force, and wear condition to server device 7. The server device 7 generates an image graphically representing the tire force F, the limit tire force, and the wear state, and distributes it to the terminal device 8 , and the terminal device 8 displays the image. Further, the server device 7 stores the tire information and sends it to the terminal device 8, and the terminal device 8 generates an image graphically representing the tire force F, the limit tire force, and the wear condition, and displays the image. It's okay.

The tire force display system 100 improves the visibility of the behavior of the tire 10 by displaying the tire force F, the limit tire force, and the wear state as images.

The tire force display system 100 includes a sensor 20 and a tire force estimation device 30. The sensor 20 includes an acceleration sensor 21, a pressure sensor 22, a temperature sensor 23, etc., and measures physical quantities in the tire 10, such as acceleration, tire air pressure, and tire temperature. The sensor 20 may include a strain gauge to measure strain occurring in the tire 10. These sensors measure physical quantities related to deformation and movement of the tire 10 as physical quantities of the tire 10.

The acceleration sensor 21 is disposed on the tire body portion of the tire 10 made of a rubber material or the like or on the wheel 15 forming a part of the tire 10, and measures the acceleration generated in the tire 10 while mechanically moving together with the tire 10. Measure. The acceleration sensor 21 measures the acceleration of the tire 10 in three axes: the circumferential direction, the axial direction, and the radial direction. The pressure sensor 22 and the temperature sensor 23 are installed, for example, by being attached to an air valve of the tire 10 or fixed to the wheel 15, and measure the air pressure and temperature of the tire 10, respectively. Moreover, the pressure sensor 22 and the temperature sensor 23 may be arranged on the inner liner of the tire 10 or the like.

The sensor 20 measures physical quantities of the tire 10 such as acceleration and strain in the tire 10, tire air pressure, and tire temperature, and outputs the measured data to the tire force estimation device 30. Tire force estimating device 30 estimates tire force F and limit tire force based on data measured by sensor 20.

The tires 10 may be attached with, for example, an RFID 11 assigned with unique identification information in order to identify each tire. For example, depending on the unique information of the RFID 11 attached to the tire 10, the calculation model 32a may be selected and set from a data group prepared in advance, or may be selected from a database provided by a server device, etc. You can also do this. Further, the specifications of the tire 10 may be recorded with respect to the unique information of the RFID 11, and furthermore, the calculation model 32a according to the specifications of the tire 10 may be provided in the database. The specification of the tire 10 may be called from the unique information of the RFID 11 and the calculation model 32a may be set, or the calculation model 32a according to the specification of the tire 10 that has been called may be selected from the database.

The tire force estimation device 30 includes a sensor information acquisition section 31 , a tire force calculation section 32 , a wear estimation section 33 , a storage section 34 , and a communication section 35 . The tire force estimating device 30 is, for example, an information processing device such as a PC (personal computer). Each part of the tire force estimating device 30 can be realized in terms of hardware by electronic elements such as a CPU of a computer, mechanical parts, etc., and can be realized by computer programs in terms of software. It depicts functional blocks realized through collaboration. Therefore, those skilled in the art will understand that these functional blocks can be realized in various forms by combining hardware and software.

The sensor information acquisition unit 31 acquires tire physical quantities such as acceleration, tire air pressure, and tire temperature measured by the sensor 20 through wireless communication or the like. The tire force calculation section 32 includes a calculation model 32a and a correction processing section 32b. The tire force calculation unit 32 inputs the tire physical quantity input from the sensor information acquisition unit 31 into the calculation model 32a, and calculates the tire force F and the limit tire force. As shown in FIG. 1, the tire force F has three axial components: a longitudinal force Fx in the longitudinal direction of the tire 10, a lateral force Fy in the lateral direction, and a load Fz in the vertical direction.

The calculation model 32a uses a learning model such as a neural network. The calculation model 32a is, for example, a CNN (Convolutional Neural Network) type, and uses a learning model including convolution calculations and pooling calculations used in its prototype, so-called LeNet. The calculation model 32a extracts feature quantities using convolution operations, pooling operations, etc. on data input to the input layer, transmits them to each node in the intermediate layer, and performs linear operations, etc. on each node in the intermediate layer. Execute to fully connect and connect to each node of the output layer. In the full connection, in addition to linear operations, non-linear operations may be performed using an activation function or the like. The tire force F in the three axial directions and the limit tire force are output to each node of the output layer of the calculation model 32a.

FIG. 2 is a schematic diagram for explaining learning of the calculation model 32a. As input data to the calculation model 32a, in addition to the tire physical quantity acquired by the sensor information acquisition unit 31, external area information and the like can be used. The tire physical quantities include acceleration, tire air pressure, tire temperature, and strain occurring in the tire. As the external area information, meteorological information such as weather, temperature, and precipitation, and road surface information such as road surface unevenness, temperature, and frozen state are used. In addition to these input data, vehicle weight, speed, etc. obtained from data from a digital tachograph mounted on the vehicle may be used.

When learning the calculation model 32a, the accuracy of the calculation model 32a is improved by comparing the tire force F and the limit tire force as calculation results with teacher data and repeatedly updating the calculation model 32a. The calculation model 32a basically has a configuration and weighting that changes depending on the specifications of the tire 10, such as the number of layers in all the connections in the model, but in a rotation test with the tire 10 (including the wheel) of each specification. Learning of the calculation model 32a can be executed.

However, it is not necessary to perform learning of the calculation model 32a strictly for each specification of the tire 10. For example, by learning and constructing the calculation model 32a for each type of passenger car tire, truck tire, etc., and estimating the tire force F and the limit tire force within a certain error range, it is possible to include tires in multiple specifications. The number of calculation models may be reduced by sharing one calculation model 32a for each tire 10. Further, the calculation model 32a can also be trained by mounting the tires 10 on an actual vehicle and driving the vehicle for a test run. The specifications of the tire 10 include information regarding tire performance, such as tire size, tire width, aspect ratio, tire strength, tire outer diameter, load index, and manufacturing date.

FIG. 3 is a schematic diagram for explaining tire force F and limit tire force. In FIG. 3, the horizontal axis represents the longitudinal force Fx of the tire force F, the vertical axis represents the lateral force Fy of the tire force F, and the limit tire force is shown by a circle centered on the origin. The tire forces F1 and F2 shown in FIG. 3 are smaller than the limit tire force and the vehicle can run without the tires 10 slipping. When the tire force F becomes larger than the limit tire force, the tire 10 enters a state where it slips on the road surface.

The correction processing unit 32b corrects the calculation model 32a based on the condition of the tire 10. When tires 10 are mounted on a vehicle, alignment errors occur, physical properties such as rubber hardness change over time, and wear progresses as the tires are driven. The condition of the tire 10, including elements such as alignment errors, physical property values, and wear, changes depending on usage conditions, and errors occur in the calculation of the tire force F and the limit tire force by the calculation model 32a. The correction processing unit 32b performs a process of adding a correction term according to the condition of the tire 10 to the calculation model 32a in order to reduce errors in the calculation model 32a.

The wear estimation unit 33 estimates the wear state of the tire 10. The wear state of the tire 10 is the amount of wear of the tire 10 or the amount remaining up to the wear limit (for example, remaining groove depth, remaining tread thickness, etc.). The wear state of the tire 10 is estimated by measuring the groove depth provided in the tread of the tire 10 and the radius of the tire 10 using, for example, an optical dimension measuring device (not shown). For dimension measurement using an optical method, a known technique such as a method of measuring the dimensions of an object by image recognition based on an image of the tire 10 or a dimension measurement method using a laser beam can be used.

In addition, the wear estimation unit 33 constructs a calculation model (not shown) that calculates the amount of wear of the tire 10, similarly to the calculation model 32a that calculates the tire force F and the limit tire force, and estimates the amount of wear. Good too. Similar to the calculation model 32a, this calculation model can improve the accuracy of estimating the amount of wear by repeating learning regarding the amount of wear that is the output using the tire physical quantity measured by the sensor 20 as input.

The storage unit 34 is composed of a storage device such as a hard disk, and stores the tire force F and the limit tire force calculated by the tire force calculation unit 32, as well as the wear state of the tire 10 estimated by the wear estimation unit 33. . The communication unit 35 sends tire information including the tire force F, the limit tire force, and the wear state of the tire 10 stored in the storage unit 34 to the server device 7. Note that the communication unit 35 is communicatively connected to the communication network 9 by wireless or the like, and communicates with the server device 7 and further with the terminal device 8.

FIG. 4 is a block diagram showing the functional configurations of the server device 7 and the terminal device 8. As shown in FIG. The server device 7 receives tire information sent by the tire force estimating device 30 via the communication network 9. The terminal device 8 displays the tire force F, the limit tire force, and the wear state of the tire 10.

The server device 7 includes a communication section 71, a storage section 72, and a display image generation section 73. The communication unit 71 receives tire information transmitted from the vehicle via the communication network 9. The storage unit 72 is configured with a storage device such as a hard disk, and stores tire information received by the communication unit 71.

The display image generation unit 73 generates a display image by graphically representing the tire force F, the limit tire force, and the wear state of the tire 10 included in the tire information. FIG. 5 is a schematic diagram showing an example of the display image 40. The display image 40 includes a tire force image 41 that graphically represents the tire force F and the limit tire force, and a wear image 42 that graphically represents the amount of wear of the tire 10.

The display image generation unit 73 graphically represents the tire force F, the limit tire force, and the wear state of the tire 10 using a figure as a set of solids, planes, lines, points, etc., and generates the positional relationship of the tire 10 and the abstracted shape. Concepts such as these are also included in the displayed image. In the tire force image 41, for visualization, the lateral force Fy of the tire force F is plotted on the horizontal axis, and the longitudinal force Fx of the tire force F is plotted on the vertical axis. The limit tire force is also shown by a circle centered on the origin. The magnitude of the limit tire force is determined by the load Fz of the vertical component of the tire force F, and is represented by the size of a circle in the tire force image 41. The tire force F represents the current value as a plotted point. The position of the point representing the tire force F and the size of the circle representing the limit tire force change in real time in accordance with tire behavior.

The wear image 42 represents the wear state by filling in a rectangle schematically representing the tire 10 with shading. For example, a wear state with a small amount of wear may be expressed in a light shade, and a wear state with a large amount of wear may be expressed in a dark shade, or vice versa. The wear image 42 may represent the wear state by changing the color of a rectangle. Furthermore, the display image 40 represents the positional relationship of the tires 10 by schematically representing a vehicle in the center. The tire force image 41 and the wear image 42 are not limited to the example shown in FIG. 5, and may be expressed by other expression methods that indicate the position of the tire force F, the magnitude of the limit tire force, and the wear state of the tire 10. .

The display image 40 generated by the display image generation section 73 is distributed to the terminal device 8 via the communication section 71. The terminal device 8 includes a communication section 81 and a display section 82. The communication unit 81 receives the display image 40 via the communication network 9. The display unit 82 is configured with a display device such as a liquid crystal display, and displays the display image 40 received by the communication unit 81.

The terminal device 8 may receive tire information including the tire force F, the limit tire force, and the wear state of the tire 10, and may generate the display image 40 by the display image generation unit 83. In this case, the server device 7 does not need the display image generation section 73 and only needs to distribute the tire information stored in the storage section 72. In addition, the terminal device 8 receives the tire information sent by the tire force estimating device 30 at the communication section 81 without going through the server device 7, generates the display image 40 at the display image generation section 83, and generates the display image 40 on the display section 82. It may also be displayed as . Further, a display image generation section and a display section may be provided in the tire force estimating device 30 shown in FIG. 1, and the display image may be displayed within the vehicle.

Next, the operation of the tire force display system 100 will be explained. FIG. 6 is a flowchart showing the procedure for displaying the display image 40. The sensor information acquisition unit 31 of the tire force estimating device 30 starts acquiring tire physical quantities such as acceleration, tire air pressure, and tire temperature in the tire 10 measured by the sensor 20 (S1).

The tire force calculation unit 32 inputs the tire physical quantity into the calculation model 32a, and calculates the tire force F and the limit tire force (S2). The wear estimation unit 33 estimates the wear state of the tire 10 (S3). Tire information including the tire force F, the limit tire force, and the wear state of the tire 10 is transmitted and received between the tire force estimating device 30 and the server device 7 (S4). The display image generation unit 73 of the server device 7 generates a display image 40 including a tire force image 41 and a wear image 42 based on the received tire information (S5). The display unit 82 of the terminal device 8 displays the display image 40 received from the server device 7 (S6), and ends the process.

The tire force display system 100 displays the tire force F and the limit tire force, which are calculated based on the tire physical quantities measured by the sensor 20, on the display section 82, so that the behavior of the tire 10 can be more easily recognized. The tire force display system 100 can improve the recognition of the tire force F and the limit tire force by graphically representing the tire force F and the limit tire force as shown in FIG.

Furthermore, by displaying the wear state of the tire 10, the tire force display system 100 can improve the recognizability of the behavior of the tire 10, including the wear state of the tire 10. The tire force display system 100 can improve the recognition of the wear state of the tire 10 by graphically representing the tire force F and the limit tire force in shading or color as shown in FIG.

The tire force display system 100 displays a display image 40 including a tire force image 41 and a wear image 42 on a display unit 82 of a terminal device 8 that is communicatively connected via a communication network 9. The behavior of the tires 10 on the vehicle can be visually recognized.

For example, the tire force display system 100 displays the tire force F of the tire 10 mounted on a vehicle running in an automobile race as an image, thereby making it easier to visually recognize the behavior of the tire 10 on straights and corners of a circuit. do. Furthermore, the tire force display system 100 improves the visibility of the behavior of the tire 10 by displaying the tire force F of the tire 10 mounted on a vehicle running on a general road as an image. By improving the visibility of the behavior of the tires 10, the tire force display system 100 supports improvement of driving methods on driving routes, tire setting, training of driver's driving skills, communication regarding the behavior of the tires 10, etc. be able to.

Next, the characteristics of the tire force display system 100 according to the embodiment will be explained.
The tire force display system 100 according to the embodiment includes a sensor information acquisition section 31, a tire force calculation section 32, and a display section 82. The sensor information acquisition unit 31 acquires the physical quantity of the tire measured by the sensor 20 disposed on the tire 10. The tire force calculation unit 32 inputs the physical quantities of the tire acquired by the sensor information acquisition unit 31 into the calculation model 32a, and calculates the tire force F and the limit tire force. The display unit 82 displays the tire force F and the limit tire force calculated by the tire force calculation unit 32. Thereby, the tire force display system 100 can display the tire force F and the limit tire force on the display section 82, and can improve the recognition of the behavior of the tire 10.

Further, the display section 82 graphically represents the tire force F and the limit tire force. Thereby, the tire force display system 100 can improve the recognition of the tire force F and the limit tire force.

It further includes a wear estimating section 33 that estimates the wear state of the tire 10, and the display section 82 displays the wear state of the tire 10 estimated by the wear estimating section 33. Thereby, the tire force display system 100 can improve the recognition of the behavior of the tire 10 including the wear state of the tire 10.

Further, the display section 82 indicates the wear state of the tire 10 using shading or color. Thereby, the tire force display system 100 can improve the recognition of the wear state of the tire 10.

Further, the display unit 82 is provided in the terminal device 8 that is connected to the vehicle for communication by radio. Thereby, the tire force display system 100 can visually confirm the behavior of the tire 10 on the vehicle from a position away from the vehicle.

The tire force display method includes a sensor information acquisition step, a tire force calculation step, and a display step. The sensor information acquisition step acquires the physical quantity of the tire measured by the sensor 20 disposed on the tire 10. In the tire force calculation step, the physical quantities of the tire acquired in the sensor information acquisition step are input into the calculation model 32a to calculate the tire force F and the limit tire force. The display step displays the tire force F and the limit tire force calculated in the tire force calculation step. According to this tire force display method, the tire force F and the limit tire force can be displayed, and the behavior of the tire 10 can be more easily recognized.

The above description has been based on the embodiments of the present invention. Those skilled in the art will understand that these embodiments are illustrative and that various modifications and changes are possible and within the scope of the claims of the present invention. It is about to be done. Accordingly, the description and drawings herein are to be regarded in an illustrative rather than a restrictive sense.

10 tires, 20 sensors, 31 sensor information acquisition unit,
32 tire force calculation unit, 32a calculation model, 33 wear estimation unit,
82 Display unit, 100 Tire force display system.

Claims (6)

a sensor information acquisition unit that acquires a physical quantity of the tire measured by a sensor disposed on the tire;
a tire force calculation unit that calculates tire force and limit tire force by inputting the physical quantities of the tire acquired by the sensor information acquisition unit into a calculation model;
a display unit that displays the tire force and the limit tire force calculated by the tire force calculation unit;
A tire force display system comprising: The tire force display system according to claim 1, wherein the display unit graphically represents the tire force and the limit tire force. further comprising a wear estimating section for estimating a wear state of the tire,
The tire force display system according to claim 1 or 2, wherein the display section displays the wear state of the tire estimated by the wear estimation section. 4. The tire force display system according to claim 3, wherein the display unit indicates the wear state of the tire using shading or color. The tire force display system according to any one of claims 1 to 4, wherein the display unit is provided in a terminal device that is wirelessly connected to the vehicle. a sensor information acquisition step of acquiring a physical quantity of the tire measured by a sensor disposed on the tire;
a tire force calculation step of inputting the physical quantities of the tire acquired in the sensor information acquisition step into a calculation model to calculate tire force and limit tire force;
a display step of displaying the tire force and the limit tire force calculated in the tire force calculation step;
A tire force display method comprising:

Images