JP7226247B2 - vehicle - Google Patents

Description

The present invention relates to vehicles.

Patent Literature 1 discloses an eight-wheeled vehicle in which two wheels are arranged at each of the four corners. In addition, when the vehicle turns, the vehicle can turn on the spot by steering only the four wheels on the outside while keeping the four wheels on the inside out of the eight wheels.

Japanese Patent No. 06477856

However, in the vehicle described in Patent Literature 1, only four wheels are grounded when turning, so the load on the wheels increases. Also, even if eight wheels are on the ground, only four wheels are steered, so there is a possibility that the vehicle will not turn smoothly due to the frictional force generated between the non-steered wheels and the road surface.

SUMMARY OF THE INVENTION In consideration of the above facts, it is an object of the present invention to provide a vehicle that can be smoothly turned in a configuration having eight or more wheels.

The vehicle according to claim 1 comprises a pair of left and right first wheels provided at both ends of the vehicle in the front-rear direction, and a second wheel arranged adjacent to each of the first wheels on the inside in the front-rear direction of the vehicle. a vehicle speed sensor for detecting a vehicle speed; a steering angle sensor for detecting a steering angle; When calculating the turning radius of the first wheel positioned on the outer side , and when the turning radius is smaller than a predetermined threshold value, the actual steering angle of the first wheel is larger than the actual steering angle of the second wheel. and a control unit that controls the rudder angles of the first wheel and the second wheel to increase.

In the vehicle according to claim 1, a pair of left and right first wheels are provided at both ends of the vehicle in the front-rear direction. Further, second wheels are arranged adjacent to the inner side in the vehicle front-rear direction with respect to each of the first wheels. For this purpose, the vehicle has four first wheels and four second wheels. Further, it comprises a vehicle speed sensor for detecting vehicle speed, a steering angle sensor for detecting steering angle, and a control unit for controlling steering angles of the first wheel and the second wheel.

Here, the control unit calculates the turning radius of the vehicle during turning based on the vehicle speed detected by the vehicle speed sensor during turning of the vehicle and the steering angle detected by the steering angle sensor. Further, the control unit controls the actual steering angle of the first wheels to be larger than the actual steering angle of the second wheels when at least one of the vehicle speed during turning of the vehicle and the turning radius is smaller than a predetermined threshold value. It controls the rudder angles of the first and second wheels. As a result, even when the vehicle is turned with eight wheels on the ground, the frictional force generated between each wheel and the road surface can be reduced.

As explained above, according to the vehicle according to the present invention, it is possible to turn smoothly in a configuration having eight or more wheels.

1 is a side view of a vehicle according to an embodiment; FIG. It is a schematic bottom view for demonstrating the angle of the wheel in embodiment. 1 is a block diagram showing the hardware configuration of a vehicle according to an embodiment; FIG. 1 is a block diagram showing the functional configuration of a vehicle according to an embodiment; FIG. It is a flow chart which shows a flow of steering angle control processing in an embodiment. It is a schematic bottom view of a vehicle which shows the first modification of steering angle control processing in the embodiment. It is a schematic bottom view of a vehicle which shows the second modification of the steering angle control process in the embodiment.

A vehicle 10 according to an embodiment will be described with reference to the drawings. An arrow FR, an arrow UP, and an arrow RH, which are appropriately shown in each drawing, indicate the upward, upward, and rightward directions of the vehicle, respectively. In the following description, when simply using the front-rear, up-down, and left-right directions, the front-rear direction of the vehicle, the up-down direction of the vehicle, and the left-right direction when facing the front direction of the vehicle are indicated unless otherwise specified. .

As shown in FIG. 1, a vehicle 10 according to this embodiment includes a substantially box-shaped vehicle body 12 . The vehicle 10 is an electric vehicle having a front-rear symmetrical structure, and is configured to be able to travel in any direction in the front-rear direction. Therefore, in the following description, one side in the vehicle front-rear direction will be referred to as the vehicle front side for convenience, and the other side in the vehicle front-rear direction will be referred to as the vehicle rear side for convenience.

A vehicle body 12 constituting the vehicle 10 is configured by connecting a first vehicle body unit 14, a second vehicle body unit 16, a third vehicle body unit 18, and a fourth vehicle body unit 20 in order from the front side of the vehicle. The first vehicle body unit 14 has a lower portion that bulges toward the front of the vehicle. and are provided. Further, a first display portion 14A is provided on the side surface of the first vehicle body unit 14, and is configured so that an image can be displayed on the first display portion 14A.

The second vehicle body unit 16 is formed in a substantially rectangular shape when viewed from the side. A second display portion 16A having a substantially rectangular shape as viewed from the side is provided on the side surface of the second vehicle body unit 16 . The second display section 16A is configured so as to be continuous with the first display section 14A, so that images can be displayed.

The third vehicle body unit 18 has substantially the same outer shape as the second vehicle body unit 16, and a third display section 18A is provided on the side surface of the third vehicle body unit 18 so as to be continuous with the second display section 16A. ing. An image can be displayed on the third display section 18A.

The fourth vehicle body unit 20 has an external shape that is symmetrical in the longitudinal direction with respect to the first vehicle body unit 14, and has a lower portion that protrudes toward the rear side of the vehicle. A first rear wheel 28 as a first wheel and a second rear wheel 26 as a second wheel are provided in this bulging portion. Further, a fourth display section 20A is provided on the side surface of the fourth vehicle body unit 20 so as to be continuous with the third display section 18A, and is configured so that an image can be displayed on the fourth display section 20A. . In this embodiment, the first display section 14A, the second display section 16A, the third display section 18A, and the fourth display section 20A are provided on both side surfaces of the vehicle body 12 as an example.

As shown in FIG. 2, the vehicle 10 is provided with eight wheels. A pair of left and right first front wheels 22 are provided at the front end portion of the vehicle 10, and a second front wheel 24 is provided adjacent to each of the first front wheels 22 on the vehicle rear side (vehicle front-rear direction inner side). It is That is, the second front wheel 24L is provided on the vehicle rear side of the first front wheel 22L on the left side of the vehicle, and the second front wheel 24R is provided on the vehicle rear side of the first front wheel 22R on the right side of the vehicle.

On the other hand, a pair of left and right first rear wheels 28 are provided at the rear end portion of the vehicle 10 . Two rear wheels 26 are provided. That is, the second rear wheel 26L is provided on the vehicle front side of the first rear wheel 28L on the left side of the vehicle, and the second rear wheel 26R is provided on the vehicle front side of the first rear wheel 28R on the right side of the vehicle. there is Here, in this embodiment, the steering angles of the first front wheel 22, the second front wheel 24, the first rear wheel 28, and the second rear wheel 26 are configured to be controlled independently.

Here, in this embodiment, redundancy design is made possible by diverting two sets or four sets of the system of the base vehicle. Specifically, four sets of front suspensions, two sets of front corner brakes, two sets of corner brakes with a parking function, and four sets of steering mechanisms are used. Eight sets of wheels and tires are also used. Further, the vehicle 10 employs linkless steer-by-wire.

FIG. 3 is a block diagram showing the hardware configuration of the vehicle 10. As shown in FIG. As shown in FIG. 3, the vehicle 10 includes an ECU (Electrical Control Unit) 30 as a control section.

The ECU 30 includes a CPU (Central Processing Unit: processor) 32 , a ROM (Read Only Memory) 34 , a RAM (Random Access Memory) 36 , a storage 38 and an input/output interface 40 . Each component is communicatively connected to each other via a bus 42 .

The CPU 32 is a central processing unit that executes various programs and controls each section. That is, the CPU 32 reads a program from the ROM 34 or the storage 38 and executes the program using the RAM 36 as a work area. The CPU 32 performs control of the above components and various arithmetic processing according to programs recorded in the ROM 34 or the storage 38 .

The ROM 34 stores various programs and various data. RAM 36 temporarily stores programs or data as a work area. The storage 38 is configured by a HDD (Hard Disk Drive) or SSD (Solid State Drive) and stores various programs including an operating system and various data.

A first front wheel steering mechanism 44, a second front wheel steering mechanism 46, a first rear wheel steering mechanism 48, a second rear wheel steering mechanism 50, a vehicle speed sensor 52, and a steering angle sensor 54 are connected to the input/output interface 40. ing.

The first front wheel steering mechanism 44 is a mechanism that steers the first front wheel 22L and the first front wheel 22R, and steers the first front wheel 22L and the first front wheel 22R by a predetermined angle based on a signal from the ECU 30. . The second front wheel steering mechanism 46 is a mechanism that steers the second front wheels 24L and the second front wheels 24R, and steers the second front wheels 24L and the second front wheels 24R by a predetermined angle based on a signal from the ECU 30. .

The first rear wheel steering mechanism 48 is a mechanism for steering the first rear wheel 28L and the first rear wheel 28R. steer the The second rear wheel steering mechanism 50 is a mechanism for steering the second rear wheel 26L and the second rear wheel 26R, and based on a signal from the ECU 30, the second rear wheel 26L and the second rear wheel 26R are rotated by a predetermined angle. steer the

The vehicle speed sensor 52 is mounted on the vehicle 10 and detects the speed of the vehicle 10 (that is, vehicle speed). A steering angle sensor 54 is mounted on the vehicle 10 to detect the steering angle. The steering angle referred to here refers to the steering angle of the steering wheel during manual operation. Also, during automatic driving or in the case of a vehicle without a driver's seat, it refers to the steering angle calculated based on the course of the vehicle 10 .

The vehicle 10 implements various functions using the hardware resources shown in FIG. A functional configuration realized by the vehicle 10 will be described with reference to FIG.

As shown in FIG. 4, the vehicle 10 includes a vehicle speed acquisition section 60, a steering angle acquisition section 62, a turning radius calculation section 64, and a steering angle control section 66 as functional configurations. Each functional configuration is realized by the CPU 32 of the ECU 30 reading and executing a program stored in the ROM 34 or the storage 38 .

The vehicle speed acquisition unit 60 acquires the speed of the vehicle 10 detected by the vehicle speed sensor 52 . The steering angle acquisition section 62 acquires the steering angle detected by the steering angle sensor 54 .

The turning radius calculation unit 64 calculates the turning radius of the vehicle 10 during turning based on the vehicle speed acquired by the function of the vehicle speed acquisition unit 60 when the vehicle 10 turns and the steering angle acquired by the function of the steering angle acquisition unit 62. Calculate The term "turning radius" as used herein refers to the radius of a circle drawn by the center of the outer tire during turning. As shown in FIG. 2, in this embodiment, when the vehicle 10 turns to the left, the radius of the circle drawn by the center of the first front wheel 22R is calculated as the turning radius.

As shown in FIG. 3, the steering angle control section 66 controls the steering angles of the first front wheel 22, the second front wheel 24, the first rear wheel 28 and the second rear wheel 26. As shown in FIG. Specifically, the steering angle control unit 66 controls the actual steering angle of the first front wheels 22 to be greater than the actual steering angle of the second front wheels 24 when at least one of the vehicle speed and the turning radius during turning is smaller than a predetermined threshold value. Also, the steering angle is controlled so that the actual steering angle of the first rear wheel 28 becomes larger than the actual steering angle of the second rear wheel 26.例文帳に追加

(action)
Next, the operation of this embodiment will be described.

(Example of steering angle control processing)
FIG. 5 is a flowchart showing an example of the flow of steering angle control processing by the vehicle 10. As shown in FIG. This steering angle control process is executed by the CPU 32 reading out a program from the ROM 34 or the storage 38, developing it in the RAM 36, and executing it.

The CPU 32 determines whether or not the vehicle 10 is turning in step S102. Specifically, the CPU 32 determines that the vehicle is turning when the steering angle is greater than a predetermined angle.

When the CPU 32 determines in step S102 that the vehicle 10 is turning, the process proceeds to step S104. If the CPU 32 determines in step S102 that the vehicle 10 is not turning, it terminates the steering angle control process.

The CPU 32 acquires the vehicle speed V in step S104. Specifically, the CPU 32 acquires the vehicle speed V detected by the vehicle speed sensor 52 using the function of the vehicle speed acquisition unit 60 .

The CPU 32 acquires the steering angle θ in step S106. Specifically, the CPU 32 acquires the steering angle θ detected by the steering angle sensor 54 using the function of the steering angle acquisition section 62 . In this embodiment, as an example, the steering angle θ is obtained immediately after obtaining the vehicle speed V, but the present invention is not limited to this, and the steering angle θ may be obtained first.

In step S108, the CPU 32 determines whether the vehicle speed V is smaller than the threshold value Va and the turning radius R is smaller than the threshold value Ra. Then, when both relationships are satisfied, the CPU 32 proceeds to the process of step S110. Further, the CPU 32 terminates the steering angle control process when the vehicle speed V is equal to or greater than the threshold value Va and/or when the turning radius R is equal to or greater than the threshold value Ra. Note that the turning radius R is calculated based on the vehicle speed V and the steering angle θ.

The CPU 32 controls the steering angle in step S110. Specifically, the steering angle is controlled so that the actual steering angle θ1 of the first front wheels 22 becomes larger than the actual steering angle θ2 of the second front wheels 24, and the actual steering angle θ3 of the first rear wheels 28 becomes The steering angle of each wheel is controlled so as to be larger than the actual steering angle θ4 of the second rear wheel 26. - 特許庁Then, the CPU 32 terminates the steering angle control process.

As described above, in this embodiment, even when the vehicle 10 is turned with eight wheels on the ground, the frictional force generated between each wheel and the road surface can be reduced. That is, when the actual steering angles of the first front wheel 22 and the second front wheel 24 are set to the same angle, the trajectories of the tires of the first front wheel 22 and the second front wheel 24 are different. Frictional force may increase. In contrast, by controlling the steering angle as in this embodiment, the frictional force generated between each wheel and the road surface can be reduced. As a result, the vehicle 10 having eight or more wheels can be smoothly turned.

In addition, the vehicle 10 of the present embodiment can control the steering angle like the modified examples shown in FIGS. 6 and 7 .

(first modification)
FIG. 6 shows steering angle control when the vehicle 10 is pulled over to the road shoulder. As shown in FIG. 6, in this modification, the steering angle control unit 66 sets the steering angles of the first front wheel 22, the second front wheel 24, the first rear wheel 28, and the second rear wheel 26 to the same steering angle. Control.

For example, when it is desired to move the vehicle 10 obliquely to the left front, the first front wheel 22, the second front wheel 24, the first rear wheel 28 and the second rear wheel 26 are turned to the left at the same steering angle. As a result, the vehicle 10 can be translated obliquely to the left front as indicated by the arrow in the figure.

(Second modification)
FIG. 7 shows steering angle control when some wheels of the vehicle 10 have failed. As shown in FIG. 7, in this modified example, the second front wheel 24 is broken and does not move. Two rear wheels 26 are controlled.

In addition, you may provide the raising/lowering mechanism which raises/lowers each wheel. In this case, by raising the malfunctioning second rear wheel 26, it can be lifted off the road surface, and no frictional force is generated between the road surface and the second front wheel 24 during turning. That is, the vehicle 10 can be smoothly turned even when some wheels are out of order.

Although the embodiments and modifications have been described above, it is needless to say that the present invention can be embodied in various forms without departing from the gist of the present invention. For example, in the above embodiment, the steering angle of each wheel is controlled when the vehicle speed V is smaller than the threshold value Va and the turning radius R is smaller than the threshold value Ra, but the present invention is not limited to this. That is, only the vehicle speed V is detected, and the steering angle is controlled so that the actual steering angle θ1 of the first front wheels 22 becomes larger than the actual steering angle θ2 of the second front wheels 24 when the vehicle speed V is smaller than the threshold value Va. Moreover, the steering angle of each wheel may be controlled such that the actual steering angle θ3 of the first rear wheel 28 is greater than the actual steering angle θ4 of the second rear wheel 26 . Further, only the turning radius R is detected, and when the turning radius R is smaller than the threshold value Ra, the steering angle is adjusted so that the actual steering angle θ1 of the first front wheels 22 is greater than the actual steering angle θ2 of the second front wheels 24. In addition, the steering angle of each wheel may be controlled such that the actual steering angle θ3 of the first rear wheel 28 is greater than the actual steering angle θ4 of the second rear wheel 26 .

Further, in the above embodiment, the invention is applied to the vehicle 10 having eight wheels, but the invention is not limited to this. For example, it may be applied to vehicles having ten or more wheels.

Further, the processing executed by the CPU 32 by reading the software (program) in the above embodiment may be executed by various processors other than the CPU. The processor in this case is a PLD (Programmable Logic Device) whose circuit configuration can be changed after manufacturing such as an FPGA (Field-Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit) for executing specific processing. A dedicated electric circuit, which is a processor having a specially designed circuit configuration, is exemplified. Further, the above processing may be executed by one of these various processors, or a combination of two or more processors of the same or different type (for example, a plurality of FPGAs, a combination of a CPU and an FPGA, etc.). ) can be run. Further, the hardware structure of these various processors is, more specifically, an electric circuit in which circuit elements such as semiconductor elements are combined.

Furthermore, in the above embodiment, the storage 38 is used as a recording unit, but the present invention is not limited to this. For example, a recording medium such as a CD (Compact Disk), a DVD (Digital Versatile Disk), and a USB (Universal Serial Bus) memory may be used as the recording unit.

10 vehicle 22 first front wheel (first wheel)
24 second front wheel (second wheel)
26 second rear wheel (second wheel)
28 first rear wheel (first wheel)
30 ECU (control unit)
52 vehicle speed sensor 54 steering angle sensor

Claims (2)

A pair of left and right first wheels provided at both ends in the front-rear direction of the vehicle;
a second wheel arranged adjacent to each of the first wheels on the inner side in the vehicle front-rear direction;
a vehicle speed sensor for detecting vehicle speed;
a steering angle sensor that detects a steering angle;
During turning of the vehicle, based on the detected values of the vehicle speed sensor and the steering angle sensor , the turning radius of the first wheel positioned on the outer side during turning among the first wheels on the traveling direction side is calculated, and the turning radius of the first wheel is calculated. Control for controlling the steering angles of the first and second wheels so that the actual steering angle of the first wheel is greater than the actual steering angle of the second wheel when the diameter is smaller than a predetermined threshold. Department and
vehicle with A lifting mechanism for lifting and lowering the first wheel and the second wheel respectively,
2. The vehicle according to claim 1, wherein one of the first wheel and the second wheel, which has failed, is lifted off the road surface.

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