Road condition acquisition system

Abstract

To ensure that a road surface condition within an area is acquired satisfactorily.SOLUTION: A road surface condition, which is a condition of a road surface, is acquired for each of a plurality of moving objects, and moving object information including road surface condition information, which is information for representing the road surface condition, is transmitted. A central control device receives the moving object information and transmits central control information including a movement command to at least one of the plurality of moving objects based on the moving object road surface condition information included in the moving object information. The central control device, for example, forms the movement command so that the road surface condition is acquired in good condition. Then, at least one of the moving objects moves according to the movement command, acquires the road surface condition, and transmits the road surface condition information. The central control device receives the moving object information and acquires the road surface condition. In this way, based on the road surface condition information from the moving object which has moved according to the movement command formed by the central control device, it is possible to acquire the road surface condition within the area satisfactorily.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a road surface condition acquisition system for acquiring the condition of a road surface. [Background technology]

[0002] Patent Document 1 describes that wireless communication is performed between a transport vehicle, which is a vehicle that performs mining work, and a control terminal, and that the control terminal creates map information based on information from the transport vehicle (the location of the transport vehicle, a value indicating the deterioration state of the road surface, and the time). The transport vehicle also acquires map information stored in the control terminal and travels based on the map information. For example, the transport vehicle determines whether it is possible to travel the planned travel course based on the map information, and performs steering to avoid obstacles or travels at a reduced speed based on the determination result. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2020-50193 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a road surface condition acquisition system that acquires road surface conditions, which are the conditions of the road surface within an area in which a mobile object moves, so that the road surface conditions can be acquired in a good condition.

[0005] In the road surface condition acquisition system according to the present invention, road surface conditions are acquired for each of a plurality of moving bodies, and moving body information including road surface condition information representing the road surface conditions is created and transmitted. A central control device receives the moving body information, and creates and transmits central control information including a movement command to at least one of the plurality of moving bodies based on the road surface condition information included in the moving body information.

[0006] The central control device can, for example, create a movement command so that the road surface condition is acquired satisfactorily. The mobile object moves according to the movement command, acquires the road surface condition, creates mobile object information including the road surface condition information, and transmits it. The central control device receives the mobile object information and acquires the road surface condition. In this way, based on the road surface condition acquired by the mobile object that moves according to the movement command created by the central control device, the road surface condition within the area can be acquired satisfactorily.

[0007] The central control device can also generate a movement command for a moving body that moves toward a part of the road surface with large unevenness or a part of the road surface with a low friction coefficient among the multiple moving bodies to avoid the part or to move at a reduced speed. As a result, the safety of each of the multiple moving bodies can be improved. Also, each of the multiple moving bodies can be made less likely to get stuck, and a decrease in work efficiency within the area can be effectively suppressed. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram conceptually illustrating a road surface condition acquisition system according to an embodiment of the present invention, the road surface condition acquisition system including a management system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram conceptually showing a drive / transmission device, a braking device, and a steering device provided on a vehicle as a moving body included in the road surface condition acquisition system. [Diagram 3] 2 is a diagram conceptually showing the periphery of a control device of the road surface condition acquisition system. FIG. [Figure 4] 1A is a diagram showing a change in longitudinal force acting between a wheel and a road surface over time, and FIG. 1B is a diagram showing the relationship between the longitudinal force acting between a wheel and a road surface and the slip ratio. [Diagram 5] 4 is a flowchart showing a vehicle μ acquisition program stored in the vehicle ECU of the road surface condition acquisition system. [Figure 6]5 is a flowchart showing a vehicle information creation program stored in the vehicle ECU. [Figure 7] 4 is a flowchart showing a remote control program stored in the vehicle ECU. [Figure 8] 5 is a flowchart showing a central control information creation program stored in a central control ECU of the road surface condition acquisition system. [Figure 9] 4 is a flowchart showing a management program stored in the central control ECU. [Figure 10] 6 is a flowchart showing another road surface μ related state acquisition program stored in the vehicle ECU. [Figure 11] FIG. 4 is a diagram conceptually showing another drive and transmission device included in the vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A road surface condition acquisition system according to an embodiment of the present invention will now be described with reference to the drawings. The road surface condition acquisition system includes a management system. EXAMPLES

[0010] 1, the road surface condition acquisition system according to this embodiment includes vehicles V, which are multiple moving objects performing work in a mine or the like, a central control device C capable of communicating with the vehicles V, and one or more antennas A. Wireless communication is performed between the multiple vehicles V and the central control device C directly or via the antenna A. Most of the multiple vehicles V are of the same type and model.

[0011] Each of the vehicles V includes four wheels 10FL, 10FR, 10RL, and 10RR located on the front, rear, left, and right sides as shown in Fig. 2. These four wheels 10FL, 10FR, 10RL, and 10RR are driving wheels, and each of the vehicles V is a four-wheel drive vehicle. In addition, the left and right front wheels 10FL and 10FR are steering wheels, and each of the vehicles V is a front-wheel steering vehicle. Furthermore, each of the multiple vehicles V is an autonomous vehicle capable of autonomous driving, but is not limited thereto. Each of the multiple vehicles V may be a manually driven vehicle capable of manual driving, or a vehicle that can be switched between an autonomous driving state and a manual driving state. Also, each of the multiple vehicles V may be in a manned driving state or an unmanned driving state.

[0012] Hereinafter, with regard to wheels, brakes, etc., the suffixes FL, FR, RL, RR, F, and R indicating the wheel positions will be omitted when referring to them collectively or when the wheel positions are not specified.

[0013] As shown in FIG. 2, each of the plurality of vehicles V includes a drive / transmission device D, a braking device B, a steering device ST, and the like.

[0014] The drive and transmission device D transmits drive torque output by a drive source 13 including an engine 11 and an electric motor 12 to the front, rear, left and right wheels 10 which are drive wheels. The drive and transmission device D includes the drive source 13, a main transmission path 16 which transmits the drive torque of the drive source 13 to the left and right front wheels 10FL, 10FR, and a sub-transmission path 18 which transmits the drive torque of the drive source 13 to the left and right rear wheels 10RL, 10RR.

[0015] The main transmission path 16 includes a transmission 20 connected to the drive source 13, a front wheel differential 22, and drive shafts 24FL, 24FR connected to the left and right front wheels 10FL, 10FR. The secondary transmission path 18 includes the transmission 20, a transfer 26, a propeller shaft 28, a rear wheel differential 30, and drive shafts 32RL, 32RR connected to the left and right rear wheels 10RL, 10RR.

[0016] In addition to the engine 11 and the electric motor 12, the drive source 13 includes a power split mechanism 34, a generator 35, inverters 36M, 36G, and the like. The power split mechanism 34 splits the rotation of the engine 11 into the rotation of the generator 35 and the rotation of an output shaft of the power split mechanism 34, and the transmission 20 is provided on the output shaft of the power split mechanism 34. The electric motor 12 is connected to the transmission 20, and the output shaft of the transmission 20 is connected to the left and right front wheels 10FL, 10FR via the front wheel side differential 22 and the drive shafts 24FL, 24FR. The generator 35 and the electric motor 12 are connected to a battery 38 via inverters 36G, 36M, respectively. The battery 38 supplies electric energy to the electric motor 12 and the like, and the battery 38 stores electric energy obtained by the electric motor 12 and the generator 35. The operation of the generator 35 and the electric motor 12 is controlled by controlling the inverters 36M, 36G, respectively.

[0017] The transfer 26 distributes the output of the drive source 13 to the left and right rear wheels 10RL, 10RR. The transfer 26 and other components switch between a state in which the output of the drive source 13 is transmitted to the front, rear, left and right four wheels 10FL, 10FR, 10RL, 10RR (four-wheel drive state) and a state in which the output is transmitted to the left and right front wheels 10FL, 10FR (two-wheel drive state). The front wheel differential 22 and the rear wheel differential 30 may each include, for example, a differential gear device.

[0018] In the four-wheel drive state, the driving torque of at least one of the engine 11 and the electric motor 12 is transmitted to the four front, rear, left and right wheels 10FL, 10FR, 10RL and 10RR, and in the two-wheel drive state, it is transmitted to the left and right front wheels 10FL and 10FR. In addition, regenerative braking torque is applied to the four front, rear, left and right wheels 10FL, 10FR, 10RL and 10RR or the left and right front wheels 10FL and 10FR by regenerative braking of the electric motor 12. For this reason, the driving source 13 can be considered as a regenerative braking device.

[0019] The braking device B includes the regenerative braking device 13, a hydraulic braking device 41 as a friction braking device, and the like. The hydraulic braking device 41 includes a hydraulic brake 40 as a friction brake provided on each of the multiple wheels 10, a hydraulic control actuator 46, and the like. Each hydraulic brake 40 includes a brake rotor 42 that can rotate integrally with the wheel 10, a pair of friction engagement members 43 provided opposite the brake rotor 42, and a pressing device 44 that presses the pair of friction engagement members 43 against the brake rotor 42 by hydraulic pressure. A hydraulic control actuator 46 is connected to each pressing device 44 of the multiple hydraulic brakes 40. The hydraulic control actuator 46 generates hydraulic pressure and can control the hydraulic pressure of the hydraulic brakes 40 of each of the front, rear, left, and right wheels 10 separately and independently.

[0020] The steering device ST is provided to connect the left and right front wheels 10FL, 10FR, and steers the pair of left and right front wheels 10 by moving a steering shaft in the left and right direction of the vehicle. The left and right front wheels 10FL, 10FR are respectively connected by knuckle arms 52FL, 52FR of knuckles (not shown) that hold the wheels, tie rods 54FL, 54FR, a steering shaft 56, etc., and a steering actuator 60 is provided on the steering shaft 56. The steering actuator 60 includes an electric motor (not shown) and a motion conversion mechanism that converts rotation of the electric motor into movement in the axial direction of the steering shaft 56 (the width direction of the vehicle). The steering actuator 60 moves the steering shaft 54 ​​in the axial direction relative to the vehicle body, thereby steering the pair of left and right front wheels 10. The steering angles of the left and right front wheels 10 are determined by the operating state of the steering actuator 60.

[0021] As shown in Fig. 3, each of the multiple moving bodies V includes a vehicle ECU 80 mainly composed of a computer. The vehicle ECU 80 includes an identification information storage unit 82, a moving body road surface condition acquisition unit (hereinafter simply referred to as a road surface condition acquisition unit) 84, a travel control unit 86, a vehicle information creation unit 88 that creates vehicle information as moving body information, and the like. The vehicle ECU 80 is also connected with wheel speed sensors 90FL, 90FR, 90RL, 90RR that are provided on the front, rear, left and right wheels 10 and detect the rotation speeds of the wheels 10, a yaw rate sensor 92 that detects the yaw rate that is the rotation angular velocity about the vertical axis of the vehicle V, a G sensor 94 that is an acceleration sensor that detects the acceleration in the front-rear and lateral directions of the vehicle V, and the like, as well as an engine 11, an inverter 36M, a transfer 26, and the like of the drive / transmission device D, a hydraulic control actuator 46 of the hydraulic braking device 41 of the braking device B, a regenerative braking device 13, a steering actuator 60 of the steering device ST, and the like. Also connected are a surrounding information acquisition device 102, a GPS (Global Positioning System) receiver 104, a notification device 106, a vehicle communication device 108 as a mobile communication device, and a number of other measuring devices 110, etc.

[0022] The surrounding information acquisition device 102 includes a camera, a radar device, etc., and identifies objects around the host vehicle, which is the vehicle V, and acquires the relative positional relationship between the objects and the host vehicle, etc. The camera, radar device, etc. can also acquire the condition of the road surface. The GPS receiver 104 receives a GPS signal, and the position of the host vehicle, which is the vehicle V, is obtained based on the received signal. The plurality of measuring devices 110 include a device that measures the state of charge of the battery 38, a device that measures the amount of fuel in the fuel tank, and the like.

[0023] The vehicle communication device 108 transmits vehicle information as moving body information, which is information created in the vehicle V, and receives central control information, which is information transmitted from the central control device C. The moving body information and central control information are often transmitted and received via an antenna A. The notification device 106 includes, for example, a display, an audio output device, etc., and can notify the contents of the central control information received from the central control device C by the vehicle communication device 108.

[0024] The identification information storage unit 82 stores identification information and the like set for the vehicle V. Each of the multiple vehicles V is given different identification information and is managed based on the identification information. In addition, the weight, position, and the like of the cargo (luggage) carried by each of the vehicles V are also stored in the identification information storage unit 82 in association with the identification information.

[0025] The driving control unit 86 controls the engine 11, transfer 26, inverter 36M of the drive / transmission device D, the hydraulic control actuator 46 of the braking device B, the regenerative braking device 13, the steering actuator 60 of the steering device ST, and the like, to control the driving state of the vehicle V. The driving control unit 86 controls these based on the relative positional relationship between the host vehicle and surrounding objects acquired by the surrounding information acquisition device 102, controls the host vehicle V to travel along a predetermined route, and controls based on a driving command as a movement command included in the central control information.

[0026] The road surface condition acquisition unit 84 acquires, as the road surface condition, road surface μ, which is the friction coefficient of the road surface on which the vehicle V runs, or a condition related to the road surface μ (collectively referred to as a road surface μ-related condition, etc.). The road surface μ-related condition, etc., can be expressed by road surface μ, or a condition in which the road surface μ is small, or a condition in which the road surface μ is large, etc.

[0027] In this embodiment, the road surface condition acquisition unit 84 acquires road surface μ as the road surface μ-related condition. As shown in Figures 4(a) and (b), the road surface μ is obtained by dividing the longitudinal force F when the longitudinal force (which can be called a frictional force) acting between the wheel 10 and the road surface becomes saturated by the load N of the wheel 10. μ=F / N The saturated longitudinal force is the maximum friction force. The saturated longitudinal force can be obtained based on the driving torque applied to the wheels 10 by the drive / transmission device D and the braking torque applied by the braking device B when the slip ratio reaches a set value Sa, in other words, the operating states of the engine 11 and the electric motor 12, the operating state of the hydraulic control actuator 46, etc.

[0028] 4(a) and (b), as the braking torque applied to the wheel 10 by the braking device B and the braking torque applied to the wheel 10 by the drive and transmission device D increase, the longitudinal force (frictional force) acting between the wheel 10 and the road surface increases, and the slip ratio becomes larger. However, when the longitudinal force reaches the maximum frictional force, the longitudinal force does not increase even if the drive torque or braking torque increases, and the slip ratio reaches the set value Sa. As described above, the longitudinal force (frictional force) is approximately proportional to the driving torque or braking torque until the longitudinal force (frictional force) reaches the maximum frictional force. Therefore, the longitudinal force (frictional force) can be obtained based on the driving torque or braking torque, i.e., the operating states of the engine 11 and the electric motor 12, the operating state of the hydraulic control actuator 46, etc. However, after the longitudinal force reaches the saturated longitudinal force, it is difficult to estimate the frictional force based on the driving torque or braking torque.

[0029] Therefore, in this embodiment, when the slip ratio reaches the set value Sa, the maximum friction force, which is the saturated longitudinal force, is obtained based on the state of the drive / transmission device D and the braking device B, and the road surface μ is obtained.

[0030] Furthermore, the slip ratio Sij can be expressed by the following equation, where vs is the vehicle running speed and vw is the wheel speed (circumferential speed). Sij=(vs-vwij) / vs In the above formula, the braking slip ratio is expressed as a positive value, and the driving slip ratio is expressed as a negative value. The running speed vs of the vehicle V can be obtained based on the maximum detection value of the four wheel speed sensors 90FL, 90FR, 90RL, and 90RR on the front, rear, left, and right.

[0031] In this embodiment, the road surface μ is obtained by executing a road surface μ obtaining program shown in the flow chart of FIG. In step 1 (hereinafter abbreviated as S1, the same applies to the other steps), the running speed vs of the vehicle V is obtained based on the detection value of the wheel speed sensor 90, and the slip ratio Sij (i=F, R, j=L, R) as the slip state is obtained for each wheel 10 based on the running speed vs and the wheel speed vwij of each wheel 10. In S2, it is determined whether the absolute value of the slip ratio Sij is equal to or greater than a set value Sa.

[0032] If the determination in S2 is YES, then in S3 it is determined whether the absolute value of the slip ratio Sij was smaller than the set value Sa in the previous time. In other words, in S2, 3 it is determined whether the absolute value of the slip ratio Sij is equal to or larger than the set value Sa for the first time this time. If the determination in S2, 3 is YES, then in S4 the longitudinal force applied to the wheel 10 is acquired. As the longitudinal force, the braking force is acquired based on at least one of the regenerative braking torque and the hydraulic braking torque (specifically, at least one of the regenerative braking torque determined by the operating state of the inverter 36M and the hydraulic pressure of the pressing device 44 controlled by the hydraulic control actuator 46), and the driving force as the longitudinal force is acquired based on the driving torque (specifically, the operating state of the electric motor 12 based on the control of the inverter 36M, the operating state of the engine 11, etc.). In S5, the load N applied to the wheel 10 is acquired. The load N applied to each wheel 10 is obtained based on the known vehicle weight, load, position of the load (luggage), amount of fuel, driver weight and position (driver weight and position are considered in a manned driving state), etc. Then, in S6, the maximum friction force F, which is the longitudinal force applied to the wheel 10, is divided by the load N applied to the wheel 10 to obtain the friction coefficient μ. μ=F / N

[0033] The road surface μ can be obtained by dividing the detection value α of the G sensor 94 by the gravitational acceleration g when the absolute value of the slip ratio Sij becomes larger than the set value Sa. M is the mass of the vehicle V. α=F / M μ=α / g

[0034] In addition, when obtaining road surface μ when the vehicle V is in a turning state, the lateral force acting on the vehicle V (which can be obtained based on the detection value of the G sensor 94, etc.) is obtained, and the resultant force of the lateral force and the longitudinal force is obtained as the maximum frictional force, thereby obtaining the road surface μ. (front and back force) 2 +(lateral force) 2 =(maximum friction force) 2

[0035] The vehicle information creation unit 88 creates vehicle information including road surface μ information as road surface condition information, identification information, and vehicle position information as moving body position information acquired based on a signal received via the GPS receiver 104. The created vehicle information is supplied to the vehicle communication device 108, and is transmitted by the vehicle communication device 108.

[0036] A vehicle information creation program represented by the flowchart of FIG. In S11, road surface μ information is acquired, in S12, wheel position information (e.g., FR, etc.) which is information indicating the position of the wheel 10 at which the absolute value of the slip ratio Sij becomes equal to or greater than the set value Sa is acquired, and in S13, vehicle position information is acquired. In addition, in S14, identification information ID is read. Then, in S15, vehicle information including the identification information, vehicle position information, road surface μ, wheel position information, etc. is created, and in S16, the vehicle information is supplied to the vehicle communication device 108. The vehicle communication device 108 transmits the vehicle information.

[0037] 3, the central control device C includes a central control ECU 150 mainly composed of a computer, a central communication device 152, a map information storage unit 154, etc. The central control ECU 150 includes a travel command creation unit 156 as a movement command creation unit, a map information creation unit 158, a work plan storage unit 160 which is an example of a movement plan information storage unit, etc. The driving command generating unit 156 generates a driving command as a movement command for the vehicle V based on the vehicle information received by the central communication device 152.

[0038] For example, the vehicle that transmitted the vehicle information (for example, the first vehicle V1 as the first moving body; see FIG. 1) is determined from the identification information (for example, ID1) included in the vehicle information. Also, if the road surface μ represented by the road surface μ information included in the vehicle information is smaller than a set μ value, a driving command is generated for the second vehicle V2 as the second moving body that is following the first vehicle V1. The vehicle following the first vehicle V1 refers to the vehicle that is scheduled to next travel on a road surface whose road surface μ is detected by the first vehicle V1 to be smaller than the set μ value.

[0039] A travel command (braking control command) for controlling the braking torque applied to the wheel 10 at a position determined by the wheel position information included in the vehicle information can be generated for the second vehicle V2. For example, the braking torque applied to the wheel 10 of the second vehicle V2 can be made smaller than the braking torque applied to the first vehicle V1. As described above, the road surface μ is acquired based on the saturated longitudinal force, but it is difficult to accurately acquire the point in time when the absolute value of the slip ratio Sij reaches the set value Sa. Therefore, the braking torque applied to the wheel 10 of the second vehicle V2 is made smaller than the braking torque applied to the first vehicle V1, so that the braking torque at the point in time when the absolute value of the slip ratio Sij first reaches the set value Sa can be acquired with high accuracy. As a result, the road surface μ of the road surface detected by the first vehicle V1 as having a small road surface μ can be acquired with high accuracy. On the other hand, the braking torque applied to the wheel 10 of the second vehicle V2 can be made larger than the braking torque applied to the first vehicle V1, because the slip state of the wheel 10 can be accurately detected.

[0040] In addition, in the case where the absolute value of the slip ratio Sij becomes equal to or greater than the set value Sa while both hydraulic braking torque and regenerative braking torque are being applied in the first vehicle V1, a travel command (braking control command) can be generated so that the hydraulic braking torque is set to 0 and regenerative braking torque is applied in the second vehicle V2. The magnitude of the regenerative braking torque can be controlled more accurately than that of the hydraulic braking torque. Therefore, it becomes possible to accurately obtain the point in time when the absolute value of the slip ratio Sij becomes equal to or greater than the set value Sa, and the road surface μ can be obtained accurately.

[0041] Furthermore, although the vehicle V is often in a four-wheel drive state, a driving command (drive state switching command) for switching the second vehicle V2 to a two-wheel drive state can be generated. In the two-wheel drive state, the drive torque applied to the wheels 10 can be made larger than in the four-wheel drive state, so that a slip state can be detected accurately. Also, in the two-wheel drive state, the drive torque applied to the wheels can be obtained more accurately than in the four-wheel drive state, and the road surface μ can be obtained more accurately.

[0042] Also, a driving command (route change command) can be generated to deviate the route of the second vehicle V2 from the route of the first vehicle V1. Although multiple vehicles V often travel along the same predetermined route, the road surface μ of a portion along the route of the first vehicle V1 is acquired by the first vehicle V1, and therefore the road surface μ of a portion different from that portion is acquired. This makes it possible to efficiently acquire the road surface condition within the area.

[0043] The map information creation unit 158 ​​creates and updates map information by adding road surface μ information to a map showing the topography, roads, etc. within an area based on the road surface μ information, vehicle position information, etc. included in the vehicle information. The map information created and updated by the map information creation unit 158 ​​is stored in the map information storage unit 154.

[0044] The work plan storage unit 160 stores work plans for multiple vehicles V that perform work within an area. The work plans store movement plans (movement routes, movement start times, etc.) for each of the multiple vehicles V, cargo (luggage) to be loaded onto each of the multiple vehicles V, and the like. These are often stored based on the identification information of each of the multiple vehicles V.

[0045] In the central control ECU 150, a central control information generating program shown in the flowchart of FIG. 8 is executed at predetermined set time intervals. In S31, it is determined whether or not vehicle information has been received by the central communication device 152. If vehicle information has been received, in S32 and S33, road surface μ information and vehicle position information are acquired from the vehicle information, and in S34, map information is created and updated. Then, the created map information is stored in the map information storage unit 154.

[0046] Next, in S35, it is determined whether the road surface μ is smaller than the set μ value. If the determination is YES, in S36, the identification information (ID1) is acquired, and the vehicle (first vehicle V1) that transmitted the vehicle information is specified. In S37, based on the work plan stored in the work plan storage unit 160, the second vehicle V2 that is the vehicle following the first vehicle V1 is specified, and the identification information ID2 of the second vehicle V2 is acquired. In addition, when identifying the first vehicle V1 and the second vehicle V2, it is desirable to also take into consideration the vehicle position information included in the vehicle information transmitted from the first vehicle V1. In S38, a travel command for the second vehicle V2 is created.

[0047] Then, in S39, central control information including the created travel command, the identification information ID2 of the second vehicle V2, etc. is created, and in S40, this is supplied to the central communication device 152. The central communication device 152 transmits the central control information.

[0048] In each of the plurality of vehicles V, a remote control program serving as a driving control program shown in FIG. 7 is executed by the driving control unit 86 at predetermined set time intervals. In S51, it is determined whether central control information has been received by the vehicle communication device 108, and in S52, it is determined whether the identification information included in the central control information matches the identification information representing the vehicle itself. If the determinations in S51 and S52 are YES, it is determined in S53 whether the driving command included in the central control information is a route change command, in S54 whether it is a drive state switch command, and in S55 whether it is a braking control command.

[0049] If the determination in S53 is YES, in S56, the steering device ST and the like are controlled so that the vehicle V travels along the route in accordance with the route change command. If the determination in S54 is YES, in S57, the transfer 26 and the like are controlled to switch to the two-wheel drive state.

[0050] If the determination in S55 is YES, then in S58 it is determined whether or not wheel position information is included, and in S59 it is determined whether or not a regenerative braking switch command is included. If the determination in S58 is YES, in S60, the hydraulic control actuator 46 is controlled to control the pressing force of the hydraulic brake 40 on the wheel 10 at the position represented by the wheel position information.

[0051] If the determination in S59 is YES, in S61, it is determined whether or not there is a possibility that the absolute value of the slip ratio Sij will be equal to or greater than the set value Sa, taking into consideration the maximum regenerative braking torque that can be output when the hydraulic braking torque is set to 0 (in FIG. 7, this is indicated as lock prediction). If the hydraulic braking torque is set to 0, the braking torque applied to the wheel 10 by the brake device B becomes small, and the braking force between the wheel 10 and the road surface may not reach the maximum friction force. If the determination in S59 is YES, in S62, the hydraulic braking torque is controlled to 0, and only regenerative braking torque is applied.

[0052] For example, when the remote control program is executed in the second vehicle V2, the identification information ID2 included in the central control information matches the identification information representing the second vehicle V2 itself. Therefore, the determination in S52 is YES. By executing S53 and subsequent steps, one or more of the drive and transmission device D, the braking device B, and the steering device ST of the second vehicle V2 are controlled based on the travel command transmitted from the central control device C, thereby controlling the travel state of the second vehicle V2.

[0053] Then, the second vehicle V2 acquires road surface μ information, and creates and transmits vehicle information including the road surface μ information. The central control device C receives the vehicle information transmitted from the second vehicle V2, and acquires the road surface μ information. For example, the road surface μ acquired by the second vehicle V2 is considered to be more accurate than the value acquired by the first vehicle V1. Therefore, map information can be acquired satisfactorily based on the road surface μ acquired by the second vehicle V2. In addition, when the second vehicle V2 acquires the road surface μ condition of a portion different from the portion where the road surface μ was acquired by the first vehicle V1, the map information can be acquired efficiently.

[0054] As described above, in this embodiment, the running state of the second vehicle V2 is controlled based on the road surface state detected by the first vehicle V1, which is the vehicle that transmitted the vehicle information. As a result, the road surface μ acquired by the first vehicle V1 can be corrected to the road surface μ acquired by the second vehicle V2, and the accuracy of the road surface μ can be improved. Since the first vehicle V1 and the second vehicle V2 are the same type and model of vehicles, there is little variation in the characteristics of the vehicles. Therefore, it can be considered that the road surface μ acquired by the first vehicle V1 and the road surface μ acquired by the second vehicle V2 were acquired by the same vehicle, and the accuracy of the acquired road surface μ state can be improved.

[0055] In addition, in order to improve the accuracy of road surface μ information, it is possible for the same vehicle to drive the same route multiple times. In comparison with this case, in this embodiment, road surface μ information can be obtained more accurately and efficiently.

[0056] Furthermore, since the second vehicle V2 obtains road surface μ information for a portion of the road surface that is not obtained by the first vehicle V1, it becomes possible to efficiently obtain road surface μ within the region.

[0057] Furthermore, the central control ECU 150 can create a driving command for at least one of the multiple vehicles V based on the updated map information. For example, when a third vehicle V3 (see FIG. 1) among the multiple vehicles is traveling toward a portion where the road surface μ is smaller than a set μ value, the central control ECU 150 can create a route change command to the third vehicle V3 to change the driving route or a deceleration command to decelerate the vehicle.

[0058] An example of this case is shown in the flow chart of FIG. In S71, map information is read, and in S72, it is determined whether or not there is a vehicle (e.g., the third vehicle V3) among the multiple vehicles V that is traveling toward a portion with a small road surface μ. If the determination is YES, in S73, the identification information ID3 of the third vehicle V3 is acquired, and in S74, a travel command for the third vehicle V3 is created. In S75, central control information including the identification information ID3 of the third vehicle V3 and the travel command is created, and in S76, the central control information is supplied to the central communication device 152.

[0059] In this embodiment, map information is acquired with high accuracy, so that appropriate driving commands can be provided to the multiple vehicles V. The driving performance of each of the multiple vehicles V can be improved, and the vehicles V are less likely to get stuck. As a result, the work efficiency can be improved.

[0060] As described above, in this embodiment, the part that stores S31 to S34 of the central control information creation program of the central control ECU 150, the part that executes S31 to S34, and the like constitute an in-area road surface condition acquisition unit and a map information creation unit. Also, the road surface condition acquisition unit 84 is a road surface μ etc. related condition acquisition unit and a road surface μ acquisition unit. Note that the central control ECU 150, the central communication device 152, and the like constitute a management system. Also, the identification information, the vehicle position information, and the like are examples of moving body position identification information.

[0061] In the above embodiment, the vehicle V is in an automatic driving state, but the present invention can also be implemented when the vehicle V is in a manual driving state. In this embodiment, a driving command as a travel command is generated and transmitted in the central control device C. In each of the multiple vehicles V, the driving command is notified to the driver via the notification device 106. When the vehicle V is a manually operated vehicle or a vehicle that can be switched between a manual driving state and an automatic driving state, a steering operation member, a brake operation member, a drive state changeover switch that can be switched between a four-wheel drive state and a two-wheel drive state, and the like are usually provided. Therefore, as driving commands, a command to operate the steering operation member, a command to ease the operation state of the brake operation member, a command to operate the drive state changeover switch, and the like are generated and transmitted. The driver drives the vehicle V in accordance with the driving command supplied via the notification device 106.

[0062] In addition, for example, it is also possible to perform driving assistance such as providing operation assistance to encourage operation of a steering operation member in one direction based on a driving command (for example, applying a force in one direction to the steering operation member).

[0063] In addition, the vehicle information can include slip ratio information that indicates the slip ratio of the wheel 10. This allows the central control device C to clearly acquire information that the slip ratio of the wheel 10 has increased and that the road surface μ has changed from a low state to a high state. For example, if a torque greater than the torque applied by the drive / transmission device D or the braking device B when the slip ratio was last greater than the set value Sa is applied to the wheel 10, and the slip ratio is smaller than the set value Sa, it can be estimated that the road surface μ has changed to a higher one.

[0064] Further, the road surface μ related condition can be acquired based on the detection value of the yaw rate sensor 92. One example of this is shown in the flowchart of FIG. In S91, the actual yaw rate, which is the detection value of the yaw rate sensor 92, is read, and in S92, the steering angle of the steering device ST (the rotation angle of the steering actuator 60) and the traveling speed vs of the vehicle V are acquired, and the target yaw rate γa is acquired based on these. Then, in S93, it is determined whether the actual yaw rate γ is within a set range determined by the target yaw rate γa. If the determination is YES, in S94, it is determined that the road surface μ is in a high state, and if the determination is NO, in S95, it is determined that the road surface μ is in a low state.

[0065] In this manner, in the present embodiment, vehicle information including road surface μ-related information indicating whether the road surface μ is in a low or high state is transmitted, so that the central control device C can easily obtain whether the road surface μ is in a low or high state.

[0066] In the above embodiment, the vehicles V are hybrid vehicles, but the present invention is not limited to this. For example, the vehicles V may be electric vehicles as shown in FIG. The vehicle shown in Fig. 11 includes an electric motor 172F for driving a front wheel and an electric motor 172R for driving a rear wheel. On the front wheel side, the electric motor 172F is connected to a differential device 178F via a transmission 176F, and the differential device 178F is connected to drive shafts 24FL, 24FR, respectively, and is connected to the left and right front wheels 10FL, 10FR. The same is true for the rear wheel side. The differential device 178 may include, for example, a differential gear mechanism.

[0067] Further, the electric motors 172F, 172R are connected to a common battery 184 via inverters 182F, 182R, respectively. By controlling the inverters 182F, 182R, a state is switched between one in which power from the battery 184 is supplied to the electric motor 172 and one in which power generated in the electric motor 172 is charged into the battery 184 to generate a regenerative braking force. In other words, the output of the electric motor 172 or the regenerative braking force is applied to the wheels 10 via the transmission 176, the differential device 178, and the drive shaft, respectively.

[0068] In this embodiment, the vehicle is in a four-wheel drive state when the electric motors 172F, 172R are in a driving state, and in a two-wheel drive state when either one of the electric motors 172F, 172R is in a free state.

[0069] The vehicle V may be any of a vehicle whose drive source does not include an electric motor, an electric vehicle whose drive source does not include an engine, a fuel cell vehicle, etc. Also, an in-wheel motor may be provided on each wheel 10 as a drive source. Furthermore, each of the steered wheels 10 may be provided with a steering device capable of independently steering. Also, the structure of the vehicle V is not limited, and may include an electric brake as a friction braking device.

[0070] Furthermore, in the above embodiment, the road surface μ and road surface μ related conditions are acquired as the road surface conditions, but it is also possible to acquire the road surface unevenness condition as the road surface conditions.

[0071] In addition, the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0072] 10: Wheel 11: Engine 12: Electric motor 26: Transfer 36: Inverter 38: Battery 40: Hydraulic brake 41: Hydraulic braking device 46: Hydraulic control actuator 60: Steering actuator 80: Vehicle ECU 82: Identification information storage unit 84: Road surface condition acquisition unit 86: Travel control unit 88: Vehicle information creation unit 90: Wheel speed sensor 108: Vehicle communication device 150: Central control ECU 152: Central communication device 154: Map information storage unit 156: Travel command creation unit 158: Map information update unit B: Braking device D: Drive and transmission device ST: Steering device Patentable invention

[0073] The following paragraphs set forth inventions which may be claimed. (1) A road surface condition acquisition system including a central control device that acquires a road surface condition, which is a condition of a road surface within an area in which a plurality of moving bodies move, by communicating with each of the plurality of moving bodies, Each of the plurality of moving bodies is (i) a moving body road surface condition acquisition unit for acquiring a road surface condition on a road surface on which the moving body is moving; (ii) a mobile communication device that transmits mobile information including mobile road surface condition information that is information representing the road surface condition acquired by the mobile road surface condition acquisition unit; The central control device, (a) a central communication device for receiving the mobile unit information; (b) a movement command generation unit that generates a movement command, which is a command regarding the movement of at least one of the plurality of moving objects, based on the moving object information received by the central communication device; the central communication device transmits central control information including the movement command created by the movement command creation unit, The central control device includes an area road surface condition acquisition unit that acquires road surface conditions within the area based on the mobile object information received by the central communication device.

[0074] The road surface condition can be, for example, the unevenness of the road surface, or a road surface μ-related condition related to the road surface μ, etc. The road surface μ-related condition can be expressed by the road surface μ, or whether the road surface μ is small or large (whether the road is a low μ road or a high μ road), etc.

[0075] When the moving body is in an automatic driving state and can be remotely controlled based on a command from a central control device, the movement command can represent a command for the running state of the moving body (including commands to the drive device, braking device, and steering device).When the moving body is in a manual driving state and cannot be remotely controlled, the movement command can represent a driving (operation) command to the driver.

[0076] The mobile communication device may transmit mobile information at set time intervals while traveling, or may transmit mobile information when the unevenness of the road surface is equal to or greater than a set state, when the friction coefficient of the road surface is obtained, etc.

[0077] The area in which the multiple mobile bodies move can be, for example, an area in which the multiple mobile bodies perform work. In the case where the multiple mobile bodies perform work in a mine, the area refers to the work area of ​​the mine.

[0078] (2) The moving object information includes moving object position specifying information that is information that can specify a position where the moving object is moving, The in-area road surface condition acquisition unit, a map information creation unit that creates map information representing road surface conditions within the area based on the moving object road surface condition information and the moving object position identification information included in the moving object information received by the central communication device; A road surface condition acquisition system according to claim 1, further comprising a map information storage unit configured to store the map information created by the map information creation unit.

[0079] The mobile object position specifying information may be information representing the position of the mobile object, i.e., the two-dimensional position (latitude, longitude) where the mobile object is located, information representing the three-dimensional position (latitude, longitude, altitude), or identification information capable of specifying the position of the mobile object, etc. For example, when the central control device stores movement plan information (movement route, movement time, etc.) of each of a plurality of mobile objects, the position of the mobile object can be determined by knowing the identification information that specifies the mobile object.

[0080] (3) The moving body road surface condition acquisition unit includes a road surface μ etc. related condition acquisition unit that acquires a road surface μ, which is a friction coefficient of the road surface, or a condition related to the road surface μ as a condition of the road surface on which the moving body moves, A road surface condition acquisition system as described in (1) or (2), wherein the mobile body road surface condition information includes road surface μ-related information, which is information representing the road surface μ or information representing a condition related to the road surface μ.

[0081] The slipperiness of the road surface can be known based on the road surface μ. The state related to the road surface μ includes a state in which the road surface μ is low, a state in which the road surface μ is high, and the like.

[0082] (4) Each of the plurality of moving bodies includes a plurality of wheel speed sensors that detect the rotation speed of each of a plurality of wheels provided on the moving body, an acceleration sensor that detects the acceleration of the moving body, and a yaw rate sensor that detects the yaw rate of the moving body, The road surface condition acquisition system described in (3) above, wherein the road surface μ etc. related condition acquisition unit acquires the road surface μ or a condition related to the road surface μ based on at least one or more of the multiple detection values ​​of the multiple wheel speed sensors, the detection value of the acceleration sensor, and the detection value of the yaw rate sensor.

[0083] For example, if the detection value of the yaw rate sensor is outside a set range determined by a target yaw rate determined based on the steering angle and the travel speed, it can be determined that the road surface μ is in a low state (road surface μ related state).

[0084] The road surface μ etc. related conditions include road surface μ and road surface μ related conditions, and the road surface μ etc. related information includes road surface μ information and road surface μ related information.

[0085] (5) A road surface condition acquisition system as described in (4), including a road surface μ acquisition unit that acquires the road surface μ with which at least one of the plurality of wheels is in contact when the road surface μ etc. related condition acquisition unit detects that the slip state of the at least one of the plurality of wheels has reached or exceeded a set state based on the detection values ​​of the plurality of wheel speed sensors.

[0086] When the slip state exceeds the set state, it can be considered that the longitudinal force (driving force or braking force) acting between the wheel and the road surface has reached the maximum friction force. Therefore, in this case, the longitudinal force (maximum friction force) acting between the wheel and the road surface is obtained based on the driving torque or braking torque applied to the wheel from the vehicle's driving / transmission device or braking device, and the road surface μ is obtained based on this maximum friction force and the load acting on the wheel.

[0087] (6) each of the plurality of moving bodies includes a storage unit configured to store a weight of a load loaded on the moving body; A road surface condition acquisition system described in any one of items (5), wherein the road surface μ acquisition unit acquires the road surface μ using a moving body weight acquired based on the weight of the load stored in the memory unit.

[0088] Each moving object is managed by its identification information. The driver and the load are stored in association with the identification information of the moving object, and the weight of the entire moving object is obtained based on these. In addition, if the load and the position of the driver are known, the load applied to each wheel can also be determined. The storage unit described in this section corresponds to the identification information storage unit in the above embodiment.

[0089] In addition, when the load weight, driver weight, and their positions, etc. are stored in a central control device, information on the load weight, etc. can be obtained from multiple moving bodies through communication between the central control device and multiple moving bodies, and road surface μ can be obtained.

[0090] (7) The moving object information includes identification information for identifying each of the plurality of moving objects, the central control device includes a movement plan information storage unit that stores movement plan information that is information regarding a movement plan of each of the plurality of moving objects; A road surface condition acquisition system as described in any one of (1) to (6), wherein the movement command creation unit identifies a first moving body which is a moving body that transmitted the moving body information among the plurality of moving bodies based on the identification information and the movement plan information contained in the moving body information received by the central communication device, and identifies a second moving body which is a moving body following the first moving body, and creates a command regarding the movement of the second moving body.

[0091] The central control device stores data on a movement plan (work plan) that indicates the planned movement routes of the multiple moving bodies, etc. Therefore, based on the work plans of the multiple moving bodies and the identification information of the first moving body, it is possible to specify the identification information of the second moving body that is a moving body following the first moving body.

[0092] (8) The road surface condition acquisition system according to (7), wherein the movement command creation unit creates a command for the second moving body to travel a different route from that of the first moving body.

[0093] A movement command is generated to change the path of the second moving body from the path of the first moving body in order to obtain the road surface condition of a portion of the road surface different from the portion in contact with the wheels of the first moving body. The moving body road surface condition acquisition unit of the second moving body acquires the road surface condition of the portion of the road surface different from that of the first moving body.

[0094] (9) The moving body road surface condition acquisition unit includes a road surface μ acquisition unit that acquires a friction coefficient μ of the road surface as a condition of the road surface on which the moving body moves, The moving object road surface condition information includes information representing the road surface μ, Each of the plurality of moving bodies includes a drive / transmission device that is switchable between a four-wheel drive state and a two-wheel drive state, The road surface condition acquisition system described in (7) or (8), wherein the movement command creation unit creates a command to the second moving body to switch from the four-wheel drive state to the two-wheel drive state when the road surface μ represented by the road surface μ information included in the moving body information transmitted from the first moving body and received by the central communication device is smaller than a set μ value.

[0095] By setting the vehicle in two-wheel drive mode, it is possible to obtain the driving force, which is the longitudinal force applied to the wheels, with high accuracy, and it is also possible to obtain the friction coefficient of the road surface with high accuracy.

[0096] (10) Each of the plurality of moving bodies includes a plurality of wheel speed sensors that detect the rotation speeds of a plurality of wheels provided on the moving body, the moving object road surface condition acquisition unit includes a road surface μ acquisition unit that acquires a friction coefficient of a road surface with which the at least one wheel is in contact when it is detected that a slip state of at least one wheel among the plurality of wheels has reached or exceeded a set state based on detection values ​​of the plurality of wheel speed sensors; The moving object road surface condition information includes information representing the road surface μ, the moving object information includes wheel position information representing a position of the at least one wheel among the plurality of wheels in which the slip state has been set, A road surface condition acquisition system as described in any one of items (7) to (9), wherein the movement command creation unit creates a command to reduce the torque applied by the second moving body to the wheel of the second moving body at a position determined by the wheel position information.

[0097] The torque may be a driving torque or a braking torque. However, if the driving torque cannot be controlled for each wheel, the technical feature according to this section is applied when the road surface μ is obtained in a state where the braking torque is applied. Moreover, the torque applied to the wheel by the second moving body refers to the torque applied to the wheel by the drive / transmission device and braking device included in the second moving body.

[0098] (11) Each of the plurality of moving bodies includes a friction braking device that applies a friction braking torque to each of the plurality of wheels, and a regenerative braking device that applies a regenerative braking torque to a driving wheel of the plurality of wheels, the moving body road surface condition acquisition unit includes a road surface μ acquisition unit that acquires a friction coefficient μ of the road surface as a state of the road surface on which the moving body moves, The road surface condition acquisition system described in any one of items (7) to (10), wherein the movement command creation unit creates a command to the second moving body to apply the regenerative braking torque to the drive wheels and not apply the frictional braking torque when the road surface μ represented by the road surface μ information included in the moving body information transmitted from the first moving body received by the central communication device is smaller than a set μ value.

[0099] (12) The road surface condition acquisition system described in (3) is configured so that the road surface μ etc. related condition acquisition unit acquires that the road surface is a high μ road when the torque applied to the wheel is equal to or greater than the torque applied to the wheel the previous time the road surface μ was acquired, and when the slip condition of the at least one wheel is smaller than a set condition.

[0100] For example, a change in the coefficient of friction of the road surface from low to high can be effectively reported to the central control device.

[0101] (13) A road surface condition acquisition system as described in any one of (1) to (12), wherein each of the plurality of moving bodies is in an automatic driving state in which the driving state can be controlled based on commands from the central control device, and the driving state of the moving bodies can be remotely controlled based on commands from the central control device.

[0102] (14) A road surface condition acquisition system as described in (2), wherein the movement command creation unit creates a movement command for at least one of the plurality of moving bodies based on the map information stored in the map information storage unit.

[0103] For example, if the road surface μ at the position P indicated by the map information is low, a command can be created for a moving body that is scheduled to travel through that position P to avoid that position P or to reduce its speed.

[0104] (15) A management system including a central control device that manages a plurality of mobile objects through communication with the plurality of mobile objects, Each of the plurality of moving bodies is (i) a road surface condition acquisition unit that acquires a road surface condition on which the moving object is traveling; (ii) a mobile communication device for transmitting mobile object information including at least road surface condition information, which is information representing the condition of the road surface acquired by the road surface condition acquisition unit, and mobile object position information, which is information regarding a position where the mobile object is traveling; The central control device, (a) a central communication device for receiving the mobile unit information; (b) a map information update unit that updates map information based on the moving object information received by the central communication device; (c) a map information storage unit that stores the map information updated by the map information update unit; and generating a movement command for at least one of the plurality of moving objects based on the map information stored in the map information storage unit. The management system described in this section may employ any of the technical features described in sections (1) to (13).

Claims

1. By communicating with each of a plurality of moving bodies, the state of the road surface within the area in which the plurality of moving bodies move is A road surface condition acquisition system including a central control device that acquires a road surface condition, Each of the plurality of moving bodies is in an automatic driving state in which the traveling state of the moving body can be remotely controlled based on a command from the central control device, and (i) a plurality of wheel speed sensors each detecting a rotation speed of a plurality of wheels provided on the moving object; (ii) a mobile body road surface condition acquisition unit that, when it is detected based on the detection values ​​of the wheel speed sensors that the slip state of at least one of the plurality of wheels has reached a set state or greater, acquires a friction coefficient of a road surface with which the at least one wheel is in contact as a road surface condition of the road surface on which the mobile body is moving; (iii) a mobile communication device that transmits mobile information including at least road surface μ information, which is information representing a friction coefficient of the road surface acquired by the mobile road surface condition acquisition unit, wheel position information representing a position of the at least one wheel where the slip state has reached a set state or more, and identification information for identifying the mobile communication device itself; The central control device, (a) a central communication device for receiving the mobile unit information; (b) a movement command generation unit that generates a movement command, which is a command regarding the movement of at least one of the plurality of moving objects, based on the moving object information received by the central communication device; The central communication device transmits a central communication signal including the movement command generated by the movement command generating unit. It transmits air traffic control information, The central control device may perform a pre-selection based on the mobile information received by the central communication device. a region road surface condition acquisition unit that acquires a road surface condition within the region; and a movement plan information storage unit that stores movement plan information that is information regarding a movement plan of each of the plurality of moving bodies, A road surface condition acquisition system in which the movement command creation unit identifies a first moving body among the multiple moving bodies, which is the moving body that sent the moving body information, and identifies a second moving body which is the moving body following the first moving body, based on the identification information and the movement plan information contained in the moving body information received by the central communication device, and creates a command to make the torque applied by the second moving body to the wheel of the second moving body at a position determined by the wheel position information less than the torque applied by the first moving body.

2. Each of the plurality of moving bodies includes a friction braking device that applies a friction braking torque to each of the plurality of wheels, and a regenerative braking device that applies a regenerative braking torque to a driving wheel of the plurality of wheels, When the road surface μ represented by the road surface μ information included in the moving body information transmitted from the first moving body and received by the central communication device is smaller than a set μ value, the movement command creation unit applies the regenerative braking torque to the driving wheels of the second moving body and applies the friction braking torque. The road surface condition acquisition system according to claim 1, further comprising a command for generating a command for causing the road surface condition acquisition system to generate ...

3. Each of the plurality of moving bodies includes a drive / transmission device that can be switched between a four-wheel drive state and a two-wheel drive state; The road surface condition acquisition system of claim 1 or 2, wherein the movement command creation unit creates a command for the second moving body to switch from the four-wheel drive state to the two-wheel drive state when the road surface μ represented by the road surface μ information included in the moving body information transmitted from the first moving body received by the central communication device is smaller than a set μ value.

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