Vehicle control device

Abstract

To suppress shortening of inter-vehicular distance between convoy travel vehicles when traveling in inertia during the convoy travel.SOLUTION: When performing a convoy travel, information on an estimated value of deceleration is acquired for each vehicle participating in the convoy travel on the basis of driven torque applicable to an individual inertia travel in a present vehicle state, and driven torque is controlled for each of the vehicles participating in the convoy travel so as to line up, from the top, the convoy travel participating vehicle in sequence of ascending order of the estimated value of deceleration, and therefore, it is possible to suppress actual deceleration of a preceding vehicle from being decreased even if an air resistance of a following vehicle is made smaller than of the preceding vehicle. It is therefore possible to suppress shortening of inter-vehicular distance between the convoy travel participating vehicles when traveling in inertia during the convoy travel.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a vehicle control device that controls platooning of vehicles participating in a platoon, including a leading vehicle and following vehicles. [Background technology]

[0002] There is a well-known vehicle control device that connects each of the platoon participating vehicles, including a leading vehicle and a following vehicle that automatically follows the leading vehicle in a single file at a predetermined distance from the leading vehicle, via wireless communication and controls the platoon traveling of the platoon participating vehicles. One example is the platoon traveling control device described in Patent Document 1. Patent Document 1 discloses that the vehicles to be included in the platoon are determined based on a travel plan for controlling the vehicle speed to a target vehicle speed by alternately repeating accelerating travel and decelerating travel or coasting travel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-43444 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when driving in a convoy to maintain vehicle speed, for example when the required drive torque is set to zero and the vehicle decelerates naturally, i.e. when coasting, there is a risk that the distance between the vehicles in the convoy will become shorter due to differences in the running resistance of each vehicle.

[0005] The present invention has been made against the background of the above circumstances, and its purpose is to provide a vehicle control device that can prevent the inter-vehicle distance between vehicles participating in a platoon from becoming shorter when they are coasting during platooning. [Means for solving the problem]

[0006] The gist of a first invention is a vehicle control device that (a) connects via wireless communication each of platoon participating vehicles including a lead vehicle and a follow vehicle that automatically follows the lead vehicle in single file at a predetermined vehicle distance, and controls platooning by the platoon participating vehicles, and (b) while the platooning is being performed, obtains information on an estimated value of deceleration based on a driven torque when the platoon participating vehicles coast independently in a current vehicle state for each of the platoon participating vehicles, and controls the driven torque of each of the platoon participating vehicles so that the platoon participating vehicles are arranged in order of increasing estimated deceleration value starting from the lead vehicle. (c) in the platoon participating vehicle equipped with a rotary machine as a power source, the driven torque obtained by regenerative braking due to the regenerative operation of the rotary machine is controlled by changing the regeneration amount of the rotary machine. The point is...

[0007] Also, the second invention The gist of the present invention is that (a) a vehicle control device that connects each of the platoon participating vehicles, including a lead vehicle and a follower vehicle that automatically follows the lead vehicle in a single file at a predetermined vehicle distance from the lead vehicle, via wireless communication and controls the platooning of the platoon participating vehicles, (b) while the platooning is being performed, obtains information on an estimated value of deceleration based on a driven torque when the platoon participating vehicles coast independently in a current vehicle state for each of the platoon participating vehicles, and controls the driven torque of each of the platoon participating vehicles so that the platoon participating vehicles are arranged in order of increasing estimated deceleration value starting from the lead vehicle, and (c) In a vehicle participating in a platoon that is equipped with an engine as a power source and an automatic transmission that transmits the power of the engine to the drive wheels, the driven torque obtained by engine braking due to friction of the engine is controlled by changing the gear ratio of the automatic transmission.

[0008] The third invention is the above Record number In the vehicle control device described in the invention of 2, in the platooning vehicle equipped with a rotating machine as a power source, the driven torque obtained by regenerative braking due to the regenerative operation of the rotating machine is controlled by changing the amount of regeneration of the rotating machine.

[0009] In addition, a fourth invention is a vehicle control device described in any one of the first to third inventions, which obtains information on an estimated value of the deceleration that takes into account differences in air resistance due to the order of the vehicles joining the platoon.

[0010] In addition, a fifth invention is a vehicle control device described in any one of the first to fourth inventions, in which an estimated value of the deceleration based on the driven torque of each vehicle participating in the platoon is calculated before the platoon driving is performed.

[0011] In addition, a sixth invention is a vehicle control device described in any one of the first to fifth inventions, in which an estimated value of the deceleration based on the driven torque of each vehicle participating in the platoon is calculated based on vehicle weight.

[0012] In addition, a seventh invention is a vehicle control device described in any one of the first to sixth inventions, which terminates control of the driven torque when the inter-vehicle distance between any of the platoon-participating vehicles exceeds a predetermined termination judgment threshold value that is longer than the predetermined inter-vehicle distance due to control of the driven torque. Effect of the Invention

[0013] According to the first aspect of the present invention, while platooning is being performed, information on an estimated value of deceleration based on the driven torque when the vehicle is coasting alone in the current vehicle state is obtained for each vehicle participating in the platoon, and the driven torque of each vehicle participating in the platoon is controlled so that the vehicles are arranged in an order in which the estimated value of deceleration increases from the leading vehicle, so that the actual deceleration is prevented from becoming smaller even if the air resistance of the following vehicle is reduced relative to the leading vehicle. Therefore, it is possible to prevent the inter-vehicle distance between the vehicles participating in the platoon from becoming shorter when coasting during platooning. In addition, according to the first invention, in a platooning vehicle equipped with a rotating machine, the driven torque obtained by regenerative braking due to the regenerative operation of the rotating machine is controlled by changing the amount of regeneration of the rotating machine, making it easier to control the driven torque so that the vehicles participating in the platoon are arranged in an order such that the estimated deceleration value increases from the leading vehicle.

[0014] According to the second aspect of the present invention, while platooning is being performed, information on an estimated value of deceleration based on the driven torque when the vehicle is coasting alone in the current vehicle state is obtained for each vehicle participating in the platoon, and the driven torque of each vehicle participating in the platoon is controlled so that the vehicles are arranged in an order in which the estimated value of deceleration increases from the leading vehicle, so that the actual deceleration is prevented from becoming smaller even if the air resistance of the following vehicle is reduced relative to the leading vehicle. Therefore, it is possible to prevent the inter-vehicle distance between the vehicles participating in the platoon from becoming shorter when coasting during platooning. In addition, according to the second invention, in a platooning vehicle equipped with an engine and an automatic transmission, the driven torque obtained by engine braking due to engine friction is controlled by changing the gear ratio of the automatic transmission, making it easier to control the driven torque so that the vehicles in the platoon are arranged in an order such that the estimated deceleration value increases from the leading vehicle.

[0015] In addition, according to the third invention, in a platooning vehicle equipped with a rotating machine, the driven torque obtained by regenerative braking due to the regenerative operation of the rotating machine is controlled by changing the amount of regeneration of the rotating machine, making it easier to control the driven torque so that the vehicles participating in the platoon are arranged in an order such that the estimated deceleration value increases from the leading vehicle.

[0016] In addition, according to the fourth invention, information on an estimated deceleration value is obtained that takes into account differences in air resistance due to the order of the vehicles joining the platoon, thereby further suppressing or avoiding the actual deceleration being smaller even if the air resistance of the following vehicle is smaller than that of the leading vehicle.

[0017] According to the fifth aspect of the present invention, an estimated value of deceleration based on the driven torque of each vehicle participating in the platoon is calculated before the vehicle platoon travels, so that the vehicle platoon can be formed in consideration of the range in which the driven torque can be changed when the vehicle platoon travels. This makes it easier to control the driven torque so that the vehicles participating in the platoon are arranged in the order of increasing deceleration estimated value starting from the leading vehicle.

[0018] In addition, according to the sixth aspect of the present invention, an estimated value of the deceleration based on the driven torque of each vehicle participating in the platoon is calculated based on the vehicle weight, so that an estimated value of the deceleration of each vehicle participating in the platoon is appropriately calculated in accordance with the weight of the occupants.

[0019] In addition, according to the seventh invention, when the control of the driven torque causes the inter-vehicle distance between any of the platoon participating vehicles to exceed a predetermined termination judgment threshold that is longer than the predetermined inter-vehicle distance, the control of the driven torque is terminated, so that if a situation is created in which the inter-vehicle distance between the platoon participating vehicles can be avoided from becoming shorter, the inter-vehicle distance is prevented from becoming longer than that. [Brief description of the drawings]

[0020] [Figure 1] 1 is a schematic diagram illustrating a basic configuration of a platooning system according to an embodiment of the present invention. [Diagram 2]FIG. 2 is a diagram illustrating an example of a vehicle that can be used as a platoon participant vehicle in FIG. 1, and shows a schematic diagram of a drive system as well as control functions for various controls and a main part of the control system. [Diagram 3] FIG. 3 is a schematic diagram for explaining a specific example of the HEV transmission device of FIG. 2. [Figure 4] 4 is an engagement operation table showing the relationship between a plurality of gear stages of a transmission section provided in the HEV transmission device of FIG. 3 and the control states of engagement devices for establishing those gear stages. [Diagram 5] 4 is a diagram illustrating an example of a shift map used in shift control of the shifting section in FIG. 3. [Figure 6] FIG. 13 is a diagram showing an example of deceleration settings in preparation for coasting during platooning. [Figure 7] This is a flowchart explaining the main control operations of a vehicle control device, and is a flowchart explaining the control operations for preventing the inter-vehicle distance between platooning vehicles from becoming shorter when coasting during platooning. [Figure 8] FIG. 13 is a diagram showing an example of deceleration setting that takes air resistance into consideration when coasting during platooning. [Figure 9] This is a flowchart explaining the main control operations of a vehicle control device, and is a flowchart explaining the control operations for preventing the inter-vehicle distance between platooning vehicles from becoming shorter when coasting during platooning, and is a different embodiment from the flowchart of Figure 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] In an embodiment of the present invention, the platooning participating vehicles are various types of vehicles that have been used conventionally, such as engine-driven vehicles, electric vehicles, or hybrid electric vehicles equipped with an engine and a rotating machine as a power source. The engine is an internal combustion engine, such as a gasoline engine or a diesel engine. The engine can provide engine braking by engine friction, for example, when coasting. The rotating machine is, for example, a motor generator that can be selectively used as an electric motor and a generator. The motor generator functions as a power source when used as an electric motor, and can provide regenerative braking when used as a generator. The rotating machine may be, for example, an electric motor that does not provide the function of a generator.

[0022] In addition, a fluid-type transmission device such as a torque converter is provided in the power transmission path between the power source and the automatic transmission as necessary. The fluid-type transmission device may be omitted depending on the power source. For example, an electric differential unit having a planetary gear device and a differential control rotating machine, a friction engagement type starting clutch, or the like may be provided in the power transmission path between the power source and the automatic transmission. The automatic transmission is, for example, a stepped transmission such as a planetary gear type or a two-shaft meshing type, but may also be a continuously variable transmission such as a belt type in which the gear ratio is controlled in stages like a stepped transmission.

[0023] The vehicle control device is a control device used in a vehicle. That is, the vehicle control device can be incorporated in whole or in part into a server installed in, for example, the head office or business office of a transportation company or the like that manages the platooning participating vehicles, or in any other arbitrary location. The vehicle control device can be incorporated in whole or in part into the platooning participating vehicles, and some control functions such as a shift control for shifting the automatic transmission can be incorporated into an on-board control device. The platooning participating vehicles are configured, for example, with one leading vehicle and multiple following vehicles. The platooning participating vehicles may be configured, for example, with one leading vehicle and one following vehicle, for a total of two vehicles. The platooning participating vehicles can travel in a manned manner with a driver on board, or in an unmanned manner with no driver on board, using an automatic steering system or the like that can travel according to a predetermined travel route. The control of the platoon driving by the vehicle control device may be performed via wireless communication between the server and each of the platoon participating vehicles, or via wireless communication between the platoon participating vehicles, such as vehicle-to-vehicle communication.

[0024] The following vehicle has a function of following the preceding vehicle at a predetermined vehicle distance. That is, the vehicle control device calculates a driving demand amount required for following the preceding vehicle so that the vehicle distance between the following vehicle and the preceding vehicle is maintained at a predetermined target vehicle distance, and controls the output of a power source so as to obtain the driving demand amount, thereby executing a following driving control for following the preceding vehicle at the target vehicle distance. In addition to the following driving control, it is desirable that the leading vehicle can execute an autonomous driving control for running at a predetermined target vehicle speed by calculating a driving demand amount required for running at a predetermined target vehicle speed and controlling the output of a power source so as to obtain the driving demand amount. The autonomous driving control may be a constant speed driving control for running at a constant target vehicle speed, or an autonomous driving control for running while changing the vehicle speed according to a target vehicle speed that is sequentially variably set according to a travel route. The following vehicle may also be capable of executing the autonomous driving control in the same manner as the leading vehicle. That is, it is desirable to configure the leading vehicle and the following vehicle to be able to join the platoon at any time as the leading vehicle or the following vehicle. The power source output control in the following running control and the autonomous running control is preferably controlled including negative torque by engine braking, regenerative control of the rotary machine, etc., and braking force control can also be performed via an automatic brake system. The leading vehicle may run by controlling the output of the power source according to the driver's acceleration / deceleration operation. The automatic transmission shift of the leading vehicle is also managed by the vehicle control device, but a leading vehicle or the like that shifts the automatic transmission according to manual operation may be provided in front of the leading vehicle.

[0025] The platooning vehicles may be a mixture of multiple types of vehicles equipped with the automatic transmission having different numbers of gear stages, or may be composed of only vehicles equipped with one type of automatic transmission having the same number of gear stages. The platooning vehicles do not necessarily need to be set with gear shift timing for platooning when traveling in a platoon, and the gear shift timing used when traveling alone may be used as is when traveling in a platoon.

[0026] Moreover, the gear ratio of the automatic transmission is "rotation speed of the input rotating member / rotation speed of the output rotating member." The high-side gear ratio of the automatic transmission is the high vehicle speed side gear ratio where the gear ratio is small. The low-side gear ratio of the automatic transmission is the low vehicle speed side gear ratio where the gear ratio is large. For example, the lowest-side gear ratio is the lowest vehicle speed side gear ratio where the gear ratio is the lowest, and is the maximum gear ratio where the gear ratio is the largest.

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. EXAMPLES

[0028] FIG. 1 is a schematic diagram illustrating a basic configuration of a platooning system 10 according to an embodiment of the present invention. In FIG. 1, the platooning system 10 includes platooning participating vehicles 12 and a server 20 serving as a platoon management center. Such platooning is performed mainly on roads for automobiles, such as expressways. The platooning participating vehicles 12 include a plurality of platooning participating vehicles 12le, 12fo-1, 12fo-2, . . . 12fo-n. The platooning participating vehicle 12le is the leading vehicle in the platoon. The platooning participating vehicles 12fo-1, 12fo-2, . . . 12fo-n are following vehicles that automatically follow the leading vehicle 12le in a single file at a predetermined inter-vehicle distance, and are numbered 12fo-1, 12fo-2, . . . 12fo-n in order from the leading vehicle. In this embodiment, unless otherwise specified, the following vehicles 12fo-1, 12fo-2, ..., 12fo-n are referred to as following vehicles 12fo, and the leading vehicle 12le and the following vehicles 12fo are referred to as platoon participating vehicles 12. The server 20 is, for example, an electronic control device such as a personal computer. The server 20 may be provided, for example, in the head office or sales office of the company to which the platoon participating vehicles 12 belong, or a commercial facility may be used.

[0029] FIG. 2 is a diagram for explaining an example of a vehicle 30 that can join the platoon as the platoon participating vehicle 12 in FIG. 1, and shows a schematic diagram of the drive system as well as the main parts of the control functions and control system for various controls. In FIG. 2, the vehicle 30 is a normal vehicle that can run alone as well as in a platoon, and is equipped with an on-board control device 130 that is an on-board electronic control device. When the vehicle 30 joins the platoon as the platoon participating vehicle 12, the on-board control device 130 of each platoon participating vehicle 12 and the server 20 are connected via a wireless communication R network such as a mobile phone network, a wireless LAN network, or the Internet (see FIG. 1), and various information can be transmitted and received. Alternatively, when the vehicle 30 joins the platoon as the platoon participating vehicle 12, the platoon participating vehicles 12 may be connected via wireless communication between each other, such as vehicle-to-vehicle communication.

[0030] Both the on-board control device 130 and the server 20 include a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc., and the CPU can execute various controls by performing various signal processing according to programs previously stored in the ROM while utilizing the temporary storage function of the RAM. The on-board control device 130 and the server 20 are a vehicle control device 150 that connects each of the platoon participating vehicles 12 via wireless communication R and controls the platoon traveling of the platoon participating vehicles 12.

[0031] The vehicle 30 is a front-to-rear wheel drive, i.e., four-wheel drive, hybrid electric vehicle based on a front-mounted engine, rear-wheel drive system (=FR system). The vehicle 30 includes an engine 32, a hybrid electric vehicle (HEV) transmission device 34 connected to the engine 32, and a transfer 36 connected to the HEV transmission device 34. A front propeller shaft 38 and a rear propeller shaft 46 are respectively connected to the transfer 36. Power transmitted from the engine 32 and the HEV transmission device 34 to the transfer 36 is distributed to the front propeller shaft 38 and the rear propeller shaft 46 via the transfer 36. The power distributed to the front propeller shaft 38 is transmitted to left and right front wheels 44 via a front wheel differential gear 40 and left and right front wheel drive shafts 42. The power distributed to the rear propeller shaft 46 is transmitted to left and right rear wheels 52 via a rear wheel differential gear 48 and left and right rear wheel drive shafts 50. The rear wheels 52 are main drive wheels that serve as drive wheels DW in both two-wheel drive (=2WD) and four-wheel drive (=4WD) driving. The front wheels 44 are auxiliary drive wheels that serve as driven wheels in 2WD driving and as drive wheels DW in 4WD driving.

[0032] The engine 32 is an internal combustion engine such as a gasoline engine or a diesel engine, and is used as a power source SP for traveling. The engine 32 controls an engine torque Te, which is an output torque of the engine 32, by controlling an engine control device (not shown) having a throttle actuator, a fuel injection device, an ignition device, etc., by the on-board control device 130. In addition, the engine 32 can generate engine brakes by friction when it is rotationally driven by power input from the drive wheels DW side during coasting, for example.

[0033] Fig. 3 is a schematic diagram for explaining a specific example of the HEV transmission 34. In Fig. 3, the HEV transmission 34 includes a rotating machine MG disposed in a transmission case 60 as a non-rotating member attached to the vehicle body, and a speed change unit 64 connected to the rotating machine MG and the engine 32 via a torque converter 62. The HEV transmission 34 also includes an MG connecting shaft 66. The rotating machine MG, the torque converter 62, and the speed change unit 64 are configured substantially symmetrically with respect to a center line, and the half below the center line is omitted in the schematic diagram of Fig. 3. Hereinafter, the transmission case 60 will be referred to as the case 60.

[0034] The rotating machine MG is a motor generator having a function as an electric motor that generates mechanical power from electric power and a function as a generator that generates electric power from mechanical power, and is, for example, a three-phase AC synchronous motor. The rotating machine MG has an MG torque Tmg, which is the torque of the rotating machine MG, and an MG rotation speed Nmg, which is the rotation speed of the rotating machine MG, controlled by the on-board control device 130. The rotating machine MG is connected to the MG connecting shaft 66 so as to be capable of transmitting power. That is, the rotating machine MG is connected to a power transmission path between the engine 32 and the torque converter 62 so as to be capable of transmitting power. The rotating machine MG is used as a power source SP for traveling, and generates power for traveling instead of or in addition to the engine 32. When the rotating machine MG is rotationally driven by the power of the engine 32 or the power input from the driving wheels DW side, it generates power by being regeneratively controlled to function as a generator, and when it is connected to the driving wheels DW, it generates regenerative brakes by regenerative operation. The rotating machine MG is connected to the crankshaft of the engine 32 directly or via a damper or the like (not shown). An engine disconnecting clutch or the like that connects and disconnects the power transmission between the rotary machine MG and the engine 32 may be provided.

[0035] The torque converter 62 includes a pump wheel 62a connected to the rotary machine MG via an MG connecting shaft 66, and a turbine wheel 62b connected to an input shaft 68 of the transmission unit 64. The torque converter 62 includes an LU clutch 70 serving as a known lock-up clutch that connects the pump wheel 62a and the turbine wheel 62b.

[0036] The transmission unit 64 is disposed in a power transmission path between the torque converter 62 and the transfer 36. An output shaft 72 of the transmission unit 64 is connected to the transfer 36. The transmission unit 64 is an automatic transmission that transmits the power of the power source SP to the drive wheels DW.

[0037] The transmission unit 64 is a known planetary gear type stepped automatic transmission that includes a plurality of planetary gear sets, for example a first planetary gear set 74 and a second planetary gear set 76, and a plurality of engagement devices, including a one-way clutch F1, a clutch C1, a clutch C2, a clutch C3, a brake B1, and a brake B2. Hereinafter, the clutches C1, C2, C3, brake B1, and brake B2 will be simply referred to as engagement device CB unless otherwise specified.

[0038] The engagement device CB is a known hydraulic friction engagement device configured with a multi-plate or single-plate clutch or brake pressed by a hydraulic actuator, a band brake tightened by a hydraulic actuator, etc. The engagement devices CB are each controlled by the on-board control device 130 to control the CB hydraulic pressure PRcb, which is the hydraulic pressure of the engagement device CB supplied from a hydraulic control circuit (not shown), thereby changing the CB torque Tcb, which is the torque capacity of each of the engagement devices CB, and thereby switching the operating state, i.e., the control state, such as an engaged state or a released state.

[0039] In the transmission unit 64, the rotating elements of the first planetary gear set 74 and the second planetary gear set 76 are partially connected to each other or to the input shaft 68, the case 60, or the output shaft 72, either directly or indirectly via an engagement device CB or a one-way clutch F1. The rotating elements of the first planetary gear set 74 are a sun gear S1, a carrier CA1, and a ring gear R1, and the rotating elements of the second planetary gear set 76 are a sun gear S2, a carrier CA2, and a ring gear R2.

[0040] The transmission unit 64 is a stepped transmission in which a plurality of speed stages (also referred to as gear stages) GS with different speed ratios (also referred to as gear ratios) γ (=input rotation speed Ni / output rotation speed No) are selectively formed by engaging any one of the engagement devices CB. The transmission unit 64 switches between the gear stages GS formed according to the accelerator operation of the driver (=operator), the vehicle speed V, etc., by the on-board control device 130. The input rotation speed Ni is the rotation speed of the input shaft 68, which is the input rotation speed of the transmission unit 64, and is the same value as the turbine rotation speed Nt, which is the rotation speed of the turbine shaft rotated and driven by the turbine impeller 62b. The output rotation speed No is the rotation speed of the output shaft 72, which is the output rotation speed of the transmission unit 64.

[0041] As shown in the operation engagement table of FIG. 4, for example, the transmission unit 64 has a plurality of gear stages GS, including four forward speeds from a first gear stage ("1st" in the figure) to a fourth gear stage ("4th" in the figure), and a reverse gear stage ("Rev" in the figure). The first gear stage has the largest gear ratio γ, and the higher the gear stage GS is, the fourth gear stage side where high-speed driving is possible, the smaller the gear ratio γ becomes. The operation engagement table of FIG. 4 summarizes the relationship between each gear stage GS and each control state of the engagement device CB. In FIG. 4, "○" indicates engagement, "(○)" indicates engagement during engine braking or coast downshift of the transmission unit 64, and a blank indicates release. When the gear stages GS are formed in the transmission unit 64, the transmission unit 64 is in a state in which power can be transmitted, that is, in a power transmission possible state. The neutral state of the transmission unit 64 ("N" in the figure) is a state in which the transmission unit 64 is unable to transmit power, i.e., a power transmission disabled state, which is achieved, for example, by all of the engagement devices CB being set to a disengaged state and power transmission in the transmission unit 64 being cut off.

[0042] Returning to FIG. 2, the transfer 36 includes, for example, an auxiliary transmission that changes the rotation transmitted from the output shaft 72 of the transmission unit 64 in two stages, high (transfer Hi) and low (transfer Lo), a distribution mechanism that distributes the torque output from the auxiliary transmission to the front propeller shaft 38 and the rear propeller shaft 46 at a predetermined distribution ratio, a differential lock device that limits the differential rotation of the front propeller shaft 38 and the rear propeller shaft 46, and a 2WD-4WD switching device that switches between 2WD that drives only the rear wheels 52 and 4WD that drives all wheels (front wheels 44, rear wheels 52). The high / low switching device, the differential lock device, and the 2WD-4WD switching device of the auxiliary transmission are electrically controlled by the on-board control device 130. A transfer 36 that can electrically control the torque distribution ratio to the front propeller shaft 38 and the rear propeller shaft 46 may also be employed.

[0043] The vehicle 30 further includes an automatic brake system 80 in relation to auto-cruise driving, which will be described later. The automatic brake system 80 electrically controls the brake force, i.e., brake hydraulic pressure, of each wheel brake 82fl, 82fr, 82rl, 82rr ​​provided on the front wheels 44 and the rear wheels 52 in accordance with a command from the on-board control device 130. Hereinafter, the wheel brakes 82fl, 82fr, 82rl, 82rr ​​will be simply referred to as wheel brakes 82 unless otherwise specified. In addition, brake hydraulic pressure is supplied to the wheel brakes 82 via a brake master cylinder by depressing a brake pedal (not shown), and the wheel brakes 82 mechanically generate a brake force corresponding to the brake hydraulic pressure, i.e., the brake operation force.

[0044] The vehicle 30 includes an on-board control device 130 as a control device that executes various types of control. The on-board control device 130 includes a plurality of electronic control devices for engine control, MG control, hydraulic control, etc., as necessary.

[0045] The on-board control device 130 receives various signals based on detection values ​​from various sensors provided in the vehicle 30 (for example, an engine rotation speed sensor 90, a turbine rotation speed sensor 92, an output rotation speed sensor 94, a MG rotation speed sensor 96, an accelerator opening sensor 98, a throttle valve opening sensor 100, a road surface gradient sensor 102, an acceleration sensor 104, a gear stage detection device 106, a vehicle distance sensor 108 such as a millimeter wave radar, an auto-cruise setting device 110, a platoon participation device 112, etc.), and outputs various signals (for example, an engine rotation speed sensor 90, a turbine rotation speed sensor 92, an output rotation speed sensor 94, a MG rotation speed sensor 96, an accelerator opening sensor 98, a throttle valve opening sensor 100, a road surface gradient sensor 102, an acceleration sensor 104, a gear stage detection device 106, a vehicle distance sensor 108 such as a millimeter wave radar, an auto-cruise setting device 110, a platoon participation device 112, etc.). The information supplied to the vehicle 106 includes the rotation speed Ne, turbine rotation speed Nt which is the same as the input rotation speed Ni, output rotation speed No corresponding to the vehicle speed V, MG rotation speed Nmg, accelerator opening θacc which is the amount of operation of an accelerator operating member such as an accelerator pedal and which represents the amount of output required by the driver, throttle valve opening θth which is the opening of the electronic throttle valve, road surface gradient Φ, longitudinal acceleration Ga and lateral acceleration Gb of the vehicle 30, gear stage GS of the transmission unit 64, inter-vehicle distance Dis to the preceding vehicle, auto-cruise setting information Acrui, and platoon participation information Cara. The gear stage detection device 106 can detect the gear stage GS from, for example, the control state of the engagement device CB of the transmission unit 64, but it may also specify the gear stage GS by calculating a gear ratio γ from the input rotation speed Ni and the output rotation speed No.

[0046] The auto-cruise setting device 110 is a device that selects auto-cruise driving, which performs constant speed driving and following driving, as an automatic driving that automatically controls the power source SP so that the vehicle 30 travels in a predetermined target driving state without the need for acceleration / deceleration operation by the driver. That is, the vehicle 30 is capable of auto-cruise driving, which automatically controls the engine 32 and the rotary machine MG according to the target vehicle speed Vt, etc., in addition to manual driving in which the engine 32 and the rotary machine MG are controlled according to the driver's acceleration / deceleration operation using the accelerator pedal, etc. The auto-cruise setting device 110 is a device that selects auto-cruise driving, sets the target vehicle speed Vt, increases / decreases the target vehicle speed Vt, and sets the target inter-vehicle distance Dt during following driving in which the vehicle travels following a preceding vehicle, and is disposed, for example, on a steering wheel, etc., and the target vehicle speed Vt, the target inter-vehicle distance Dt, etc. are input by the driver as auto-cruise setting information Acrui.

[0047] The platoon participation device 112 is a device that is operated when participating in a platoon as the leading vehicle 12le or the following vehicle 12fo, and whether to participate as the leading vehicle 12le or the following vehicle 12fo, the running order when participating as the following vehicle 12fo, etc. are input by the driver as platoon participation information Cara. The driver may input an identification number that can individually identify the vehicle 30, and transmission information including the number of gears GS of the mounted transmission unit 64, etc., as the platoon participation information Cara, but this is not necessary if the information is registered in advance in the on-board control device 130 by initial setting or the like. In addition, in this embodiment, a vehicle equipped with a continuously variable transmission or a manual transmission can also participate in the platoon as a platoon participating vehicle 12, in addition to the vehicle 30, and the transmission information related to the continuously variable transmission or the manual transmission is also set as the platoon participation information Cara in the on-board control device of the vehicle linked to the server 20. The platoon participation device 112 is configured using, for example, a touch panel that allows touch input, but may also be configured to allow input using a terminal such as a smartphone owned by the driver. In addition, platoon implementation information such as the date and time of platooning, the multiple platoon participating vehicles 12 participating in the platoon, whether the leading vehicle 12le or the following vehicle 12fo, and the running order of the following vehicles 12fo may be determined in advance by a platoon manager or the like and set in the server 20, and the platoon implementation information may be transmitted from the server 20 to the target platoon participating vehicles 12 and their drivers, etc.

[0048] The on-board control device 130 outputs various command signals (e.g., an engine control command signal Se for controlling the engine 32, an MG control command signal Smg for controlling the rotating machine MG, a shift control command signal Ssh for switching the gear stage GS of the shift unit 64, a transfer control command signal Stf for switching the power transmission state of the transfer 36, an automatic brake control command signal Sbr for controlling the automatic brake system 80, etc.) for controlling each device (e.g., the engine 32, the rotating machine MG, the transmission unit 64, the transfer 36, the automatic brake control command signal Sbr for controlling the automatic brake system 80) provided in the vehicle 30.

[0049] The on-board control device 130 also transmits and receives various information I to and from the server 20 via wireless communication R. For example, the on-board control device 130 receives control information Ic from the server 20 and transmits vehicle information Iv to the server 20. The control information Ic includes, for example, information on a platooning flag, which is a signal indicating that platooning is being performed, the platooning implementation information, information indicating the gear stage GS of the transmission 64, and information indicating the generated power of the rotary machine MG during regeneration operation, i.e., the regeneration amount. The vehicle information Iv includes, for example, vehicle identification information for identifying each of the platooning participating vehicles 12, running order information including the leading vehicle 12le, transmission information regarding the type and number of gear stages of the transmission 64 installed, information on the longitudinal acceleration Ga, i.e., the deceleration Gr, when the vehicle 30 is coasting, and information on the inter-vehicle distance Dis. The deceleration Gr represents the absolute value of the longitudinal acceleration Ga, which is a negative value. The on-board control device 130 may transmit and receive the various information I transmitted and received between the server 20 and a platoon participating vehicle 12 other than the vehicle 30 via wireless communication R. In addition, the on-board control device 130 may have stored in, for example, a non-volatile memory or the like, information on vehicle specifications such as the output characteristics of the engine 32, the output characteristics of the rotary machine MG, and the vehicle weight WTvs.

[0050] In order to realize various controls in the vehicle 30, the on-board control device 130 functionally comprises a power source control means, i.e., a power source control unit 132, a transmission control means, i.e., a transmission control unit 134, an auto-cruise control means, i.e., an auto-cruise control unit 136, and a platooning control means, i.e., a platooning control unit 138.

[0051] The power source control unit 132 is a hybrid control means, i.e., a hybrid control unit, which operates the engine 32 and the rotary machine MG in cooperation to execute hybrid drive control and the like. The power source control unit 132 calculates a drive demand amount for the vehicle 30 by the driver, for example, by applying the accelerator opening θacc and the vehicle speed V to a drive demand amount map. The drive demand amount map is a relationship that is experimentally or design-wise obtained and stored in advance, i.e., a predetermined relationship. The drive demand amount is a demand value for the drive amount output by the vehicle 30. The drive amount is, for example, a drive force Fr or a drive torque Tr at the drive wheels DW, and the drive demand amount is, for example, a required drive force Frdem or a required drive torque Trdem at the drive wheels DW. The power source control unit 132 outputs an engine control command signal Se for controlling the engine 32 and outputs an MG control command signal Smg for controlling the rotary machine MG so that the torque of the power source SP required to realize, for example, the required drive torque Trdem is obtained, taking into account a transmission loss, an auxiliary load, a gear ratio γ of the transmission unit 64, and the like.

[0052] The HEV transmission device 34 may be provided with, for example, an engine disconnecting clutch in a power transmission path between the rotating machine MG and the engine 32, which interrupts the power transmission between them. When the engine disconnecting clutch is provided, the power source control unit 132 can perform motor running, that is, BEV (Battery Electric Vehicle) running, in which the vehicle runs using only the rotating machine MG as the power source SP when the clutch is released and the engine 32 is stopped. For example, when the required drive torque Trdem can be satisfied only by the output of the rotating machine MG, the power source control unit 132 establishes the BEV drive mode as the drive mode. The BEV drive mode is an electric drive mode that allows BEV running (=electric running). On the other hand, when the required drive torque Trdem cannot be satisfied without using at least the output of the engine 32, the power source control unit 132 establishes the engine drive mode, that is, the HEV drive mode as the drive mode. The HEV drive mode is a hybrid drive mode that allows engine running, i.e., hybrid running (=HEV running), in which at least the engine 32 is used as the power source SP when the engine connection / disconnection clutch is in an engaged state. On the other hand, even if the required drive torque Trdem can be satisfied only by the output of the rotary machine MG, the power source control unit 132 establishes the HEV drive mode as the drive mode when the engine 32 or the like needs to be warmed up.

[0053] The transmission control unit 134 uses a shift map, which is a predetermined relationship, to determine whether or not the transmission unit 64 should be shifted, and outputs a shift control command signal Ssh for controlling the transmission unit 64 to be shifted as necessary. FIG. 5 is an example of a shift map when the transmission unit 64 is equipped with the four-speed transmission of FIG. 3. The shift map of FIG. 5 is a predetermined relationship having shift lines for determining whether or not the transmission unit 64 should be shifted, on a two-dimensional coordinate system having the vehicle speed V and the required driving torque Trdem as variables. The shift lines are an upshift line (see solid line) for determining whether or not an upshift should be performed, and a downshift line (see dashed line) for determining whether or not a downshift should be performed. The numbers "1" to "4" in the figure indicate the first to fourth gear stages. In the shift map of FIG. 5, the output rotation speed No may be used instead of the vehicle speed V, and the required driving force Frdem, accelerator opening θacc, throttle valve opening θth, etc. may be used instead of the required driving torque Trdem.

[0054] The auto-cruise control unit 136 executes auto-cruise driving as an automatic driving. Auto-cruise driving is autonomous driving without the need for acceleration / deceleration operation by the driver, and executes constant speed driving control for constant speed driving at the target vehicle speed Vt set by the auto-cruise setting device 110, and follow-up driving control for following while maintaining the target inter-vehicle distance Dt set by the auto-cruise setting device 110. In the constant speed driving control, the auto-cruise control unit 136 calculates the required driving torque Trdem required for driving at the target vehicle speed Vt, and outputs an engine control command signal Se for controlling the engine 32 and an MG control command signal Smg for controlling the rotary machine MG so that the torque of the power source SP required for realizing the required driving torque Trdem is obtained, taking into account the transmission loss, the auxiliary load, the gear ratio γ of the transmission unit 64, etc. Here, the required driving torque Trdem is obtained by feedback control, feedforward control, etc. based on the difference between the target vehicle speed Vt and the vehicle speed V, for example. On the other hand, in the following running control in which the vehicle follows the preceding vehicle while maintaining the target inter-vehicle distance Dt, the auto-cruise control unit 136 calculates the required driving torque Trdem required for following the preceding vehicle while the inter-vehicle distance Dis is the target inter-vehicle distance Dt, and controls the engine torque Te and the MG torque Tmg so that the required driving torque Trdem is obtained. The target inter-vehicle distance Dt is variably set according to, for example, the vehicle speed V. In addition, when the required driving torque Trdem is negative (minus), such as when the preceding vehicle is decelerating, the auto-cruise control unit 136 generates engine braking by the engine 32 or regenerative braking by the rotary machine MG, and, if necessary, obtains the negative required driving torque Trdem by combining it with the braking force of the wheel brake 82 controlled by the automatic brake system 80. In this embodiment, the negative driving torque Tr generated by the engine brake, regenerative braking, etc. is referred to as the driven torque Trr. Incidentally, even during this auto-cruise running, the transmission control unit 134 executes gear shift control to switch the gear stage GS of the transmission unit 64 in accordance with gear shift conditions such as the gear shift map of FIG.

[0055] The platoon running control unit 138 is involved in the platoon running control when the vehicle 30 participates in the platoon running as a platoon participating vehicle 12, and for example, sends platoon participation information Cara to the server 20 to participate in the platoon running, and performs auto-cruise running by the auto-cruise control unit 136. When the vehicle 30 participates in the platoon running as a following vehicle 12fo, the platoon running control unit 138 follows the preceding vehicle by maintaining a predetermined inter-vehicle distance Dis, for example a target inter-vehicle distance Dt, through following running control. Note that if the vehicle 30 is capable of autonomous running, which is an autonomous running that does not require steering operation in addition to acceleration / deceleration operation by the driver, or unmanned running, the platoon running control unit 138 may participate in the platoon running with autonomous running or unmanned running.

[0056] Here, the server 20 is functionally equipped with a platoon management control means, i.e., a platoon management control unit 22. The platoon management control unit 22 determines whether or not platooning is being performed. For example, the platoon management control unit 22 determines whether or not platooning is being performed based on various information I transmitted and received between the platoon participating vehicles 12. If the platoon management control unit 22 determines that platooning is being performed, it acquires vehicle information Iv required for managing the platooning and the driving amount from each of the platoon participating vehicles 12, and transmits control information Ic required for platooning control, driving amount control, and the like to each of the platoon participating vehicles 12.

[0057] Incidentally, when platooning is performed by repeating acceleration and coasting to maintain the target vehicle speed Vt and / or the target inter-vehicle distance Dt, if the deceleration Gr differs due to differences in the current vehicle state of each platoon participating vehicle 12 during coasting, the inter-vehicle distance Dis is likely to fluctuate. Or, even if the deceleration Gr of the platoon participating vehicles 12 during coasting is substantially the same, the inter-vehicle distance Dis may fluctuate due to differences in the running resistance of each platoon participating vehicle 12. The fluctuation of the inter-vehicle distance Dis is suppressed by control to maintain the target inter-vehicle distance Dt. However, since the control to maintain the target inter-vehicle distance Dt is performed after the occurrence of a fluctuation in the inter-vehicle distance Dis, it is considered to set the vehicle state such that the inter-vehicle distance Dis is originally difficult to fluctuate when switching to coasting before coasting. However, if the inter-vehicle distance Dis fluctuates in the direction of increasing, it is possible to give the driver a sense of security, so it is desirable to prevent the inter-vehicle distance Dis from fluctuating in the direction of decreasing.

[0058] Therefore, while platooning is being performed, the vehicle control device 150 performs driven torque adjustment control CTrr to control the driven torque Trr of each of the platoon participating vehicles 12 so that the platoon participating vehicles 12 are arranged in an order in which the estimated value of the deceleration Gr increases, starting from the leading vehicle 12le. In other words, while platooning is being performed, the vehicle control device 150 performs driven torque adjustment control CTrr in preparation for coasting before coasting begins. In this embodiment, the estimated value of the deceleration Gr is called the estimated deceleration Gre.

[0059] Specifically, the vehicle control device 150 calculates an estimated deceleration Gre for each platoon participating vehicle 12 based on the driven torque Trr when the vehicle coasts alone in the current vehicle state. For example, in a platoon participating vehicle 12 equipped with an engine 32, the on-board control device 130 calculates the driven torque Trr obtained by engine braking when the vehicle coasts based on the current engine rotation speed Ne. Alternatively, in a platoon participating vehicle 12 equipped with a rotary machine MG, the on-board control device 130 calculates the driven torque Trr obtained by regenerative braking when the vehicle coasts alone in the current vehicle state. In a platoon participating vehicle 12 equipped with an engine 32 and a rotary machine MG, the on-board control device 130 may calculate a total driven torque Trr by adding the driven torque Trr obtained by engine braking to the driven torque Trr obtained by regenerative braking. The on-board control device 130 calculates the estimated deceleration Gre based on the driven torque Trr and the running resistance RL when the vehicle coasts alone in the current vehicle state. For example, when the vehicle is traveling steadily on a flat road, the running resistance RL is the sum (=Fa+Frl)[N] of the air resistance Fa, which is a function of the vehicle speed V, and the rolling resistance Frl, which is a function of the vehicle weight WTv, which is the total weight of the vehicle itself WTvs plus the weight of the passengers and the like. The on-board control device 130 calculates the running resistance RL when the vehicle coasts alone in the current vehicle state, for example, by applying the current vehicle speed V and vehicle weight WTv to a running resistance map, which has a predetermined relationship. In this way, the vehicle control device 150 calculates the estimated deceleration Gre based on the driven torque Trr of each vehicle 12 participating in the platoon, based on the vehicle weight WTv.

[0060] The vehicle control device 150 may calculate the estimated deceleration Gre based on the driven torque Trr of each platoon participating vehicle 12 after the start of platooning, i.e., while platooning is being performed, or may calculate the estimated deceleration Gre before platooning is performed. By calculating the estimated deceleration Gre before platooning is performed, the platoon can be formed using information on the estimated deceleration Gre when platooning starts.

[0061] The driven torque adjustment control CTrr is performed when platooning is in progress and is not performed when platooning is not in progress. Therefore, the vehicle control device 150 determines whether platooning has started.

[0062] When the vehicle control device 150 determines that platooning has begun, that is, while platooning is being performed, it obtains information on the estimated deceleration Gre based on the driven torque Trr when each of the platoon-participating vehicles 12 coasts alone in the current vehicle state, and performs driven torque adjustment control CTrr.

[0063] In addition, there are cases where the estimated deceleration Gre cannot be calculated for any of the platoon participating vehicles 12. In such cases, the driven torque adjustment control CTrr cannot be performed. Therefore, when the vehicle control device 150 determines that platooning has started, it determines whether the estimated deceleration Gre based on the driven torque Trr of each platoon participating vehicle 12 can be acquired, i.e., whether it is possible to grasp it. When the vehicle control device 150 determines that the estimated deceleration Gre can be grasped, it performs the driven torque adjustment control CTrr.

[0064] In the driven torque adjustment control CTrr, the vehicle control device 150 identifies the platoon participating vehicles 12 whose estimated deceleration Gre can be changed by adjusting the driven torque Trr in the current vehicle state, and adjusts or changes the driven torque Trr so that a platoon can be formed in which the differences in estimated deceleration Gre due to the driven torque Trr between the vehicles before and after the platoon participating vehicle 12 are equal, while taking into account the range in which the estimated deceleration Gre can be changed. Then, the vehicle control device 150 determines the order of the platoon participating vehicles 12 based on the determined estimated deceleration Gre due to the driven torque Trr. The vehicle control device 150 forms a platoon in which the vehicle with the smallest estimated deceleration Gre is the leading vehicle 12le, and the vehicles moving further back have larger estimated deceleration Gre.

[0065] In the platoon participating vehicle 12 equipped with the engine 32 and the transmission unit 64, the on-board control device 130 controls the driven torque Trr obtained by engine braking by the engine 32 by changing the gear ratio γ of the transmission unit 64. That is, the on-board control device 130 can adjust the driven torque Trr and change the estimated deceleration Gre by changing the gear ratio γ of the transmission unit 64. When the transmission unit 64 is equipped with the four-speed transmission of FIG. 3, the on-board control device 130 can adjust the estimated deceleration Gre into four discontinuous steps by adjusting the driven torque Trr by the engine 32. Alternatively, when the transmission unit 64 is equipped with a continuously variable transmission, the on-board control device 130 can set a continuous estimated deceleration Gre by adjusting the driven torque Trr by the engine 32.

[0066] In the platoon participating vehicle 12 equipped with the rotating machine MG, the on-board control device 130 controls the driven torque Trr obtained by regenerative braking by the rotating machine MG by changing the regeneration amount of the rotating machine MG. In other words, the on-board control device 130 can adjust the driven torque Trr by changing the regeneration amount of the rotating machine MG, and change the estimated deceleration Gre. When the rotating machine MG is provided as the power source SP, the on-board control device 130 can set a continuous estimated deceleration Gre by adjusting the driven torque Trr by the rotating machine MG.

[0067] FIG. 6 is a diagram showing an example of deceleration settings in preparation for coasting during platooning. In FIG. 6, point a indicates the estimated deceleration Gre that can be set by the leading vehicle 12le in the current vehicle state. The range of solid line b indicates the range of estimated deceleration Gre that can be set by the following vehicle 12fo-1 in the current vehicle state. The range of solid line b corresponds to, for example, the range in which the continuously variable transmission can be changed, or the range in which the regeneration amount of the rotary machine MG can be changed. Points c and d each indicate the estimated deceleration Gre that can be set by the following vehicle 12fo-2 in the current vehicle state. Point d is a state in which the stepped transmission is downshifted with respect to point c. Even if the smallest estimated deceleration Gre (see point c) is set among the estimated decelerations Gre that can be set by the following vehicle 12fo-2, the estimated deceleration Gre will not be lower than the estimated decelerations Gre of the preceding leading vehicle 12le and the following vehicle 12fo-1, so "deceleration 2" corresponding to the smallest estimated deceleration Gre is selected as the estimated deceleration Gre of the following vehicle 12fo-2. The estimated deceleration Gre of the following vehicle 12fo-1 can be set based on "deceleration 1" set as the estimated deceleration Gre of the leading vehicle 12le and "deceleration 2" set as the estimated deceleration Gre of the following vehicle 12fo-2. In the embodiment of FIG. 6, "deceleration 1.5", which is the intermediate estimated deceleration Gre between the leading vehicle 12le and the following vehicle 12fo-2 (see point e), is set as the estimated deceleration Gre of the following vehicle 12fo-1. By performing the driven torque adjustment control CTrr described above, it is possible to suppress or prevent the inter-vehicle distance Dis from becoming shorter during coasting. The platoon in Fig. 6 is formed when the platoon starts, by calculating the estimated deceleration Gre that can be set by each vehicle, and determining the order of the platoon participating vehicles 12 and the estimated deceleration Gre, and then adjusting the driven torque Trr based on the order and the estimated deceleration Gre. Alternatively, the platoon in Fig. 6 is formed by rearranging the order of the platoon participating vehicles 12 while adjusting the driven torque Trr based on the order and the estimated deceleration Gre determined during platooning. Alternatively, the platoon in Fig. 6 is formed by adjusting the driven torque Trr while keeping the formed order based on the order and the estimated deceleration Gre determined during platooning.

[0068] Figure 7 is a flowchart explaining the main control operations of the vehicle control device 150, and is a flowchart explaining the control operations for preventing the inter-vehicle distance Dis between the platoon-participating vehicles 12 from becoming shorter when coasting during platooning, and is executed, for example, repeatedly.

[0069] In FIG. 7, each step of the flowchart corresponds to a function of the vehicle control device 150. In step (hereinafter, step will be omitted) S10, it is determined whether or not platooning has started. If the determination in S10 is negative, this routine is terminated. If the determination in S10 is positive, it is determined in S20 whether or not the estimated deceleration Gre due to the driven torque Trr of each platoon participating vehicle 12 can be grasped. If the determination in S20 is negative, this routine is terminated. If the determination in S20 is positive, in S30, the driven torque Trr of each vehicle is adjusted so that the steps of the estimated deceleration Gre of the platoon participating vehicles 12 become equal. Next, in S40, the platoon is formed in ascending order of the estimated deceleration Gre due to the driven torque Trr, that is, so that the estimated deceleration Gre increases toward the rear. Next, in S50, it is determined whether or not platooning has ended. If the determination in S50 is negative, this S50 is repeatedly executed. If the determination in S50 is positive, the driven torque adjustment control CTrr is terminated in S60.

[0070] As described above, according to this embodiment, while platooning is being performed, information on the estimated deceleration Gre based on the driven torque Trr when each platoon participating vehicle 12 coasts independently in the current vehicle state is acquired, and the driven torque Trr of each of the platoon participating vehicles 12 is controlled so that the platoon participating vehicles 12 are arranged in an order in which the estimated deceleration Gre increases from the leading vehicle 12le onwards, thereby preventing the actual deceleration Gr from becoming smaller even if the air resistance of the following vehicle 12fo is made smaller than that of the preceding vehicle. Therefore, it is possible to prevent the inter-vehicle distance Dis between the platoon participating vehicles 12 from becoming shorter when coasting during platooning.

[0071] Furthermore, according to this embodiment, in the platoon participating vehicle 12 equipped with the engine 32 and the transmission 64, the driven torque Trr obtained by engine braking is controlled by changing the gear ratio γ of the transmission 64, so that the driven torque Trr is easily controlled so that the platoon participating vehicles 12 are arranged in an order in which the estimated deceleration Gre increases starting from the leading vehicle 12le.

[0072] Furthermore, according to this embodiment, in the platoon participating vehicles 12 equipped with a rotating machine MG, the driven torque Trr obtained by regenerative braking is controlled by changing the amount of regeneration of the rotating machine MG, so that the driven torque Trr can be easily controlled so that the platoon participating vehicles 12 are arranged in an order in which the estimated deceleration Gre increases starting from the leading vehicle 12le.

[0073] Furthermore, according to this embodiment, the estimated deceleration Gre based on the driven torque Trr for each platoon participating vehicle 12 is calculated before platooning is started, so that the platoon can be formed taking into consideration the changeable range of the driven torque Trr when starting platooning. This makes it easier to control the driven torque Trr so that the platoon participating vehicles 12 are arranged in order of increasing estimated deceleration Gre starting from the leading vehicle 12le.

[0074] In addition, according to this embodiment, the estimated deceleration Gre based on the driven torque Trr of each vehicle 12 participating in the platoon is calculated based on the vehicle weight WTv, so that the estimated deceleration Gre of each vehicle 12 participating in the platoon is appropriately calculated in accordance with the weight of the occupants.

[0075] Next, another embodiment of the present invention will be described. In the following description, parts common to the embodiments are given the same reference numerals and the description thereof will be omitted. EXAMPLES

[0076] In the above-described first embodiment, the estimated deceleration Gre is calculated based on the running resistance RL when the vehicle coasts alone. The air resistance Fa included in the running resistance RL decreases in sequence from the leading vehicle 12le. Therefore, the estimated deceleration Gre of the following vehicle 12fo is made smaller than that of the following vehicle 12fo when the vehicle coasts alone by the amount of the smaller air resistance Fa.

[0077] Therefore, in this embodiment, the vehicle control device 150 calculates the estimated deceleration Gre taking into account the difference in air resistance Fa due to the arrangement order of the platoon participating vehicles 12. During platoon traveling, the vehicle control device 150 acquires information on the estimated deceleration Gre taking into account the difference in air resistance Fa due to the arrangement order of the platoon participating vehicles 12, and performs the driven torque adjustment control CTrr.

[0078] FIG. 8 is a diagram showing an example of deceleration setting that takes into account air resistance Fa in preparation for coasting during platooning. In FIG. 8, point a, the range of solid line b, point c, point d, and point e are the same as point a, the range of solid line b, point c, point d, and point e in FIG. 6, respectively. The air resistance Fa of the leading vehicle 12le is the largest, and the air resistance Fa is reduced in the order of the following vehicles 12fo-1 and 12fo-2. Since the air resistance Fa of the leading vehicle 12le is the same as the air resistance Fa when coasting alone, the estimated deceleration Gre set in the leading vehicle 12le remains as "deceleration 1" shown at point a. Since the air resistance Fa of the following vehicle 12fo-1 is reduced to be smaller than the air resistance Fa when coasting alone, the estimated deceleration Gre that can be set in the following vehicle 12fo-1 is set to be a range that is generally reduced from the range of solid line b by the amount that the air resistance Fa is reduced, as shown by the dashed line f. The estimated deceleration Gre, which is set as "deceleration 1.5", is also reduced by the amount that the air resistance Fa is reduced (see point g). The air resistance Fa of the following vehicle 12fo-2 is made even smaller than the air resistance Fa when the following vehicle 12fo-1 coasts alone, so the estimated deceleration Gre that can be set in the following vehicle 12fo-2 is made smaller than points c and d by the amount that the air resistance Fa is reduced, as shown by points h and i. Even if the estimated deceleration Gre of the leading vehicle 12le is set at point a, the estimated deceleration Gre of the following vehicle 12fo-1 is set at point g, and the estimated deceleration Gre of the following vehicle 12fo-2 is set at point h, a certain difference can be provided in the estimated deceleration Gre, but the difference is smaller than when they are set at points a, e, and c. Therefore, in the following vehicle 12fo-2, the stepped transmission is downshifted to change the gear stage, so that the estimated deceleration Gre of the following vehicle 12fo-2 is set at point i. Also, the estimated deceleration Gre of the following vehicle 12fo-1 is set to an intermediate estimated deceleration Gre between points a and i (see point j). This creates a state equivalent to the difference in estimated deceleration Gre when set at points a, e, and c. In the embodiment of FIG. 8, it was possible to set an estimated deceleration Gre that increases from the leading vehicle 12le to the rear, without changing the estimated deceleration Gre in the following vehicle 12fo-2.If it is not possible to set the estimated deceleration Gre to increase from the leading vehicle 12le to the rear, the estimated deceleration Gre of any vehicle is changed or the order of the platoon participating vehicles 12 is rearranged so that the estimated deceleration Gre increases from the leading vehicle 12le to the rear. The calculation of the estimated deceleration Gre taking into account the air resistance Fa may be performed before the start of platooning, or may be appropriately applied to the driven torque adjustment control CTrr by looking at the difference with the estimated deceleration Gre assumed during platooning. The assumed estimated deceleration Gre is the estimated deceleration Gre calculated using the air resistance Fa when coasting alone.

[0079] As described above, according to this embodiment, information on the estimated deceleration Gre is obtained that takes into account the difference in air resistance Fa due to the order in which the vehicles 12 joining the platoon are arranged, so that even if the air resistance of the following vehicle 12fo is smaller than that of the preceding vehicle, the actual deceleration Gr is further suppressed or avoided from becoming smaller. EXAMPLES

[0080] In the above-described first and second embodiments, when the vehicles coast while traveling in a convoy, the driven torque adjustment control CTrr may be performed, causing the inter-vehicle distance Dis between any of the convoy participating vehicles 12 to become sufficiently longer than the target inter-vehicle distance Dt. In such a case, it is not necessary to perform the driven torque adjustment control CTrr.

[0081] Therefore, in this embodiment, the vehicle control device 150 ends the driven torque adjustment control CTrr when the inter-vehicle distance Dis between any of the platoon participating vehicles 12 exceeds a predetermined end determination threshold Dend that is longer than a predetermined inter-vehicle distance Dis, for example, a target inter-vehicle distance Dt, due to control of the driven torque Trr, i.e., the driven torque adjustment control CTrr. The predetermined end determination threshold Dend is a predetermined threshold for determining that the inter-vehicle distance Dis has become sufficiently longer than the target inter-vehicle distance Dt, for example, during coasting.

[0082] Fig. 9 is a flowchart explaining the main control operations of the vehicle control device 150, and is a flowchart explaining the control operations for suppressing a decrease in the inter-vehicle distance Dis between the platoon participating vehicles 12 during coasting while traveling in a platoon, and is executed repeatedly, for example. Fig. 9 is an embodiment different from the flowchart of Fig. 7. Fig. 9 mainly describes the points different from Fig. 7.

[0083] In Fig. 9, each step of the flowchart corresponds to a function of the vehicle control device 150. Following S40, in S45, it is determined whether or not the vehicle is coasting. If the determination in S45 is positive, it is determined in S48 whether or not the inter-vehicle distance Dis has exceeded a predetermined end determination threshold Dend. If the determination in S48 is negative, the above S45 is executed. If the determination in S45 is negative, the above S50 is executed. If the determination in S50 is negative, the above S45 is executed. If the determination in S48 is positive, or if the determination in S50 is positive, the above S60 is executed.

[0084] As described above, according to this embodiment, when the driven torque adjustment control CTrr causes the inter-vehicle distance Dis between any of the platoon participating vehicles 12 to exceed a predetermined termination judgment threshold Dend, the driven torque adjustment control CTrr is terminated, so that if a situation arises in which the inter-vehicle distance Dis between the platoon participating vehicles 12 can be avoided from becoming shorter, the inter-vehicle distance Dis is prevented from becoming longer than that.

[0085] Although the embodiment of the present invention has been described in detail above with reference to the drawings, the present invention can be applied to other embodiments.

[0086] For example, the second and third embodiments may be combined with the first embodiment.

[0087] 7 and 9 may be executed by the server 20 included in the vehicle control device 150. Also, in the above-described embodiment, some or all of the steps in the flowcharts in Fig. 7 and 9 may be executed by the on-board control device 130 included in the vehicle control device 150.

[0088] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various modified and improved forms based on the knowledge of those skilled in the art. [Explanation of symbols]

[0089] 12: Vehicles participating in the platoon 12le: Leading vehicle (vehicle participating in the convoy) 12fo (12fo-1, 12fo-2, 12fo-n): Following vehicles (vehicles participating in the platoon) 20: Server (vehicle control device) 32: Engine (power source) 44: Front wheels (drive wheels) 52: Rear wheel (drive wheel) 64: Transmission (automatic transmission) 130: Vehicle control device (vehicle control device) 150: Vehicle control device DW: Drive wheel MG: Rotating machine (power source) R: Wireless communication SP: Power source

Claims

1. A vehicle control device that connects each of platoon participating vehicles, including a lead vehicle and a follow vehicle that automatically follows the lead vehicle in a single file at a predetermined vehicle distance from the lead vehicle, via wireless communication and controls the platoon traveling of the platoon participating vehicles, During the platoon traveling, information on an estimated value of deceleration based on a driven torque when the platoon participating vehicle coasts alone in a current vehicle state is acquired for each of the platoon participating vehicles, and the driven torque of each of the platoon participating vehicles is controlled so that the platoon participating vehicles are arranged in an order of increasing estimated value of deceleration starting from the leading vehicle, A vehicle control device characterized in that, in a vehicle participating in a platoon equipped with a rotating machine as a power source, the driven torque obtained by regenerative braking due to the regenerative operation of the rotating machine is controlled by changing the amount of regeneration of the rotating machine.

2. A vehicle control device that connects each of platoon participating vehicles, including a lead vehicle and a follower vehicle that automatically follows the lead vehicle in a single file at a predetermined vehicle distance from the lead vehicle, via wireless communication and controls the platoon traveling of the platoon participating vehicles, During the platoon traveling, information on an estimated value of deceleration based on a driven torque when the platoon participating vehicle coasts alone in a current vehicle state is acquired for each of the platoon participating vehicles, and the driven torque of each of the platoon participating vehicles is controlled so that the platoon participating vehicles are arranged in an order of increasing estimated value of deceleration starting from the leading vehicle, A vehicle control device for a platooning vehicle equipped with an engine as a power source and an automatic transmission that transmits the power of the engine to the drive wheels, characterized in that the driven torque obtained by engine braking due to friction of the engine is controlled by changing the gear ratio of the automatic transmission.

3. The vehicle control device according to claim 2, characterized in that in the platoon-participating vehicle equipped with a rotating machine as a power source, the driven torque obtained by regenerative braking due to regenerative operation of the rotating machine is controlled by changing the amount of regeneration of the rotating machine.

4. 4. The vehicle control device according to claim 1, further comprising: acquiring information on the estimated value of the deceleration taking into account a difference in air resistance due to an arrangement order of the vehicles participating in the platoon.

5. 5. The vehicle control device according to claim 1, wherein the estimated value of the deceleration based on the driven torque of each of the vehicles participating in the platoon is calculated before the platoon travel is performed.

6. 6. The vehicle control device according to claim 1, wherein the estimated value of the deceleration based on the driven torque of each vehicle participating in the platoon is calculated based on a vehicle weight.

7. A vehicle control device as described in any one of claims 1 to 6, characterized in that when the control of the driven torque causes the inter-vehicle distance between any of the platoon-participating vehicles to exceed a predetermined termination judgment threshold value that is longer than the predetermined inter-vehicle distance, the control of the driven torque is terminated.

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