Autonomous Driving System

Abstract

To enable an early determination of when the automated driving along a predetermined travel route becomes impossible.SOLUTION: An automated driving system estimates heat dissipation performance of a vehicle (a value of a vehicle performance parameter correlating to a vehicle performance used to determine whether or not the automated driving is possible) and an amount of heat dissipation required to implement the automated driving of the vehicle along a travel route (a value of a necessary performance parameter correlating to the vehicle performance required to implement the automated driving of the vehicle along the travel route). When the value of the vehicle performance parameter is less than the value of the necessary performance parameter, the automated driving system determines not to execute the automated driving of the vehicle along a planned travel route, and performs any of: setting another travel route; returning the vehicle to the repair shop; or evacuating the vehicle.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an automated driving system. [Background technology]

[0002] In recent years, autonomous driving systems have been developed to enable vehicles to travel autonomously. Conventional autonomous driving systems control the vehicle to evacuate (for example, drive to the shoulder of the road) and then stop the vehicle when it becomes unable to drive autonomously along a preset route. When the vehicle stops, the occupants cannot move in the vehicle. As a result, the occupants must wait until a rescue vehicle arrives.

[0003] Patent Document 1 discloses an autonomous driving system that can solve this problem. The autonomous driving system of Patent Document 1 determines whether the vehicle can continue to drive autonomously if a sensor (camera or radar) required for autonomous driving fails. The autonomous driving system also stores multiple destinations. Even if the sensor fails, the autonomous driving system selects a reachable destination from among the multiple destinations if the vehicle can continue to drive autonomously. The driver is notified of this reachable destination. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-111098 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the automated driving system disclosed in Patent Document 1 changes the destination after a sensor failure occurs. In other words, this automated driving system changes the destination after automated driving becomes impossible while the vehicle is traveling toward the previous destination. As a result, the travel toward the previous destination is wasted.

[0006] The inventor of the present invention came up with the idea that if it were possible to predict in advance when automatic driving along a preset driving route would become impossible, this unnecessary driving could be eliminated.

[0007] An object of the present invention is to enable early determination of when automatic driving along a preset driving route becomes impossible. [Means for solving the problem]

[0008] The solution of the present invention to achieve the above object is based on an autonomous driving system that controls autonomous driving of a vehicle along a predetermined driving route. The autonomous driving system includes a vehicle performance estimation unit, a required performance estimation unit, and an autonomous driving control unit. The vehicle performance estimation unit estimates the value of a vehicle performance parameter correlated with vehicle performance used to determine whether autonomous driving of the vehicle along the planned driving route is possible if the vehicle is driven autonomously along the planned driving route, at least one of before the autonomous driving begins and during the autonomous driving along the planned driving route. The required performance estimation unit estimates the value of a required performance parameter correlated with vehicle performance required to drive the vehicle along the planned driving route. The autonomous driving control unit performs autonomous driving of the vehicle along the planned driving route on the condition that the value of the vehicle performance parameter is equal to or greater than the value of the required performance parameter, and does not perform autonomous driving of the vehicle along the planned driving route if the value of the vehicle performance parameter is less than the value of the required performance parameter. Furthermore, when a minor collision occurs to the vehicle, the vehicle performance estimation unit sets a reduction amount for reducing the estimated value of the vehicle performance parameter in accordance with the load of the minor collision.By this specification, if the value of the estimated vehicle performance parameter is less than the value of the estimated required performance parameter, the automated driving of the vehicle along the planned driving route will not be performed. In other words, it is possible to predict in advance whether the vehicle performance required to perform the automated driving of the vehicle along the planned driving route has not been obtained, or whether there is a possibility that the required vehicle performance will not be obtained. This makes it possible to eliminate unnecessary driving.

[0009] Furthermore, the vehicle performance used to determine whether autonomous driving is possible is the heat dissipation performance of a cooling system that dissipates heat from heat-generating devices mounted on the vehicle. The vehicle performance parameter is the amount of heat that can be dissipated by the cooling system when autonomous driving of the vehicle is performed along the planned driving route. The required performance parameter is the amount of heat dissipation required by the cooling system that exceeds the amount of heat generated by the devices when autonomous driving of the vehicle is performed along the planned driving route. This makes it possible to estimate in advance whether autonomous driving of the vehicle along the planned driving route is possible based on the heat dissipation performance of the cooling system for dissipating heat from heat-generating devices. In other words, it is possible to estimate in advance that the heat dissipation performance of the cooling system will be insufficient during autonomous driving along the driving route, making it impossible to continue autonomous driving.

[0010] Furthermore, the vehicle performance estimation unit sets lower estimated values ​​of the vehicle performance parameters according to the deterioration over time of the vehicle performance used to determine whether autonomous driving is possible. This makes it possible to set estimated values ​​of the vehicle performance parameters according to the deterioration over time of the vehicle performance. Therefore, it is possible to accurately estimate over a long period of time whether the vehicle performance required to perform autonomous driving of the vehicle along the planned driving route is obtained.

[0011] The automated driving system also includes a route resetting unit. When the value of the vehicle performance parameter is less than the required performance parameter, the route resetting unit sets a different route from the planned route, where the value of the vehicle performance parameter is equal to or greater than the required performance parameter, as a route to be controlled by automated driving of the vehicle. This allows automated driving of the vehicle to be performed along a different route even if automated driving of the vehicle along the originally planned route is not performed. In other words, this eliminates a situation in which occupants are unable to move until a rescue vehicle arrives when automated driving of the vehicle along the originally planned route is not performed.

[0012] The automated driving system also includes a driving condition presentation unit. When the value of the vehicle performance parameter is less than the required performance parameter, the driving condition presentation unit presents to the vehicle user driving conditions that are different from the driving conditions of the planned driving route and in which the value of the vehicle performance parameter is equal to or greater than the required performance parameter. This allows the vehicle user to select a driving route different from the originally planned driving route even if automated driving of the vehicle along the originally planned driving route is not performed. In other words, even if automated driving of the vehicle along the originally planned driving route is not performed, automated driving of the vehicle can be performed along a driving route desired by the vehicle user. [Effects of the Invention]

[0013] In the present invention, if the value of a vehicle performance parameter correlated with the vehicle performance used to determine whether autonomous driving is possible is less than the value of a required performance parameter correlated with the vehicle performance required to perform autonomous driving, autonomous driving of the vehicle along the planned driving route is not performed. This makes it possible to make an early determination when autonomous driving along a predetermined driving route is impossible. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of an automatic driving system mounted on a vehicle according to an embodiment. [Figure 2] FIG. 2(a) is a circuit diagram that schematically shows a battery cooling system mounted on a vehicle according to an embodiment, and FIG. 2(b) is a circuit diagram that schematically shows a high-temperature cooling circuit in the battery cooling system. [Figure 3] FIG. 3(a) is a diagram showing an example of the relationship between the estimated dissipable heat amount and the estimated heat generation amount, and FIG. 3(b) is a diagram showing an example of the relationship between the estimated dissipable heat amount and the estimated heat generation amount when heat dissipation performance has decreased. [Figure 4] FIG. 4 is a flowchart showing the procedure of the autonomous driving feasibility determination process. [Figure 5] FIG. 5 is a block diagram showing a schematic configuration of an automatic driving system mounted on a vehicle according to a modified example. [Figure 6] FIG. 6 is a circuit diagram showing a schematic example of a multiple redundant design of a battery cooling system. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, the present invention will be described as being applied to an electric vehicle. However, the present invention is not limited to electric vehicles. The present invention can also be applied to automobiles equipped with engines (conventional vehicles, hybrid vehicles, plug-in hybrid vehicles) and fuel cell vehicles. Furthermore, this embodiment will be described as being applied to an autonomous vehicle whose driving route is set by a navigation device. The present invention can also be applied to an autonomous vehicle whose driving route is set according to destination setting information transmitted from a vehicle management center.

[0016] Furthermore, in this embodiment, the dissipable heat amount, which is the heat dissipation performance of the vehicle, and the required heat dissipation amount required to perform autonomous driving of the vehicle along the travel route are estimated. A case where the feasibility of autonomous driving is determined based on these estimated information will be described as an example. The dissipable heat amount corresponds to the "vehicle performance parameter correlated with vehicle performance used to determine the feasibility of autonomous driving when autonomous driving of the vehicle along the planned travel route is performed" of the present invention. The required heat dissipation amount corresponds to the "required performance parameter correlated with vehicle performance required to perform autonomous driving of the vehicle along the planned travel route" of the present invention.

[0017] -Autonomous driving system- First, an overview of the autonomous driving system will be described. Fig. 1 is a diagram showing the schematic configuration of an autonomous driving system 100 installed in a vehicle according to this embodiment. As shown in Fig. 1, the autonomous driving system 100 according to this embodiment includes an autonomous driving ECU 110, which is the center of control for the autonomous driving of the vehicle. The following are connected to this autonomous driving ECU 110: a surrounding condition sensor 121, a vehicle condition sensor 122, a driving operation sensor 123, an external communication device 130, a GPS receiver 140, a map database 150, a navigation device 160, an actuator 170, an auxiliary device 180, and an HMI (Human Machine Interface) 190.

[0018] The surrounding condition sensor 121 acquires information about the conditions around the vehicle (hereinafter, sometimes referred to as the host vehicle). This information about the conditions around the host vehicle includes information about the road ahead of the host vehicle and obstacles around the host vehicle. The surrounding condition sensor 121 is equipped with, for example, a camera, a lidar (LIDAR), a millimeter-wave radar sensor, etc. The surrounding condition sensor 121 does not necessarily need to include all of these, and may also include other components as long as it is a sensor that can detect the surrounding conditions necessary for performing autonomous driving. The surrounding condition sensor 121 also includes an outside air temperature sensor, etc. The surrounding condition sensor 121 transmits the acquired information to the autonomous driving ECU 110. The vehicle condition sensor 122 is, for example, a vehicle speed sensor, a longitudinal acceleration sensor, a lateral acceleration sensor, and a yaw rate sensor. The vehicle condition sensor 122 transmits information about the detection results to the autonomous driving ECU 110. The driving operation sensor 123 detects the amount of operation when autonomous driving is canceled. The driving operation sensor 123 is, for example, an accelerator operation amount sensor, a brake operation amount sensor, a brake switch, a steering angle sensor, and a shift position sensor. The driving operation sensor 123 transmits information on the detection results to the autonomous driving ECU 110. The external communication device 130 is a device that communicates between the host vehicle and the outside of the host vehicle. The external communication device 130 acquires information on the surrounding environment of the host vehicle. For example, the external communication device 130 acquires traffic information and the like related to the driving environment of the host vehicle through communication with an information center. The external communication device 130 also acquires traffic information and the like through road-to-vehicle communication, which is communication with a roadside device installed on a road. The external communication device 130 also acquires traffic information and the like through vehicle-to-vehicle communication, which is communication with an external communication device 130 installed in another vehicle. The external communication device 130 transmits the acquired surrounding environment information to the autonomous driving ECU 110. The GPS receiver 140 receives signals from GPS satellites and measures the position of the host vehicle. The GPS receiver 140 transmits the vehicle's position information, which is the measurement result, to the autonomous driving ECU 110. The map database 150 is a database that contains map information. The database is stored in a storage device such as a hard disk mounted on the vehicle.The map information includes, for example, road position information, road shape information, intersection and branch point position information, road type information (information that can distinguish between expressways, highways, general roads, etc.), and information indicating the number of lanes. The navigation device 160 generates information about a driving route that guides the vehicle to a destination set by the occupant. The navigation device 160 calculates a driving route to the destination based on the current position information of the vehicle detected by the GPS receiver 140 and the map information in the map database 150. The navigation device 160 transmits information about the driving route to the autonomous driving ECU 110 as navigation information. The navigation device 160 also has a location registration function that registers any location. When autonomous driving is not performed (when the vehicle is driven by the occupant), the navigation device 160 uses a display and speaker (not shown) to guide the driver to the destination.

[0019] The actuators 170 are a driving force actuator, a brake actuator, and a steering actuator. The driving force actuator is a driving motor and a motor drive circuit that controls the power supply to the driving motor. For example, if the vehicle's brake device is hydraulic, the brake actuator is a hydraulic friction braking mechanism and a hydraulic control circuit that controls the hydraulic pressure of the wheel cylinders of the hydraulic friction braking mechanism. If the vehicle is equipped with an electric power steering device, the steering actuator is a steering motor incorporated in the steering mechanism and a motor drive circuit that controls the power supply to the steering motor. The autonomous driving ECU 110 sends a driving force control signal corresponding to the target driving force to the driving force actuator. As a result, the driving motor generates the target driving force. The autonomous driving ECU 110 also sends a braking force control signal corresponding to the target braking force to the brake actuator. As a result, the brake device generates the target braking force. The autonomous driving ECU 110 also sends a steering control signal corresponding to the target steering torque (or target steering angle) to the steering actuator. As a result, the electric power steering device generates the target steering torque. Through the above operations, the vehicle is automatically driven.

[0020] Auxiliary equipment 180 is a general term for equipment not included in actuator 170. Examples of auxiliary equipment 180 include turn signals, headlights, and wipers. The autonomous driving ECU 110 outputs an activation signal to the auxiliary equipment 180. This controls the operation of the auxiliary equipment 180. The HMI 190 is an interface that inputs and outputs information between the occupant and the autonomous driving system 100. The HMI 190 is composed of, for example, a display that displays text or image information, a speaker and buzzer that generate sound, operation buttons that the occupant uses to perform input operations, a touch panel, a microphone, and the like.

[0021] The autonomous driving ECU 110 includes, for example, a processor such as a CPU, a ROM for storing a control program, a RAM for temporarily storing data, and input / output ports. When the autonomous driving ECU 110 performs autonomous driving, it monitors the surroundings of the host vehicle based on information provided by the surrounding condition sensor 121. Meanwhile, the autonomous driving ECU 110 controls the operation of the actuator 170 to ensure that the host vehicle travels safely along a set travel route. The autonomous driving ECU 110 includes an autonomous driving feasibility determination unit 300 and an autonomous driving control unit 400. The autonomous driving feasibility determination unit 300 and the autonomous driving control unit 400 are functional units implemented by the control program. The autonomous driving feasibility determination unit 300 has a function of determining whether or not the host vehicle can travel along a preset travel route. The autonomous driving control unit 400 controls the autonomous driving of the vehicle in accordance with the determination of the autonomous driving feasibility determination unit 300. The autonomous driving feasibility determination unit 300 and the autonomous driving control unit 400 will be described later.

[0022] -Battery cooling system- Next, a battery cooling system for cooling the battery (a heat-generating device) that supplies power to each motor will be described. In this embodiment, the heat dissipation performance of the battery cooling system corresponds to the "vehicle performance used to determine whether autonomous driving is possible" of the present invention. In other words, if the heat dissipation performance of the battery cooling system is estimated to be sufficiently high (if the heat dissipation performance for cooling the battery when performing autonomous driving is estimated to be sufficiently high), it is determined that autonomous driving (autonomous driving of the vehicle along the planned driving route) is possible. On the other hand, if the performance of the battery cooling system is estimated to be insufficient (if the heat dissipation performance for cooling the battery when performing autonomous driving is estimated to be insufficient) or if it is estimated that the performance of the battery cooling system may be insufficient (if it is estimated that the heat dissipation performance for cooling the battery when performing autonomous driving may be insufficient), it is determined that autonomous driving is impossible. The configuration and operation for these determinations will be described later. FIG. 2(a) is a circuit diagram schematically illustrating a battery cooling system 200. The battery cooling system 200 cools the battery 10 installed in the vehicle. As shown in FIG. 2(a), the battery cooling system 200 includes a high-temperature cooling circuit HT, a refrigerant circuit RE, and a battery circuit Bat. The high-temperature cooling circuit HT is a circuit that circulates coolant. The high-temperature cooling circuit HT is a circulation circuit in which a radiator 201, an electric radiator fan 202, a water pump 203, and a water-cooled condenser 212 are connected by piping. The radiator 201 dissipates heat from the coolant to the outside of the vehicle. The electric radiator fan 202 provides forced air to the radiator 201. The water pump 203 circulates the coolant within the high-temperature cooling circuit HT. The water-cooled condenser 212 exchanges heat between the coolant and the refrigerant. The coolant circulates through the high-temperature cooling circuit HT. The refrigerant circulates through the refrigerant circuit RE.

[0023] As shown in FIG. 2(b), the high-temperature cooling circuit HT is provided with a flow rate sensor 205 and a temperature sensor 206. The flow rate sensor 205 detects the flow rate of the coolant. The temperature sensor 206 detects the temperature of the coolant (for example, the temperature of the coolant at the outlet side of the water-cooled condenser 212). Information detected by these sensors is sent to the automatic driving ECU 110. Information on the rotation speed of the electric radiator fan 202 is also sent to the automatic driving ECU 110. The refrigerant circuit RE circulates the refrigerant while causing it to change phase. As shown in FIG. 2(a), the refrigerant circuit RE is a circulation circuit in which a compressor 211, the water-cooled condenser 212, a cooler 213, and a chiller 214 are connected by piping. The compressor 211 compresses the refrigerant. In the water-cooled condenser 212, heat exchange occurs between the coolant in the high-temperature cooling circuit HT and the refrigerant. This heat exchange causes the refrigerant to condense, and the heat of the refrigerant is released to the coolant in the high-temperature cooling circuit HT. A portion of the refrigerant condensed in the water-cooled condenser 212 expands in the cooler 213. This cools the air around the cooler 213. Another portion of the refrigerant condensed in the water-cooled condenser 212 expands in the chiller 214. This absorbs heat from the coolant circulating through the battery circuit Bat (cools the coolant). The battery circuit Bat is a circuit that circulates coolant for cooling the battery 10. The battery circuit Bat is a circulation circuit in which a water pump 221, the chiller 214, and the battery 10 (a coolant passage provided in the battery 10) are connected by piping. The water pump 221 circulates the coolant within the battery circuit Bat. The coolant cooled by the chiller 214 is introduced into the battery 10. This absorbs heat from the battery 10 (cools the battery 10). The battery 10 generates heat as it charges and discharges power. To start or continue autonomous driving of the vehicle, the temperature of the battery 10 needs to be maintained at or below a predetermined temperature. Since the battery 10 is cooled by the operation of the battery cooling system 200 described above, in order to start or continue autonomous driving, it is necessary to ensure sufficient heat dissipation performance in each of the circuits HT, RE, and Bat. In this embodiment, it is estimated in advance whether or not this heat dissipation performance is sufficiently ensured.This estimation in advance does not only include estimation before autonomous driving begins. Estimation in advance also includes estimation before a shortage of heat dissipation performance occurs while driving along a driving route after autonomous driving has begun. The following describes the estimation of the heat dissipation performance of the high-temperature cooling circuit HT, among the estimations of the heat dissipation performance of each circuit HT, RE, and Bat. Also, the following describes a case where the feasibility of autonomous driving is determined based on the heat dissipation performance of the high-temperature cooling circuit HT. Note that the heat dissipation performance of the refrigerant circuit RE and the battery circuit Bat is also estimated in a similar manner, and the feasibility of autonomous driving is determined based on this heat dissipation performance.

[0024] The following describes the autonomous driving feasibility determination unit 300, which estimates the heat dissipation performance of the high-temperature cooling circuit HT and determines whether autonomous driving is possible. As shown in Fig. 1, the autonomous driving feasibility determination unit 300 includes an information acquisition unit 301, a vehicle performance estimation unit 302, a required performance estimation unit 303, a performance determination unit 304, a route resetting unit 305, and an autonomous driving feasibility information output unit 306.

[0025] The information acquisition unit 301 acquires information for estimating the heat dissipation performance of the high-temperature cooling circuit HT. This heat dissipation performance includes not only the current heat dissipation performance but also the heat dissipation performance when the vehicle is autonomously driven along the planned driving route. This information includes the coolant flow rate, the coolant temperature, the vehicle speed, the rotation speed of the electric radiator fan 202, the outside air temperature, etc. The coolant flow rate is information output from the flow rate sensor 205. The coolant temperature is information output from the temperature sensor 206. The vehicle speed is information output from the vehicle speed sensor. The vehicle speed information also includes information about the vehicle speed (planned vehicle speed) at each point when the vehicle is autonomously driven along the planned driving route. The rotation speed of the electric radiator fan 202 is information recognized from a control signal of the electric radiator fan 202. The outside air temperature is information output from the outside air temperature sensor. The outside air temperature information also includes information about the outside air temperature at each point when the vehicle is autonomously driven along the planned driving route. This information is, for example, information about the outside air temperature acquired by the external communication device 130.

[0026] The vehicle performance estimation unit 302 estimates the heat dissipation performance of the high-temperature cooling circuit HT based on the various pieces of information acquired by the information acquisition unit 301. Specifically, the vehicle performance estimation unit 302 not only estimates the heat dissipation performance of the high-temperature cooling circuit HT at the current time (e.g., before the start of autonomous driving), but also estimates the heat dissipation capacity as the heat dissipation capacity. This heat dissipation capacity refers to the heat dissipation capacity of the high-temperature cooling circuit HT when the vehicle is driven autonomously along the planned driving route. This heat dissipation capacity corresponds to the "value of a vehicle performance parameter correlated with vehicle performance used to determine whether autonomous driving is possible" of the present invention. For example, the greater the coolant flow rate, the greater the available heat dissipation capacity (value of the vehicle performance parameter). The lower the coolant temperature, the greater the available heat dissipation capacity. The higher the vehicle speed, the greater the amount of heat dissipation using the wind generated by driving, and therefore the greater the available heat dissipation capacity. The higher the rotation speed of the electric radiator fan 202, the greater the available heat dissipation capacity. The lower the outside air temperature, the greater the amount of heat dissipated by the radiator 201, and therefore the greater the amount of heat that can be dissipated. The relationship between the amount of heat that can be dissipated and the above-mentioned factors is determined in advance through experiments and simulations. The above-mentioned factors are the flow rate of the coolant, the temperature of the coolant, the vehicle speed, the rotation speed of the electric radiator fan 202, and the outside air temperature. The above-mentioned determined relationship is stored in the ROM of the autonomous driving ECU 110 as a dissipation amount map. This estimation of the dissipation amount is performed when the driving route to the destination is set. Furthermore, this estimation of the dissipation amount continues even during autonomous driving along the driving route.

[0027] The required performance estimation unit 303 acquires information about the driving route (driving route to the destination) set by the navigation device 160. Then, based on the information about the driving route, the required performance estimation unit 303 estimates the heat dissipation performance of the high-temperature cooling circuit HT required to reach the destination as the required heat dissipation performance. Specifically, from the information about the driving route, the unit 303 estimates the output (required motor output), the amount of current (amount of current required to obtain the required motor output), and the vehicle speed (vehicle speed when traveling at the required output) at each point on the driving route. The unit 303 then estimates, as the required heat dissipation performance, the heat dissipation performance that can obtain a dissipable heat amount (required dissipable heat amount) that exceeds the heat generation amount (estimated heat generation amount) when traveling along the driving route with these output, current amount, and vehicle speed. This required dissipable heat amount corresponds to the "value of the required performance parameter correlated with the vehicle performance required to perform autonomous driving of the vehicle" in this invention. For example, the greater the output, the greater the required dissipable heat amount (value of the required performance parameter). The greater the amount of current, the greater the required dissipable heat amount. With respect to the vehicle speed, the required dissipable heat quantity is set based on the relationship between the amount of heat dissipated by the coolant when the wind passing through the radiator 201 while the vehicle is running and the amount of heat generated by the battery 10 according to the vehicle speed. The relationship between the output, amount of current flow, vehicle speed, and the required dissipable heat quantity is determined in advance through experiments and simulations, and is stored in the ROM of the automatic driving ECU 110 as a required dissipable heat quantity map. This estimation of the required dissipable heat quantity is performed not only when the driving route to the destination is set, but also continuously during automatic driving along the driving route.

[0028] The performance determination unit 304 compares the dissipable heat amount with the required dissipable heat amount. The dissipable heat amount is a value of a vehicle performance parameter and is estimated by the vehicle performance estimation unit 302. The required dissipable heat amount is a value of a required performance parameter and is estimated by the required performance estimation unit 303. Specifically, the comparison between the dissipable heat amount and the required dissipable heat amount is performed at predetermined timings. These predetermined timings are predetermined timings before the start of autonomous driving and during autonomous driving of the vehicle along the driving route. If the value of the vehicle performance parameter is equal to or greater than the value of the required performance parameter at each comparison timing, the performance determination unit 304 determines that the heat dissipation performance of the high-temperature cooling circuit HT is sufficient. In other words, the performance determination unit 304 determines that autonomous driving of the vehicle along the driving route is possible, provided that the heat dissipation performance of other circuits (the refrigerant circuit RE and the battery circuit Bat) is sufficient. In this case, the performance determination unit 304 outputs autonomous driving feasibility information to the autonomous driving feasibility information output unit 306. Upon receiving this automatic driving capability information, the automatic driving capability information output unit 306 outputs command information to the automatic driving control unit 400. This command information is information for implementing automatic driving along the travel route. As a result, a control signal is sent from the automatic driving ECU 110 to the actuator 170, and automatic driving of the vehicle is implemented.

[0029] FIG. 3(a) illustrates an example of the relationship between the estimated dissipable heat quantity and the estimated heat generation amount (e.g., the heat generation amount of the battery 10) when autonomous driving along a driving route is performed. The required dissipable heat quantity is set to be equal to or slightly greater than the estimated heat generation amount. In the heat generation state indicated by the solid line in FIG. 3(a), the estimated dissipable heat quantity (value of the vehicle performance parameter) is equal to or greater than the estimated heat generation amount (corresponding to the estimated required dissipable heat quantity (value of the required performance parameter)). In this case, it is determined that autonomous driving of the vehicle along the driving route is possible, provided that the heat dissipation performance of other circuits (the refrigerant circuit RE and the battery circuit Bat) is sufficiently ensured. Note that in FIG. 3(a), the estimated dissipable heat quantity is constant throughout the driving time. However, in reality, the dissipable heat quantity may change depending on changes in the outside air temperature, vehicle speed, etc. In addition, the performance of each component of the high-temperature cooling circuit HT deteriorates over time. Therefore, as shown in FIG. 3(b), the vehicle performance estimation unit 302 sets a lower heat dissipation capacity (value of the vehicle performance parameter) in accordance with this aging deterioration (see the initial estimated heat dissipation capacity and the estimated heat dissipation capacity after deterioration in FIG. 3(b)). The degree of decrease in the heat dissipation capacity due to aging is determined in advance through experiments and simulations. Furthermore, the performance of each device constituting the high-temperature cooling circuit HT decreases not only due to aging deterioration but also due to malfunction or damage. For example, this occurs when the vehicle experiences a minor collision. The vehicle performance estimation unit 302 sets a decrease in the heat dissipation capacity of the high-temperature cooling circuit HT according to the load at the time of the minor collision. On the other hand, if the value of the vehicle performance parameter is lower than the value of the required performance parameter, the performance determination unit 304 determines that the heat dissipation performance of the high-temperature cooling circuit HT may be insufficient. In other words, even if the heat dissipation performance of other circuits (the refrigerant circuit RE and the battery circuit Bat) is sufficiently ensured, the performance determination unit 304 determines that the vehicle cannot be driven autonomously along the travel route. In other words, it is determined in advance that the heat dissipation performance of the high-temperature cooling circuit HT will be insufficient before the vehicle reaches the destination, making it impossible to continue autonomous driving. In this case, the performance determination unit 304 outputs route resetting instruction information to the route resetting unit 305.

[0030] In the state of the estimated heat generation amount shown by the dashed line in Figure 3(a), there is a period when the estimated dissipable heat amount is less than the estimated heat generation amount. In this case, even if the heat dissipation performance of other circuits (the refrigerant circuit RE and the battery circuit Bat) is sufficiently ensured, it is determined that the vehicle cannot be automatically driven along the travel route.

[0031] The route resetting unit 305 resets the driving route when it receives route resetting instruction information from the performance determining unit 304. In other words, since automatic driving of the vehicle along the original driving route is not possible, the route resetting unit 305 resets the driving route so that automatic driving can be performed along a driving route different from the original driving route. The driving modes of the driving route reset here include detour driving, return driving, and evacuation driving.

[0032] Detour driving is driving in which automatic driving of the vehicle along the original driving route is not possible, but the destination can be reached by changing the driving route (driving along a detour route). In other words, when route resetting unit 305 receives route resetting instruction information from performance determining unit 304, it searches for a detour route to reach the destination and outputs this detour route to vehicle performance estimating unit 302 and required performance estimating unit 303. At this time, vehicle performance estimating unit 302 estimates the amount of heat that can be dissipated (the value of a vehicle performance parameter) assuming that the detour route is traveled. Required performance estimating unit 303 estimates the amount of heat that can be dissipated (the value of a required performance parameter) assuming that the detour route is traveled. Then, performance determining unit 304 compares the amount of heat that can be dissipated (the value of the vehicle performance parameter) with the required amount of heat that can be dissipated (the value of the required performance parameter), and if the value of the vehicle performance parameter is equal to or greater than the value of the required performance parameter, it determines that the destination can be reached by resetting the driving route to the detour route. The performance determination unit 304 then outputs autonomous driving feasibility information to the autonomous driving feasibility information output unit 306. For example, in a situation where the initial driving route has many uphill roads, causing the battery 10 to generate a large amount of heat and the heat dissipation performance of the high-temperature cooling circuit HT to be insufficient, it is assumed that the vehicle will travel along a detour route with many flat roads. This is because it is assumed that traveling along the detour route will reduce the amount of heat generated by the battery 10 and ensure sufficient heat dissipation performance of the high-temperature cooling circuit HT. The autonomous driving feasibility information output unit 306, which has received the autonomous driving feasibility information, then outputs command information to the autonomous driving control unit 400 to perform autonomous driving along the detour route. As a result, a control signal is sent from the autonomous driving ECU 110 to the actuator 170, and the vehicle will be driven autonomously (traveling along the detour route). Furthermore, even while traveling along this detour route, the amount of heat that can be dissipated (the value of the vehicle performance parameter) is compared with the amount of heat that can be dissipated (the value of the required performance parameter), and if it is estimated that the value of the vehicle performance parameter will be less than the value of the required performance parameter (for example, if the amount of heat that can be dissipated decreases due to an increase in outside air temperature), traveling along the detour route will be stopped.

[0033] Return driving is driving to return the vehicle to, for example, a repair shop for maintenance of the high-temperature cooling circuit HT. If the vehicle is unable to drive autonomously along the original driving route, this is due to insufficient heat dissipation performance of the high-temperature cooling circuit HT, and deterioration or failure of the high-temperature cooling circuit HT is expected. For this reason, the vehicle must be returned to a repair shop for maintenance of the high-temperature cooling circuit HT. When route resetting instruction information is received from the performance determination unit 304, when the detour route cannot be found, or when a detour route that ensures the heat dissipation performance of the high-temperature cooling circuit HT cannot be set, the route resetting unit 305 searches for a return route to reach the return point of the repair shop or the like, and outputs this return route to the vehicle performance estimation unit 302 and the required performance estimation unit 303. At this time, the vehicle performance estimation unit 302 estimates the amount of heat that can be dissipated (value of a vehicle performance parameter) if the vehicle were to travel along this return route. The required performance estimation unit 303 estimates the amount of heat that can be dissipated (value of a required performance parameter) if the vehicle were to travel along this return route. Then, the performance determination unit 304 compares the amount of heat that can be dissipated (the value of the vehicle performance parameter) with the amount of heat that can be dissipated (the value of the required performance parameter), and if the value of the vehicle performance parameter is equal to or greater than the value of the required performance parameter, it determines that it is possible to reach the return point by resetting the return route as the driving route. Then, the performance determination unit 304 outputs automatic driving feasibility information to the automatic driving feasibility information output unit 306. Having received the automatic driving feasibility information, the automatic driving feasibility information output unit 306 outputs command information to the automatic driving control unit 400 for performing automatic driving along the return route. As a result, a control signal is sent from the automatic driving ECU 110 to the actuator 170, and automatic driving of the vehicle (driving along the return route) is performed. Note that even during driving along this return route, the amount of heat that can be dissipated (the value of the vehicle performance parameter) is compared with the amount of heat that can be dissipated that is required (the value of the required performance parameter), and if it is estimated that the value of the vehicle performance parameter will be less than the value of the required performance parameter (for example, if the amount of heat that can be dissipated decreases due to an increase in outside air temperature), driving along the return route is stopped.

[0034] If it is estimated that the value of the vehicle performance parameter will be less than the value of the required performance parameter in both the detour driving and the return driving, the route resetting unit 305 determines that the detour driving and the return driving are impossible. In this case, evacuation driving is performed. That is, the performance determination unit 304 outputs evacuation driving information to the autonomous driving feasibility information output unit 306. The autonomous driving feasibility information output unit 306, which has received the evacuation driving information, outputs command information to the autonomous driving control unit 400 to perform evacuation driving. As a result, a control signal is sent from the autonomous driving ECU 110 to the actuator 170, which controls the vehicle to drive to the shoulder of the road by evacuation driving and then stop the vehicle. In this case, rescue request information is sent by the external communication device 130, and the vehicle waits for the arrival of a rescue vehicle.

[0035] Next, the procedure of the autonomous driving feasibility determination process performed by the autonomous driving feasibility determination unit 300 will be described with reference to the flowchart in FIG. 4. This flowchart is executed when a driving route (driving route to a destination) is set by the navigation device 160, and when autonomous driving of the vehicle along the driving route is started, and during the execution of the autonomous driving. Note that here, too, an example will be described in which whether to start or continue autonomous driving is determined depending on whether the heat dissipation performance of the high-temperature cooling circuit HT is sufficiently ensured. First, in step ST1, various information used for the autonomous driving feasibility determination is acquired. For example, information such as the detected coolant flow rate, coolant temperature, vehicle speed, rotation speed of the electric radiator fan 202, and outside air temperature is acquired. In addition, information such as output, power supply amount, and vehicle speed at each point on the driving route is acquired. In step ST2, the vehicle performance estimation unit 302 estimates the dissipable heat amount (value of a vehicle performance parameter). In addition, the required performance estimation unit 303 estimates the required dissipable heat amount (value of a required performance parameter). The procedure then proceeds to step ST3, where it is determined whether the amount of heat that can be dissipated is equal to or greater than the required amount of heat that can be dissipated. If the determination in step ST3 is YES, the procedure proceeds to step ST4, where it is determined that the heat dissipation performance of the high-temperature cooling circuit HT is sufficiently ensured. Then, on the condition that the heat dissipation performance of the other circuits (the refrigerant circuit RE and the battery circuit Bat) is sufficiently ensured, the vehicle is automatically driven along the driving route. If the determination in step ST3 is NO, the procedure proceeds to step ST5, where it is determined whether a detour route has been set as the driving route. That is, it is determined whether the amount of heat that can be dissipated assuming that the vehicle traveled along the detour route searched by the route resetting unit 305 is equal to or greater than the required amount of heat that can be dissipated. If the determination in step ST5 is YES, the procedure proceeds to step ST4, where the vehicle is automatically driven along the detour route. If the determination in step ST5 is NO, the procedure proceeds to step ST6, where it is determined whether a return route has been set as the driving route.In other words, the route resetting unit 305 determines whether the return route has been reset as the driving route based on whether the amount of heat that can be dissipated if the vehicle were to travel along the return route found is equal to or greater than the required amount of heat that can be dissipated. If the determination in step ST6 is YES, the process proceeds to step ST4, and the vehicle is automatically driven along the return route. If the determination in step ST6 is NO, it is estimated that the values ​​of the vehicle performance parameters are less than the values ​​of the required performance parameters in both the detour driving and the return driving. Therefore, since neither the detour driving nor the return driving can be performed, the vehicle is driven to an evacuation position in step ST7. The above operations are repeated.

[0036] -Effects of the embodiment- As described above, in this embodiment, when it is estimated that the value of the vehicle performance parameter will be less than the value of the required performance parameter, the automated driving of the vehicle along the planned driving route is not performed. Specifically, one of detour driving, return driving, and evacuation driving is performed. This allows for early determination of when automated driving along the predetermined driving route will be impossible.

[0037] -Variations- Next, a modified example will be described. In the above-described embodiment, when the value of the vehicle performance parameter is less than the value of the required performance parameter, one of detour driving, return driving, and evacuation driving is automatically set. In this modified example, instead, candidate driving conditions for when the value of the vehicle performance parameter is less than the value of the required performance parameter are presented to the user, and automatic driving is performed under a driving condition selected by the user from these candidate driving conditions. FIG. 5 is a block diagram showing a schematic configuration of an automatic driving system 100 mounted on a vehicle according to this modified example. In FIG. 5, the same functional units as those described in FIG. 1 in the above-described embodiment are assigned the same reference numerals, and their description will be omitted.

[0038] As shown in FIG. 5, the autonomous driving system 100 mounted on the vehicle according to this modification includes a driving condition presentation unit 308. When the driving condition presentation unit 308 receives route resetting instruction information from the performance determination unit 304, it calculates driving conditions under which the values ​​of the vehicle performance parameters are equal to or greater than the values ​​of the required performance parameters, and presents the driving conditions to the vehicle user. Examples of a means for presenting the driving conditions include displaying the driving conditions on the display. For example, one or more detour routes or one or more return routes may be presented. Alternatively, information for changing the vehicle speed or estimated arrival time without changing the driving route may be presented. This allows the vehicle user to arbitrarily set the vehicle driving conditions.

[0039] - Redundant design example - Next, several examples of redundant designs for the high-temperature cooling circuit HT to prevent the heat dissipation performance of the high-temperature cooling circuit HT from becoming insufficient will be described. When the components in the following Figures 6(a) to 6(e) are the same as the components of the high-temperature cooling circuit HT described using Figure 2(b) in the above embodiment, the same reference numerals are used and their description will be omitted.

[0040] FIG. 6(a) shows two water pumps 203a and 203b connected in parallel. In this case, even if one water pump 203a fails, the other water pump 203b can operate to circulate the coolant. In this case, the heat dissipation performance of the high-temperature cooling circuit HT is reduced by approximately half. However, even if the heat dissipation performance is reduced in this manner, it is possible to determine that the vehicle is capable of autonomous driving along the travel route as long as the vehicle performance parameters are equal to or greater than the required performance parameters. Therefore, autonomous vehicle driving is possible. FIG. 6(b) shows two electric radiator fans 202a and 202b connected in parallel. In this case, even if one electric radiator fan 202a fails, the other electric radiator fan 202b can operate to blow air to the radiator 201. In this case, the heat dissipation performance of the high-temperature cooling circuit HT is reduced by approximately half. However, even if the heat dissipation performance is reduced in this manner, it is possible to determine that the vehicle is capable of autonomous driving along the travel route as long as the vehicle performance parameters are equal to or greater than the required performance parameters. Therefore, it is possible to perform automatic driving of the vehicle. FIG. 6(c) shows three radiators 201a, 201b, and 201c connected in series. In this case, even if one radiator 201a is damaged, heat exchange is possible using the other two radiators 201b and 201c. In this case, the heat dissipation performance of the high-temperature cooling circuit HT is reduced to approximately two-thirds. However, even if the heat dissipation performance is reduced in this way, it is possible to determine that automatic driving of the vehicle along the travel route is possible as long as the vehicle performance parameter value is equal to or greater than the required performance parameter value. Therefore, it is possible to perform automatic driving of the vehicle. FIG. 6(d) shows three radiators 201a, 201b, and 201c connected in parallel. In this case, even if one radiator 201a is damaged, heat exchange is possible using the other two radiators 201b and 201c.In this case, the heat dissipation performance of the high-temperature cooling circuit HT will be reduced to approximately two-thirds. However, even in this case, as long as the vehicle performance parameters are equal to or greater than the required performance parameters, it is possible to determine that the vehicle is capable of autonomous driving along the travel route, and autonomous driving of the vehicle can be implemented. Valves are provided upstream and downstream of each radiator 201a, 201b, and 201c. Closing these valves prevents coolant from flowing through the damaged radiator. Figure 6(e) shows a configuration that allows heat exchange with other cooling circuits to compensate for the insufficient heat dissipation performance of the high-temperature cooling circuit HT. Examples of other cooling circuits include a PCU (Power Control Unit) cooling circuit 500. The PCU cooling circuit 500 circulates coolant. The PCU cooling circuit 500 is a circulation circuit. This circulation circuit is composed of a radiator 501, a water pump 502, and a PCU cooling unit 503, all connected by piping. The radiator 501 is disposed opposite the radiator 201 of the high-temperature cooling circuit HT. The radiator 501 dissipates heat from the coolant outside the vehicle. A water pump 502 circulates the coolant within the PCU cooling circuit 500. A PCU cooling unit 503 exchanges heat between the coolant circulating through the PCU cooling circuit 500 and the PCU. This heat exchange cools the PCU. A heat exchanger 504 enables heat exchange between the coolant circulating through the high-temperature cooling circuit HT and the coolant circulating through the PCU cooling circuit 500. Therefore, when the heat dissipation performance of the high-temperature cooling circuit HT is insufficient, the heat of the coolant in the high-temperature cooling circuit HT is dissipated to the coolant in the PCU cooling circuit 500. This heat dissipation overcomes the insufficient heat dissipation performance of the high-temperature cooling circuit HT. This makes it possible to resolve situations in which the values ​​of the vehicle performance parameters are lower than the values ​​of the required performance parameters. The redundant design example described above can be applied not only to the high-temperature cooling circuit HT, but also to the refrigerant circuit RE and the battery circuit Bat.

[0041] -Other embodiments- The present invention is not limited to the above-described embodiment and modified examples, and all modifications and applications that fall within the scope of the claims and equivalents thereto are possible.

[0042] For example, in the above embodiment and modified example, the heat dissipation performance of the battery cooling system 200 was used as an example of vehicle performance used to determine whether autonomous driving is possible. However, the present invention is not limited to this, and the heat dissipation performance of the cooling systems of various motors may also be used. Furthermore, the hydraulic pressure supply performance of a hydraulic system or the power supply performance of an electrical system mounted on the vehicle may also be used. [Industrial Applicability]

[0043] The present invention is applicable to an automated driving system. [Explanation of symbols]

[0044] 100...Automatic driving system 302...Vehicle performance estimation unit 303...Required performance estimation unit 305... Route resetting unit 308... Driving condition presentation unit 400... Automatic driving control unit

Claims

1. In an automated driving system that controls the automated driving of a vehicle along a predetermined driving route, a vehicle performance estimation unit that estimates values ​​of vehicle performance parameters correlated with vehicle performance used to determine whether or not autonomous driving is possible when autonomous driving of the vehicle along the planned travel route is performed, at least either before the autonomous driving starts or during the autonomous driving along the travel route; and a required performance estimation unit that estimates a value of a required performance parameter that is correlated with a vehicle performance required for performing automatic driving of the vehicle along the planned travel route; an autonomous driving control unit that performs autonomous driving of the vehicle along the planned driving route on condition that the value of the vehicle performance parameter is equal to or greater than the value of the required performance parameter, and that does not perform autonomous driving of the vehicle along the planned driving route when the value of the vehicle performance parameter is less than the value of the required performance parameter, An autonomous driving system characterized in that, when a minor collision occurs to the vehicle, the vehicle performance estimation unit sets a reduction amount to lower the estimated value of the vehicle performance parameter value depending on the load of the minor collision.

2. 2. The automated driving system according to claim 1, The vehicle performance used to determine whether autonomous driving is possible is the heat dissipation performance of a cooling system that is mounted on the vehicle and dissipates heat from a heat-generating device, the vehicle performance parameter is a heat dissipation amount of the cooling system when the vehicle is automatically driven along the planned travel route, An autonomous driving system characterized in that the required performance parameter is the required heat dissipation amount of the cooling system that exceeds the heat generation amount of the device when autonomous driving of the vehicle is performed along the planned driving route.

3. In the automatic driving system according to claim 1 or 2, An autonomous driving system characterized in that the vehicle performance estimation unit sets the estimated value of the vehicle performance parameter lower in accordance with the deterioration over time of the vehicle performance used to determine whether autonomous driving is possible.

4. In the automatic driving system according to claim 1 or 2, An autonomous driving system characterized by having a route resetting unit that, when the value of the vehicle performance parameter is less than the value of the required performance parameter, sets a driving route different from the planned driving route, where the value of the vehicle performance parameter is greater than or equal to the value of the required performance parameter, as a driving route to be controlled by the autonomous driving of the vehicle.

5. In the automatic driving system according to claim 1 or 2, An autonomous driving system characterized by having a driving condition presentation unit that, when the value of the vehicle performance parameter is less than the value of the required performance parameter, presents to the vehicle user driving conditions that are different from the driving conditions of the planned driving route and in which the value of the vehicle performance parameter is greater than or equal to the value of the required performance parameter.

Images