vehicle

Abstract

To provide a vehicle configured so that a temperature of a friction brake device can be suppressed from rising.SOLUTION: A vehicle 10 is provided with: a temperature predicting part 731 that predicts a temperature of a friction brake device 40 when the vehicle travels on a section in which brakes are used frequently; a motor control part 722 that controls a motor generator 21; and a battery control part 710 that controls a battery 30. The motor control part 722 restricts regenerative operation of the motor generator 21 on the basis of the fact that an SOC value of the battery 30 reaches an upper limit value. When it is predicted that a temperature of the friction brake device 40 becomes a predetermined temperature or higher, the battery control part 710 lowers the SOC value of the battery 30 before the vehicle 10 reaches the section in which brakes are used frequently.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to vehicles. [Background technology]

[0002] A conventional vehicle control device is described in Patent Document 1. This control device switches from regenerative braking to friction braking when the vehicle enters a braking state while the state of charge of the battery mounted on the vehicle is equal to or higher than a predetermined value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4561212 Summary of the Invention [Problem to be solved by the invention]

[0004] A vehicle control device such as that described in Patent Document 1 uses friction braking instead of regenerative braking when the battery's state of charge is above a predetermined value, increasing the proportion of friction braking used. Therefore, if the frequency of friction braking increases in sections where braking is frequent, such as when a vehicle is traveling down a long slope, the temperature of the friction brake device is likely to rise. If the temperature of the friction brake device rises excessively, the brake fluid may boil, making the brakes less effective, potentially resulting in a phenomenon known as vapor lock. Since electric vehicles do not have engine brakes, there is a particular concern that vapor lock is more likely to occur.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a vehicle that is capable of suppressing an increase in temperature of a friction brake device. [Means for solving the problem]

[0006] A vehicle (10) that solves the above problem includes a friction brake device (40) that applies a braking force based on friction force to the vehicle, a rotating electric machine (21) that applies a braking force based on regenerative torque to the vehicle, and a battery (30) that stores electric power generated by the regenerative operation of the rotating electric machine. The vehicle includes a temperature prediction unit (731) that predicts the temperature of the friction brake device when the vehicle travels a predetermined section, a rotating electric machine control unit (722) that controls the rotating electric machine, and a battery control unit (710) that controls the battery. The rotating electric machine control unit limits the regenerative operation of the rotating electric machine based on the battery's state of charge reaching a predetermined upper limit. If the temperature of the friction brake device is predicted to exceed the predetermined temperature, the battery control unit reduces the state of charge of the battery before the vehicle reaches the predetermined section.

[0007] With this configuration, the battery's state of charge decreases before the vehicle reaches the specified section, so even if the rotating electric machine performs regenerative operation when the vehicle actually travels the specified section, the battery's state of charge is less likely to reach the specified upper limit. As a result, the rotating electric machine is more likely to continue regenerative operation, which reduces the burden on the friction brake device. Therefore, it is possible to suppress the temperature rise of the friction brake device.

[0008] The symbols in parentheses in the above means and claims are examples showing the correspondence with specific means described in the embodiments to be described later. [Effects of the Invention]

[0009] According to the vehicle of the present disclosure, it is possible to suppress the temperature rise of the friction brake device. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a vehicle according to the first embodiment. [Figure 2] FIG. 2 is a block diagram showing a schematic configuration of the vehicle according to the first embodiment. [Figure 3]FIG. 3 is a flowchart showing the procedure of processing executed by the ECU of the first embodiment. [Figure 4] 4(A) to 4(C) are timing charts showing the transition of the SOC value of the battery, the braking torque of each of the motor generator and the friction brake device, and the temperature of the friction brake device in the first embodiment. [Figure 5] FIG. 5 is a flowchart showing the procedure of processing executed by the ECU of the second embodiment. [Figure 6] FIG. 6 is a flowchart showing the procedure of processing executed by the ECU of the third embodiment. [Figure 7] FIG. 7 is a flowchart showing the procedure of processing executed by the ECU of the fourth embodiment. [Figure 8] FIG. 8 is a flowchart showing the procedure of processing executed by the ECU of the fifth embodiment. [Figure 9] 9(A) to 9(C) are timing charts showing the transition of the SOC value of the battery, the braking torque of each of the motor generator and the friction brake device, and the temperature of each of the friction brake device and power train equipment in the fifth embodiment. [Figure 10] FIG. 10 is a flowchart showing the procedure of processing executed by the ECU of the sixth embodiment. [Figure 11] FIG. 11 is a flowchart showing the procedure of processing executed by an ECU in a modified example of the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of a vehicle will be described with reference to the drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicate descriptions will be omitted. First Embodiment First, a schematic configuration of a vehicle 10 according to the first embodiment will be described, as shown in Fig. 1. As shown in Fig. 1, the vehicle 10 includes a motor generator 21, a power transmission mechanism 22, an inverter device 23, a battery 30, accessories 31, and a friction brake device 40. The vehicle 10 according to this embodiment is a so-called electric vehicle that runs using the motor generator 21 as a power source.

[0012] The power transmission mechanism 22 is a mechanism that transmits the power output from the motor generator 21 to the wheels 12 via the drive shaft 11. The power transmission mechanism 22 includes, for example, a transmission, a transaxle, and the like. The inverter device 23 converts the DC power stored in the battery 30 into three-phase AC power, and supplies the converted three-phase AC power to the motor generator 21.

[0013] The motor generator 21 operates as both an electric motor and a generator. When operating as an electric motor, the motor generator 21 is driven by three-phase AC power supplied from the inverter device 23. The driving force of the motor generator 21 is transmitted to the wheels 12 via the power transmission mechanism 22, causing the wheels 12 to rotate and the vehicle 10 to travel. In this embodiment, the motor generator 21 corresponds to a rotating electric machine.

[0014] Motor generator 21 operates as a generator when braking vehicle 10. Specifically, when braking vehicle 10, motor generator 21 performs a regenerative operation. As a result, braking torque generated in motor generator 21 is applied to wheels 12 via power transmission mechanism 22, thereby applying a braking force to vehicle 10. In addition, three-phase AC power generated by the regenerative operation of motor generator 21 is converted into DC power by inverter device 23 and charged into battery 30.

[0015] In this embodiment, the motor generator 21, the power transmission mechanism 22, and the inverter device 23 correspond to the power train device 20. The accessories 31 are devices that are driven by the power supplied from the battery 30, excluding devices such as the motor generator 21 that are necessary for running the vehicle 10. The accessories 31 include, for example, an air conditioner, a light device, a wiper device, etc. In this embodiment, the accessories 31 correspond to electrical loads.

[0016] The friction brake device 40 is a device that applies a braking force to the vehicle 10 by applying a frictional force to a rotating body that rotates integrally with the wheel 12. The friction brake device 40 of this embodiment is a so-called hydraulic brake device that applies a frictional force by bringing brake pads into contact with the rotating body using the hydraulic pressure of brake fluid.

[0017] As shown in FIG. 2, the vehicle 10 further includes a navigation device 51, an imaging device 52, and an on-board sensor 60. The navigation device 51 is a device that provides guidance on the driving route of the vehicle 10. The navigation device 51 has a storage device 510 that stores a map database and the like. The map database stores various information related to the map, such as the length of the road, the gradient of the road, the altitude of each point, and the legal speed limit at each point. For example, when a destination is set by the driver's operation, the navigation device 51 sets a driving route from the current location of the vehicle 10 to the destination and displays the driving route on a display. The navigation device 51 also obtains information such as the amount of road congestion at each point by using VICS (Vehicle Information and Communication System) (registered trademark).

[0018] The imaging device 52 captures an image of the surroundings of the vehicle 10 and generates image data thereof. The imaging device 52 captures an image of, for example, a road sign provided on a road, and generates image data of the captured road sign. The on-vehicle sensors 60 are a general term for sensors mounted on the vehicle 10 to detect various state quantities of the vehicle 10. The on-vehicle sensors 60 include a position sensor 61, an outside air temperature sensor 62, a weight sensor 63, and the like. The position sensor 61 acquires the current location of the vehicle 10 using a GPS (Global Positioning System) or the like. The outside air temperature sensor 62 detects the outside air temperature, which is the temperature outside the vehicle 10. The weight sensor 63 detects, for example, the total weight of cargo in the loading platform of the vehicle 10. Each of the sensors 61 to 63 outputs a signal corresponding to the detected physical quantity.

[0019] The vehicle 10 further includes a battery ECU (Electronic Control Unit) 71, a cruise control ECU 72, and a prediction ECU 73. Each of the ECUs 71 to 73 is configured mainly with a microcomputer having a CPU, ROM, etc. The ECUs 71 to 73 are connected to each other so as to be able to communicate with each other via a network 90 mounted on the vehicle 10. The ECUs 71 to 73 are also connected to the navigation device 51, the imaging device 52, and the in-vehicle sensor 60 so as to be able to communicate with each other via the in-vehicle network 90. ​​This allows the ECUs 71 to 73 to acquire map information from the navigation device 51 and image data from the imaging device 52 via the in-vehicle network 90. ​​In this embodiment, the ECUs 71 to 73 correspond to control devices.

[0020] The battery ECU 71 controls the battery 30. The battery ECU 71 includes a battery control unit 710 as a functional configuration realized by the CPU executing a program stored in the ROM. The battery control unit 710 monitors the state of the battery 30. The battery control unit 710 receives an output signal from a battery state sensor 64. The battery state sensor 64 detects state quantities of the battery 30, such as a SOC (State Of Charge) value and temperature. The SOC value represents the state of charge of the battery 30 in a range from 0% to 100%, with a completely discharged state of the battery 30 defined as 0% and a fully charged state of the battery 30 defined as 100%. In this embodiment, the SOC value corresponds to the state of charge.

[0021] The battery control unit 710 acquires information about the SOC value and temperature of the battery 30 based on the output signal of the battery state sensor 64, and monitors the state of charge of the battery 30 based on the acquired SOC value and temperature. For example, when the SOC value of the battery 30 reaches a predetermined upper limit SOCmax due to the regenerative operation of the motor generator 21, the battery control unit 710 transmits a regeneration restriction command to the cruise control ECU 72 to request the cruise control ECU 72 to restrict the regenerative operation of the motor generator 21. This prevents the battery 30 from being charged to a value equal to or greater than the predetermined upper limit SOCmax, thereby preventing malfunctions in the battery 30. The battery control unit 710 also transmits a regeneration restriction command to the cruise control ECU 72 when the temperature of the battery 30 reaches a predetermined upper limit temperature. Furthermore, after temporarily transmitting a regeneration restriction command to the cruise control ECU 72, if the SOC value of the battery 30 becomes less than a predetermined upper limit value SOCmax and the temperature of the battery 30 becomes less than a predetermined upper limit temperature, the battery control unit 710 transmits a regeneration restriction release command to the cruise control ECU 72. In this embodiment, the SOC value of the battery 30 reaching the upper limit value SOCmax corresponds to the state of charge of the battery 30 reaching a predetermined upper limit state.

[0022] In addition, the battery control unit 710 of this embodiment can forcibly drive or stop the auxiliary equipment 31 by sending a command signal to the auxiliary equipment 31 via the in-vehicle network 90. The driving control ECU 72 controls the driving of the vehicle 10. The driving control ECU 72 includes a driving torque calculation unit 720, a braking torque calculation unit 721, a motor control unit 722, and a brake control unit 723 as functional components realized by the CPU executing a program stored in the ROM.

[0023] The running torque calculation unit 720 calculates a running torque command value according to the amount of depression of the accelerator pedal of the vehicle 10 using an arithmetic expression, a map, etc., and transmits the calculated running torque command value to the motor control unit 722. The braking torque calculation unit 721 calculates a final braking torque command value Tb* according to the amount of depression of the brake pedal of the vehicle 10 using an arithmetic expression, a map, etc. The braking torque calculation unit 721 sets a first braking torque command value Tb1* and a second braking torque command value Tb2* from the final braking torque command value Tb*. The first braking torque command value Tb1* is a target value of the braking torque to be generated by the motor generator 21. The second braking torque command value Tb2* is a target value of the braking torque to be generated by the friction brake device 40.

[0024] When realizing the braking torque corresponding to the final braking torque command value Tb*, the braking torque calculation unit 721 preferentially uses the braking torque of the motor generator 21 and compensates for any shortfall in the braking torque of the motor generator 21 with the braking torque of the friction brake device 40. For example, the braking torque calculation unit 721 acquires information on the SOC value and temperature of the battery 30 from the battery ECU 71 and sets an upper limit value Tb1max* of the first braking torque command value based on the acquired SOC value and temperature of the battery 30. When the final braking torque command value Tb* is equal to or less than the upper limit value Tb1max* of the first braking torque command value, the braking torque calculation unit 721 sets the first braking torque command value Tb1* to the final braking torque command value Tb* and sets the second braking torque command value Tb2* to "0". Furthermore, when the final braking torque command value Tb* exceeds the upper limit value Tb1max* of the first braking torque command value, the braking torque calculation unit 721 sets the first braking torque command value Tb1* to the final braking torque command value Tb* and sets the second braking torque command value Tb2* to "Tb*-Tb1max*". Furthermore, when the braking torque calculation unit 721 receives a regeneration restriction command transmitted from the battery ECU 71, the braking torque calculation unit 721 sets the first braking torque command value Tb1* to "0" and sets the second braking torque command value Tb2* to the final braking torque command value Tb* for a period until it subsequently receives a regeneration restriction release command transmitted from the braking torque calculation unit 721. The braking torque calculation unit 721 transmits the first braking torque command value Tb1* calculated in this manner to the motor control unit 722 and transmits the second braking torque command value Tb2* to the brake control unit 723.

[0025] When the motor control unit 722 receives a traveling torque command value transmitted from the traveling torque calculation unit 720, it drives the motor generator 21 so that torque corresponding to the traveling torque command value is output from the motor generator 21. Furthermore, when the motor control unit 722 receives a first braking torque command value Tb1* transmitted from the braking torque calculation unit 721, it causes the motor generator 21 to perform a regenerative operation so that braking torque corresponding to the first braking torque command value Tb1* is output from the motor generator 21. In this embodiment, the motor control unit 722 corresponds to a rotating electric machine control unit.

[0026] When the brake control unit 723 receives the second braking torque command value Tb2* transmitted from the braking torque calculation unit 721, it controls the friction brake device 40 so that a braking torque corresponding to the second braking torque command value Tb2* is applied from the friction brake device 40 to the wheel 12. In such a vehicle 10, for example, if the driver frequently applies the brakes while the vehicle 10 is traveling downhill, the motor generator 21 will perform regenerative braking multiple times. This increases the SOC value of the battery 30. When the SOC value of the battery 30 reaches an upper limit SOCmax, the regenerative operation of the motor generator 21 is restricted, and braking of the vehicle 10 is performed solely by the friction brake device 40. If this situation continues, there is a possibility that the temperature of the friction brake device 40 will rise sharply. As a result, if the temperature of the brake fluid in the friction brake device 40 rises, the brake fluid may boil, making it difficult to brake, which may result in a so-called vapor lock phenomenon.

[0027] Therefore, in this embodiment, the vehicle 10 predicts whether a future travel route from the present onward includes a high-braking section where braking is frequently performed. If a high-braking section is predicted, the SOC value of the battery 30 is reduced by forcibly driving the auxiliary equipment 31 before the vehicle 10 reaches the high-braking section. A state in which braking is frequently performed refers to a state in which braking is performed more frequently than when the vehicle 10 is traveling on a flat road, for example. The auxiliary equipment 31 subject to the forcible driving is predetermined, and includes, for example, an air conditioning compressor, a coolant pump, a radiator fan, etc. By reducing the SOC value of the battery 30, even if the motor-generator 21 performs regenerative operation in the high-braking section, the SOC value of the battery 30 is less likely to reach the upper limit SOCmax. This prevents the regenerative operation of the motor-generator 21 from being limited in the high-braking section. In other words, the motor-generator 21 and the friction brake device 40 can be used together, thereby suppressing a temperature rise in the friction brake device 40. In this embodiment, the heavy braking section corresponds to the predetermined section.

[0028] The configuration for suppressing the temperature rise of the friction brake device 40 in the heavy braking section will be specifically described below. The prediction ECU 73 executes various prediction processes. The prediction ECU 73 includes a section prediction unit 730 and a temperature prediction unit 731 as functional components realized by the CPU executing a program stored in the ROM. The section prediction unit 730 predicts a heavy braking section. When the section prediction unit 730 predicts the existence of a heavy braking section, the temperature prediction unit 731 determines whether or not there is a possibility that the friction brake device 40 will become hot in the heavy braking section.

[0029] Next, with reference to FIG. 3, a procedure for the process executed by the ECUs 71 to 73 to suppress a temperature rise in the friction brake device 40 will be specifically described. As shown in Fig. 3, the section prediction unit 730 first predicts a section where braking is required frequently as part of the processing in step S10. For example, when the driver operates the navigation device 51 to set a driving route for the vehicle 10, the section prediction unit 730 acquires road information for that driving route from the navigation device 51. The road information includes, for example, information on the altitude and gradient at each point on the driving route, information on downhill sections with gradients equal to or greater than a predetermined value, the amount of road congestion at each point, etc. If the section prediction unit 730 finds a downhill section that satisfies both of the following conditions (a1) and (a2) based on the acquired road information, it determines that the section is a section where braking is required frequently.

[0030] (a1) The average gradient of the downhill section exceeds a predetermined value. (a2) The length of the downhill section that satisfies (a1) is equal to or greater than a predetermined length. Alternatively, if there is a section that satisfies both of the following conditions (b1) and (b2) based on the road information, the section prediction unit 730 determines that the section is a heavy braking section.

[0031] (b1) The average gradient of the downhill section exceeds a predetermined value. (b2) The average congestion volume of the road in the downhill section that satisfies (a1) exceeds a predetermined value. In addition, when the road is congested, the driver frequently applies the brakes to avoid contact with other vehicles. Therefore, in this embodiment, the amount of road congestion is used as one of the conditions for determining whether the section is a section where braking is frequently used.

[0032] In step S11, which follows step S10, the section prediction unit 730 determines whether or not a heavy braking section exists on the travel route of the vehicle 10. If a downhill section that satisfies both the above conditions (a1) and (a2) exists, or if a downhill section that satisfies both the above conditions (b1) and (b2) exists, the section prediction unit 730 determines that a heavy braking section exists. In this case, the section prediction unit 730 makes a positive determination in the process of step S11. At this time, the section prediction unit 730 transmits to the temperature prediction unit 731 information that a heavy braking section exists, as well as information on the average gradient and length of the heavy braking section.

[0033] If the section prediction unit 730 makes a positive determination in the processing of step S11, the temperature prediction unit 731 determines in the processing of step S12 whether or not there is a possibility that the friction brake device 40 will reach a high temperature state in the heavy braking section. Note that a high temperature state refers to a state in which there is a possibility that the brake fluid will boil. Specifically, if the heavy braking section satisfies both of the following conditions (c1) and (c2), the temperature prediction unit 731 determines that there is a possibility that the friction brake device 40 will reach a high temperature state of a predetermined temperature or higher in the heavy braking section.

[0034] (c1) The length of the section where braking is frequently used exceeds the specified length. (c2) The average gradient of the section where braking is frequently used exceeds a specified value. The predetermined values ​​set for the average gradients used in the above conditions (a1), (b1), and (c2) may be different or the same value. The same applies to the predetermined lengths used in the above conditions (a2) and (c1).

[0035] If the temperature prediction unit 731 determines that there is a possibility that the friction brake device 40 will become overheated in the heavy braking section, it makes a positive determination in the processing of step S12. In this case, the temperature prediction unit 731 sets a target SOC value for the battery 30 at the start point of the heavy braking section and transmits information about the start point of the heavy braking section and the target SOC value to the battery control unit 710. The target SOC value is a target SOC value that the battery 30 needs to have at the start point of the heavy braking section so that the SOC value of the battery 30 will not reach the upper limit value SOCmax even if the motor generator 21 performs regenerative operation in the section from the start point to the end point of the heavy braking section. In other words, if the SOC value of the battery 30 at the start point of the heavy braking section is equal to or less than the target SOC value, it can be estimated that the SOC value of the battery 30 will not reach the upper limit value SOCmax at the end point of the heavy braking section. Note that the target SOC value may be a fixed value or a variable value. When the target SOC value is a variable value, the temperature prediction unit 731 sets the target SOC value using, for example, an arithmetic expression or a map based on the length of the heavy braking section or the average gradient. In this embodiment, the target SOC value corresponds to the target state of charge of the battery 30.

[0036] The battery control unit 710 executes an SOC adjustment process as the process of step S13 following step S12. In this embodiment, the amount of power consumed per unit time when one or more auxiliary devices 31 that are the subject of forced drive are driven is determined in advance through experiments or the like, and information on the amount of power consumed per unit time is stored in advance in the ROM of the battery ECU 71. While the vehicle 10 is traveling toward the destination, the battery control unit 710 monitors the transition of the current SOC value of the battery 30 and calculates the time required to reduce the SOC value of the battery 30 to the target SOC value from the start of forced drive of the auxiliary devices 31 by subtracting the target SOC value from the current SOC value and dividing the result by the amount of power consumed per unit time of the auxiliary devices 31. Based on the calculated time and information such as the legal speed limit of the road, the battery control unit 710 calculates a required mileage, which is the mileage required to reduce the SOC value of the battery 30 to the target SOC value, and sets a point that is the required mileage before the start of the braking-heavy section as the SOC adjustment start point. Then, when the battery control unit 710 determines that the current location of the vehicle 10 has reached the SOC adjustment start point, it forcibly drives the auxiliary machines 31 that are the target of forcible driving. The battery control unit 710 continues forcibly driving the auxiliary machines 31 until the vehicle 10 reaches the start point of the heavy braking section. After the battery control unit 710 executes the process of step S13, the process shown in FIG. 3 ends.

[0037] On the other hand, if the interval prediction unit 730 makes a negative determination in the process of step S11, or if the temperature prediction unit 731 makes a negative determination in the process of step S12, the process shown in FIG. 3 also ends. Next, an example of the operation of the vehicle 10 of this embodiment will be described.

[0038] As shown in Fig. 4, when the vehicle 10 reaches the SOC adjustment start point at time t10, the auxiliary equipment 31 is forced to be driven. As a result, as shown in Fig. 4(A), the SOC value of the battery 30 gradually decreases from time t10 to time t11. Time t11 is the time when the vehicle 10 reaches the start point of the heavy braking section. At time t11, the SOC value of the battery 30 decreases to the target SOC value.

[0039] When vehicle 10 reaches the start point of the heavy braking section at time t11, the driver begins braking, causing motor generator 21 to perform regenerative operation and friction brake device 40 to operate. The regenerative operation of motor generator 21 generates a braking torque as shown by the solid line in FIG. 4(B), and the operation of friction brake device 40 generates a braking torque as shown by the dashed line in FIG. 4(B). Furthermore, since motor generator 21 performs regenerative operation after time t11, the SOC value of battery 30 gradually increases from the target SOC value, as shown in FIG. 4(A). Furthermore, as shown in FIG. 4(C), the temperature TBR of friction brake device 40 gradually increases after time t11.

[0040] Because the SOC value of the battery 30 has fallen to the target SOC value at time t11, even if the regenerative operation of the motor generator 21 continues from time t11 to time t12, the SOC value of the battery 30 will not reach the upper limit value SOCmax at time t12. Time t12 is the time when the vehicle 10 reaches the end point of the heavy braking section. As shown in Figure 4(C) , a sudden rise in the temperature TBR of the friction brake device 40 can be suppressed from time t11 to time t12, and therefore the temperature TBR of the friction brake device 40 can be prevented from reaching the upper limit temperature at which an abnormality may occur.

[0041] According to the vehicle 10 of the present embodiment described above, the following actions and effects (1) to (6) can be obtained. (1) The prediction ECU 73 includes a temperature prediction unit 731 that predicts the temperature of the friction brake device 40 when the vehicle 10 travels through a braking-heavy section. The cruise control ECU 72 includes a motor control unit 722 that controls the motor generator 21. The battery ECU 71 includes a battery control unit 710 that controls the battery 30. The motor control unit 722 limits the regenerative operation of the motor generator 21 when the SOC value of the battery 30 reaches an upper limit value SOCmax. If the battery control unit 710 predicts that the friction brake device 40 will reach a high temperature equal to or higher than a predetermined temperature in the braking-heavy section, it reduces the SOC value of the battery 30 before the vehicle 10 reaches the braking-heavy section. This configuration makes it easier for the motor generator 21 to continue regenerative operation in the braking-heavy section, thereby reducing the burden on the friction brake device 40. This makes it possible to suppress a rise in temperature of the friction brake device 40.

[0042] (2) The prediction ECU 73 further includes a section prediction unit 730. The section prediction unit 730 predicts a braking-heavy section where braking is frequently performed on the future travel route of the vehicle 10. In this way, by including a configuration for predicting a braking-heavy section, it becomes possible to more appropriately predict a section where the temperature of the friction brake device 40 will rise.

[0043] (3) As shown in (b2) above, the section prediction unit 730 predicts sections where braking is frequently required based on congestion information on the future travel route of the vehicle 10. This configuration makes it possible to predict sections where braking is frequently required with higher accuracy. (4) When the SOC adjustment start point is a point set before the start point of the heavy braking section on the travel route of the vehicle 10, the battery control unit 710 reduces the SOC value of the battery 30 in the section from the SOC adjustment start point to the start point of the heavy braking section. This configuration makes it possible to more accurately reduce the SOC value of the battery 30.

[0044] (5) The battery control unit 710 drives the auxiliary machinery 31 in the section from the SOC adjustment start point to the start point of the heavy braking section, thereby reducing the SOC value of the battery 30. This configuration makes it possible to easily reduce the SOC value of the battery 30. (6) The battery control unit 710 sets the SOC adjustment start point based on the current SOC value of the battery 30 and the target SOC value of the battery 30 at the start point of the heavy braking section. This configuration makes it possible to easily set the SOC adjustment start point.

[0045] (First Modification) Next, a first modification of the vehicle 10 of the first embodiment will be described. The section prediction unit 730 is not limited to using map information as a means for predicting a section where braking is frequently used, and can use any means.

[0046] For example, the section prediction unit 730 may predict a section requiring heavy braking using image data captured by the imaging device 52. Specifically, the section prediction unit 730 acquires information about road signs provided on the road on which the vehicle 10 is traveling by performing appropriate image analysis processing on the image data. Road signs include signs indicating the gradient of a downhill slope and signs indicating the legal speed limit for the road. The section prediction unit 730 may predict the presence of a section requiring heavy braking if the acquired image data includes a sign indicating the gradient of a downhill slope and the gradient of the downhill slope is equal to or greater than a predetermined value. In this case, the section prediction unit 730 constantly monitors whether a section requiring heavy braking exists on the future traveling route of the vehicle 10 while the vehicle 10 is traveling.

[0047] Furthermore, the section prediction unit 730 may predict a heavy braking section based on learning information about the driving state of the vehicle 10. Specifically, the vehicle 10 is further equipped with a learning device 53, as indicated by the dashed line in FIG. 2. The learning device 53 correlates and learns information such as the current position of the vehicle 10, the amount of accelerator pedal operation, the amount of brake pedal operation, and the driving speed of the vehicle 10. The section prediction unit 730 acquires learning information about the driving state of the vehicle 10 from the learning device 53 and predicts a heavy braking section based on the acquired learning information. For example, when there are multiple consecutive points where the frequency of brake pedal operation per unit time is equal to or greater than a predetermined frequency, the section prediction unit 730 predicts that the section between those multiple points is a heavy braking section. In this modification, the learning device 53 corresponds to the learning unit.

[0048] When predicting a section where braking is intensive in this manner, the section prediction unit 730 may predict, based on learning information, whether or not there is a section where braking is intensive on the driving route of the vehicle 10 at the time the driving route of the vehicle 10 is set in the navigation device 51. Furthermore, the section prediction unit 730 may predict a section where braking is required frequently while the vehicle 10 is traveling. Specifically, the section prediction unit 730 may predict, based on the learning information, whether or not a section where braking is required frequently exists in a section from the current position of the vehicle 10 to a point a predetermined distance ahead on the travel route on which the vehicle 10 is currently traveling.

[0049] (Second Modification) Next, a second modified example of the vehicle 10 of the first embodiment will be described. The battery control unit 710 is not limited to driving the auxiliary machinery 31 as a means for lowering the SOC value of the battery 30, and can use any means.

[0050] For example, when the driver brakes in a section from the SOC adjustment start point to the start point of the heavy braking section, the battery control unit 710 may increase the proportion of braking force applied to the vehicle 10 by the friction brake device 40, while decreasing the proportion of braking force applied to the vehicle 10 by the regenerative operation of the motor generator 21, thereby decreasing the SOC value of the battery 30. Specifically, the battery control unit 710 may decrease the braking force applied to the vehicle 10 by the regenerative operation of the motor generator 21 in the section from the SOC adjustment start point to the start point of the heavy braking section, compared to braking force generated in a section other than the section from the SOC adjustment start point to the start point of the heavy braking section, thereby decreasing the SOC value of the battery 30. For example, if the normal setting value of the upper limit value TBR1max* of the first braking torque command value is "Ta," the battery control unit 710 sets the upper limit value TBR1max* of the first braking torque command value to "Ta-c" in the section from the SOC adjustment start point to the start point of the heavy braking section. The predetermined value c is set to "c>0".

[0051] Furthermore, battery control unit 710 may reduce the regenerative efficiency of motor generator 21 by, for example, switching control of motor generator 21 in the section from the SOC adjustment start point to the start point of the heavy braking section. This reduces the amount of power charged to battery 30, even if motor generator 21 performs a regenerative operation when the driver applies the brakes, and therefore the SOC value of battery 30 can be reduced.

[0052] Furthermore, the battery control unit 710 may lower the SOC value of the battery 30 by operating the motor generator 21, which corresponds to the main machinery, in a state where the driving efficiency is reduced in the section from the start point of the SOC adjustment to the start point of the heavy braking section. The battery control unit 710 may use a combination of the above-described means capable of reducing the SOC value of the battery 30. For example, if the current SOC value of the battery 30 when the vehicle 10 reaches the SOC adjustment start point is equal to or greater than a predetermined value, the battery control unit 710 may execute a process to forcibly drive the accessories 31, and if the current SOC value of the battery 30 is less than the predetermined value, the battery control unit 710 may execute a process to reduce the braking force applied to the vehicle 10 by the regenerative operation of the motor generator 21.

[0053] Second Embodiment Next, a vehicle 10 according to a second embodiment will be described. The following description will focus on the differences from the vehicle 10 according to the first embodiment. The ECUs 71 to 73 of this embodiment execute the process shown in Fig. 5. In the process shown in Fig. 5, the same processes as those shown in Fig. 3 are denoted by the same reference numerals, and redundant explanations will be omitted.

[0054] As shown in FIG. 5, if the section prediction unit 730 makes a positive determination in the process of step S11, the temperature prediction unit 731 calculates the maximum temperature TBR of the friction brake device 40 in the heavy braking section as the process of step S20. max Specifically, the following is predicted:

[0055] First, the potential energy U of the vehicle 10 lost when the vehicle 10 travels from the highest altitude point to the lowest altitude point in the braking-intensive section can be expressed by the following equation f1.

[0056]

number

[0057] On the other hand, the situation in which the brakes are used most frequently in a braking-heavy section is considered to be a situation in which the vehicle 10 is stopped at the lowest altitude in the braking-heavy section. In this case, the kinetic energy K lost by the vehicle 10 can be expressed by the following equation f2.

[0058]

number

[0059] When the potential energy U and kinetic energy K of the vehicle 10 are used, the maximum temperature TBR of the friction brake device 40 in the braking heavy section is max can be estimated using the following formula f3.

[0060]

number

[0061] The braking energy C due to regenerative torque is, in other words, the kinetic energy of the vehicle 10 lost due to the regenerative operation of the motor generator 21 in the heavy braking section, or, in further words, the kinetic energy of the vehicle 10 converted into thermal energy of the motor generator 21 and electrical energy of the battery 30 due to the regenerative operation of the motor generator 21. The braking energy C due to regenerative torque is calculated by the temperature prediction unit 731 using an arithmetic expression or the like. For example, when the vehicle 10 reaches a point a predetermined distance before the start point of the heavy braking section, the temperature prediction unit 731 predicts the temperature and SOC value of the battery 30 at each point in the heavy braking section based on the changes in the temperature and SOC value of the battery 30 up to that point. The temperature prediction unit 731 then calculates the braking energy ΔC due to regenerative torque at each point based on the predicted values ​​of the temperature and SOC value of the battery 30 at each point in the heavy braking section, using an arithmetic expression or the like. Then, the temperature prediction unit 731 calculates the braking energy C due to the regenerative torque in the heavy braking section by integrating the calculated braking energy ΔC due to the regenerative torque at each point.

[0062] The weight m and specific heat C of the friction brake device 40 are stored in advance in the ROM of the prediction ECU 73 . Estimated temperature TBR of the friction brake device 40 at the beginning of the heavy braking section S is calculated by the temperature prediction unit 731. For example, when the vehicle 10 reaches a point a predetermined distance before the start point of the heavy braking section, the temperature prediction unit 731 calculates an estimated value TBR of the temperature of the friction brake device 40 at the start point of the heavy braking section based on the change in the temperature of the battery 30 up to that point. S Calculate the following.

[0063] The adjustment term α is a term that takes into account temperature changes in the friction brake device 40 due to the outside air temperature, wind while driving, etc. The adjustment term α is calculated by the temperature prediction unit 731. For example, the temperature prediction unit 731 calculates the adjustment term α based on a map, an arithmetic expression, etc., from the outside air temperature detected by the outside air temperature sensor 62, the legal speed limit in the braking heavy use section, etc.

[0064] As shown in FIG. 5, in step S20, the temperature prediction unit 731 calculates the maximum temperature TBR of the friction brake device 40 in the heavy braking section based on the above formula f3. max After calculating the maximum temperature TBR of the friction brake device 40 calculated in step S20, the temperature prediction unit 731 determines in step S21 whether there is a possibility that the friction brake device 40 will be in a high temperature state in the heavy braking section. max The temperature rise rate AB of the friction brake device 40 is calculated based on the following equation f4.

[0065]

number

[0066] If the temperature rise rate AB is equal to or greater than a predetermined value, the temperature prediction unit 731 determines that there is a possibility that the friction brake device 40 will be in a high temperature state in the heavy braking section, i.e., makes a positive determination in the processing of step S21. On the other hand, if the temperature rise rate AB is less than the predetermined value, the temperature prediction unit 731 makes a negative determination in the processing of step S21.

[0067] According to the vehicle 10 of the present embodiment described above, the following action and effect described in (7) can be further obtained. (7) The temperature prediction unit 731 calculates the maximum temperature TBR of the friction brake device 40 based on road information such as the maximum altitude Hmax and minimum altitude Hmin in the braking heavy section, and information such as the traveling speed v of the vehicle 10. max According to this configuration, it is possible to more accurately predict the temperature of the friction brake device 40.

[0068] Third Embodiment Next, a vehicle 10 according to a third embodiment will be described, focusing on differences from the vehicle 10 according to the second embodiment. 2, the vehicle 10 of this embodiment further includes an alarm device 54. The alarm device 54 is a device that issues various types of alarms to the driver by sound emitted from a speaker, lighting up an indicator, etc.

[0069] 2, the cruise control ECU 72 further includes an abnormality detection unit 724. The abnormality detection unit 724 detects abnormalities in the navigation device 51, the image capture device 52, the on-board sensor 60, etc. When an abnormality occurs in at least one of the navigation device 51, the image capture device 52, and the on-board sensor 60, the abnormality detection unit 724 predicts a braking heavy section and the maximum temperature TBR of the friction brake device 40. max In this case, it may be difficult to perform the process shown in FIG. max Therefore, when an abnormality occurs in the on-board sensor 60 or the like, the abnormality detection unit 724 of this embodiment notifies the driver of the abnormality via the notification device 54, and also executes a process to prevent the temperature of the friction brake device 40 from rising.

[0070] Next, the procedure of the processing executed by the ECUs 71 to 73 of this embodiment will be specifically described with reference to Fig. 6. Note that in the processing shown in Fig. 6, the same processing as that shown in Fig. 5 is denoted by the same reference numerals, and redundant description will be omitted. 6, in step S30, the abnormality detection unit 724 of the cruise control ECU 72 determines whether the on-board sensors 60, etc. are normal. If the abnormality detection unit 724 determines that the on-board sensors 60, etc. are normal, it makes a positive determination in step S30 and executes the processes from step S10 onwards.

[0071] On the other hand, if the abnormality detection unit 724 determines that an abnormality has occurred in the on-board sensor 60 or the like, it makes a negative determination in the process of step S30. In this case, the abnormality detection unit 724 notifies the driver of the abnormality via the alarm device 54 in the process of step S31. Subsequently, the abnormality detection unit 724 executes a proportion adjustment process in step S32. Specifically, when the driver brakes, the abnormality detection unit 724 reduces the proportion of braking force applied to the vehicle 10 by the friction brake device 40, while increasing the proportion of braking force applied to the vehicle 10 by the regenerative operation of the motor generator 21. For example, if the normal setting value of the upper limit value TBR1max* of the first braking torque command value is "Ta," the abnormality detection unit 724 sets the upper limit value TBR1max* of the first braking torque command value to "Ta+d" in the section from the SOC adjustment start point to the start point of the heavy braking section. Note that the predetermined value d is set to "d>0."

[0072] Next, the abnormality detection unit 724 executes an energy consumption increase process as the process of step S33. Specifically, the abnormality detection unit 724 executes a process of driving the auxiliary machinery 31 that is the target of the forced driving, thereby consuming as much electric energy as possible that is generated by the regenerative operation of the motor generator 21.

[0073] According to the vehicle 10 of the present embodiment described above, the following action and effect described in (8) can be further obtained. (8) If an abnormality occurs in the on-board sensor 60, etc., the proportion of braking force applied to the vehicle 10 by the friction brake device 40 decreases, thereby reducing the burden on the friction brake device 40. This makes it possible to suppress temperature increases in the friction brake device 40. Furthermore, because as much electrical energy as possible generated by the regenerative operation of the motor generator 21 is consumed, the SOC value of the battery 30 is less likely to reach the upper limit value SOCmax. This makes it possible to continue the regenerative operation of the motor generator 21.

[0074] <Fourth embodiment> Next, a vehicle 10 according to a fourth embodiment will be described, focusing on the differences from the vehicle 10 according to the second embodiment. As shown by the dashed line in Figure 2, the vehicle 10 of this embodiment further includes a lift axle device 55. The lift axle device 55 is a device that can lift or ground any of the multiple wheels of the vehicle 10, and is sometimes mounted on large trailers and the like. The vehicle 10 normally travels with any of the multiple wheels lifted by the lift axle device 55.

[0075] The ECUs 71 to 73 of this embodiment execute the process shown in Fig. 7. In the process shown in Fig. 7, the same processes as those shown in Fig. 5 are denoted by the same reference numerals, and redundant explanations will be omitted. 7, after the battery control unit 710 executes the process of step S13, the battery control unit 710 determines, in the process of step S40, whether or not the friction brake device 40 can be prevented from reaching a high temperature state by the SOC adjustment process alone. For example, if any of the following conditions (d1) to (d6) is satisfied, the battery control unit 710 determines that the friction brake device 40 cannot be prevented from reaching a high temperature state by the SOC adjustment process alone.

[0076] (d1) Maximum temperature TBR of the friction brake device 40 in the heavy braking section max exceeds a predetermined value. (d2) When the SOC value of the battery 30 is predicted to reach the upper limit value SOCmax in a braking-intensive section, and furthermore, the predicted value of the cumulative value of the braking force required by the vehicle 10 after the SOC value of the battery 30 reaches the upper limit value SOCmax by the time the vehicle 10 reaches the end point of the braking-intensive section exceeds a predetermined value.

[0077] (d3) When the SOC value of the battery 30 is predicted to reach the upper limit value SOCmax in a braking-heavy section, and the time required for the vehicle 10 to reach the end point of the braking-heavy section after the SOC value of the battery 30 reaches the upper limit value SOCmax is longer than a predetermined time.

[0078] (d4) The current SOC value of the battery 30 is higher than the upper limit value SOCmax, and the length of the heavy braking section exceeds a predetermined length. (d5) The current SOC value of the battery 30 is higher than the upper limit value SOCmax, and the average gradient of the heavy braking section exceeds a predetermined value.

[0079] (d6) The current SOC value of the battery 30 is higher than the upper limit value SOCmax, and the time required to pass through the heavy braking section exceeds a predetermined time. If any of the above conditions (d1) to (d6) is satisfied, for example, the battery control unit 710 makes a negative determination in the process of step S40. In this case, the battery control unit 710 drives the lift axle device 55 to bring all of the wheels into contact with the ground as the process of step S41.

[0080] According to the vehicle 10 of the present embodiment described above, the following action and effect described in (9) can be further obtained. (9) If the SOC adjustment process alone cannot prevent the friction brake device 40 from reaching a high temperature, all of the wheels are grounded by the lift axle device 55. As a result, compared to when the friction brake device 40 applies braking torque to only some of the wheels, when the friction brake device 40 applies braking torque to all of the wheels, the burden on the friction brake device 40 corresponding to each wheel can be reduced. Therefore, even if the SOC adjustment process alone cannot prevent the friction brake device 40 from reaching a high temperature, the temperature rise of the friction brake device 40 can be suppressed as much as possible.

[0081] Fifth Embodiment Next, a vehicle 10 according to a fifth embodiment will be described, focusing on differences from the vehicle 10 according to the second embodiment. If the regenerative operation of the motor generator 21 is continuously performed in a section where braking is frequently performed, the power train equipment 20, such as the motor generator 21 and the inverter device 23, may become hot. This is undesirable because it may cause an abnormality in the power train equipment 20.

[0082] Therefore, in the vehicle 10 of this embodiment, when it is predicted that there is a low possibility that the friction brake device 40 will reach a high temperature in a section where braking is frequently performed, and when it is predicted that there is a high possibility that the powertrain equipment 20 will reach a high temperature, the proportion of braking force applied to the vehicle 10 by the friction brake device 40 is increased, while the proportion of braking force applied to the vehicle 10 by the regenerative operation of the motor generator 21 is reduced, thereby suppressing the temperature rise of the powertrain equipment 20.

[0083] Specifically, the ECUs 71 to 73 of this embodiment execute the process shown in Fig. 8. In the process shown in Fig. 8, the same processes as those shown in Fig. 5 are denoted by the same reference numerals, and redundant explanations will be omitted. In the following, the process of step S13 will be referred to as a first SOC adjustment process, and the target SOC value used in the process of step S13 will be referred to as a first target SOC value.

[0084] As shown in FIG. 8, in the process of step S50 following step S20, the temperature prediction unit 731 calculates the maximum temperature TP of the powertrain device 20 in the heavy braking section. max Specifically, when the potential energy U of the vehicle 10 calculated by the above formula f1 and the kinetic energy K calculated by the above formula f2 are used, the maximum temperature TP of the powertrain device 20 is predicted as follows: max can be calculated using the following formula f5.

[0085]

number

[0086] Regeneration efficiency E M , weight of powertrain equipment 20 m P , and the specific heat c of the powertrain equipment 20 P is stored in the ROM of the prediction ECU 73. Estimated temperature TP of the powertrain component 20 at the start of the braking-intensive section S is calculated by the temperature prediction unit 731. For example, when the vehicle 10 reaches a point a predetermined distance before the start point of the heavy braking section, the temperature prediction unit 731 calculates an estimated value TP of the temperature of the powertrain device 20 at the start point of the heavy braking section based on the transition of the temperature of the powertrain device 20 up to that point. S Calculate the following.

[0087] The adjustment term β is set by the same or similar method as the adjustment term α described in the second embodiment. In step S21 following step S50, the temperature prediction unit 731 determines whether or not there is a possibility that the friction brake device 40 will reach a high temperature in the heavy braking section. If the temperature prediction unit 731 determines that there is a possibility that the friction brake device 40 will reach a high temperature, the temperature prediction unit 731 makes a positive determination in the process of step S21. In this case, the battery control unit 710 executes a first SOC adjustment process in the process of step S13.

[0088] If the temperature prediction unit 731 determines that there is no possibility that the friction brake device 40 will reach a high temperature in the heavy braking section, it makes a negative determination in the process of step S21. In this case, the temperature prediction unit 731 determines whether or not there is a possibility that the powertrain device 20 will reach a high temperature in the process of step S51. Specifically, the temperature prediction unit 731 calculates the maximum temperature TP of the powertrain device 20 calculated in step S50. maxThe temperature rise rate AP of the powertrain device 20 is calculated based on the following equation f6.

[0089]

number

[0090] On the other hand, if the temperature rise rate AP is equal to or greater than a predetermined value, the temperature prediction unit 731 determines that there is a possibility that the powertrain device 20 will be in a high temperature state in the heavy braking section, i.e., makes a positive determination in the processing of step S51. In this case, the temperature prediction unit 731 sets a second target SOC value for the battery 30 at the start point of the heavy braking section and transmits information about the start point of the heavy braking section and the second target SOC value to the battery control unit 710. The second target SOC value is a target value for the SOC value that the battery 30 needs to have at the start point of the heavy braking section so that the SOC value of the battery 30 will not reach the upper limit value SOCmax even if the motor generator 21 performs regenerative operation in the section from the start point to the end point of the heavy braking section while reducing the proportion of braking force applied to the vehicle 10 by the regenerative operation of the motor generator 21. In other words, if the SOC value of the battery 30 reaches the second target SOC value at the start point of the heavy braking section, it can be estimated that the SOC value of the battery 30 will not reach the upper limit value SOCmax at the end point of the heavy braking section. The second target SOC value may be a fixed value or a variable value. When the second target SOC value is a variable value, the temperature prediction unit 731 sets the second target SOC value using an arithmetic expression, a map, or the like based on, for example, the length of the braking heavy section or the average gradient.

[0091] The battery control unit 710 performs a second SOC adjustment process as the process of step S52 following step S51. In this embodiment, the amount of power increase per unit time when one or more auxiliary machines 31 that are subject to a forced stop are stopped is determined in advance through experiments or the like, and information on the amount of power increase per unit time is stored in advance in the ROM of the battery ECU 71. While the vehicle 10 is traveling toward the destination, the battery control unit 710 monitors the transition of the current SOC value of the battery 30 and calculates the time required to increase the SOC value of the battery 30 to the second target SOC value from the start of the forced stop of the auxiliary machines 31 by subtracting the current SOC value from the second target SOC value and dividing the result by the amount of power increase per unit time. Based on the calculated time and information such as the legal speed limit of the road, the battery control unit 710 calculates a required mileage, which is the mileage required to increase the SOC value of the battery 30 to the second target SOC value, and sets a point that is the required mileage before the start of the heavy braking section as the SOC adjustment start point. Then, when the battery control unit 710 determines that the vehicle 10 has reached the SOC adjustment start point, it forcibly stops the auxiliary machines 31 that are the target of the forcible stop. The battery control unit 710 continues to forcibly stop the auxiliary machines 31 until the vehicle 10 reaches the start point of the heavy braking section. After the battery control unit 710 executes the process of step S52, the process shown in FIG. 8 ends.

[0092] Next, an example of the operation of the vehicle 10 of this embodiment will be described. As shown in Fig. 9, when the vehicle 10 reaches the SOC adjustment start point at time t20, a forced stop of the accessories 31 is initiated. The forced stop of the accessories 31 reduces the power consumption of the battery 30, and the SOC value of the battery 30 increases due to the power generated by the regenerative operation of the motor generator 21. Therefore, as shown in Fig. 9(A), the SOC value of the battery 30 increases during the period from time t20 to time t21. Time t21 is the time when the vehicle 10 reaches the start point of the heavy braking section.

[0093] When the vehicle 10 reaches the start point of the heavy braking section at time t21, as shown in Figure 9(B), the proportion of braking force applied to the vehicle 10 by the friction brake device 40 is increased, while the proportion of braking force applied to the vehicle 10 by the regenerative operation of the motor generator 21 is reduced. As a result, the power generated by the regenerative operation of the motor generator 21 decreases, so that the SOC value of the battery 30 does not reach the upper limit value SOCmax at time t22, as shown in Figure 9(A). Time t22 is the time when the vehicle 10 reaches the end point of the heavy braking section.

[0094] 9(C), it is also possible to prevent the temperature TP of the powertrain device 20 from reaching the upper limit temperature TPth at time t22, at which an abnormality may occur. Furthermore, as shown by the dashed-dotted line in FIG. 9(C), it is possible to prevent the temperature TBR of the friction brake device 40 from rising sharply, so it is also possible to prevent the temperature TBR of the friction brake device 40 from reaching the upper limit temperature at which an abnormality may occur.

[0095] According to the vehicle 10 of the present embodiment described above, the following action and effect described in (10) can be further obtained. (10) The temperature prediction unit 731 predicts the maximum temperature TP of the powertrain device 20. max The battery control unit 710 predicts the maximum temperature TP of the powertrain device 20. max The state of charge of the battery 30 is adjusted based on the above. This configuration makes it possible to prevent the temperature of the powertrain device 20 from rising too high in a section where braking is frequently used.

[0096] (First Modification) Next, a first modified example of the vehicle 10 of the fifth embodiment will be described. In the process of step S51 shown in FIG. 8, the temperature prediction unit 731 may determine that the powertrain device 20 is likely to be in a high temperature state when, for example, any of the following conditions (e1) to (e4) is satisfied.

[0097] (e1) Maximum temperature TP of powertrain equipment 20 in a section where braking is frequently used max exceeds a predetermined value. (e2) The current temperature of the powertrain device 20 is higher than the upper limit temperature TPth, and the length of the heavy braking section exceeds a predetermined length.

[0098] (e3) The current temperature of the powertrain device 20 is higher than the upper limit temperature TPth and the average gradient of the heavy braking section exceeds a predetermined value. (e4) The current temperature of the powertrain device 20 is higher than the upper limit temperature TPth, and the time required to pass through the heavy braking section exceeds a predetermined time.

[0099] (Second Modification) Next, a second modification of the vehicle 10 of the fifth embodiment will be described. The battery control unit 710 is not limited to stopping the auxiliary machinery 31 as a means for increasing the SOC of the battery 30, and can employ any means.

[0100] For example, when the driver brakes in the section from the SOC adjustment start point to the start point of the heavy braking section, the battery control unit 710 may increase the SOC value of the battery 30 by reducing the proportion of braking force applied to the vehicle 10 by the friction brake device 40, while increasing the proportion of braking force applied to the vehicle 10 by the regenerative operation of the motor generator 21.

[0101] Sixth Embodiment Next, a vehicle 10 according to a sixth embodiment will be described. The following description will focus on the differences from the vehicle 10 according to the fifth embodiment. If the regenerative operation of the motor generator 21 continues in a section where braking is heavy, not only the powertrain equipment 20 but also the battery 30 may reach a high temperature. If the battery 30 reaches a high temperature, this is undesirable as it may cause an abnormality in the battery 30. Therefore, in the vehicle 10 of this embodiment, when it is predicted that the friction brake device 40 is unlikely to reach a high temperature in a section where braking is heavy, but it is predicted that the battery 30 is likely to reach a high temperature, the proportion of braking force applied to the vehicle 10 by the friction brake device 40 is increased, while the proportion of braking force applied to the vehicle 10 by the regenerative operation of the motor generator 21 is reduced, thereby suppressing a temperature rise in the battery 30.

[0102] Specifically, the ECUs 71 to 73 of this embodiment execute the process shown in Fig. 10. In the process shown in Fig. 10, the same processes as those shown in Fig. 8 are denoted by the same reference numerals, and redundant explanations will be omitted. As shown in FIG. 10, in the process of step S60 following step S20, the temperature prediction unit 731 calculates the maximum temperature TBT max Specifically, when the potential energy U of the vehicle 10 calculated by the above formula f1 and the kinetic energy K calculated by the above formula f2 are used, the maximum temperature TBT of the battery 30 is predicted. max can be calculated using the following formula f7.

[0103]

number

[0104] Estimated temperature TBT of battery 30 at the start of the heavy braking section S is calculated by the temperature prediction unit 731. The estimated value TBT of the temperature of the battery 30 S is the estimated temperature of the powertrain component 20, TP S can be calculated in the same or similar manner as The adjustment term γ is set by the same or similar method as the adjustment term α used in the second embodiment and the adjustment term β used in the fifth embodiment.

[0105] If the determination in step S21 is negative, the temperature prediction unit 731 determines in step S61 whether the battery 30 will be in a high temperature state in the braking heavy section. Specifically, the temperature prediction unit 731 determines whether the battery 30 will be in a high temperature state in the braking heavy section. max is equal to or lower than the predetermined temperature, it is determined that there is no possibility that the battery 30 will become hot in the heavy braking section. In this case, after the temperature prediction unit 731 makes a negative determination in the processing of step S61, the processing shown in FIG. 10 is terminated.

[0106] On the other hand, the temperature prediction unit 731 calculates the maximum temperature TBT of the battery 30 calculated in the process of step S60. max exceeds the predetermined temperature, it is determined that there is a possibility that the battery 30 will be in a high temperature state in the section where braking is frequently used. In this case, after the temperature prediction unit 731 makes a positive determination in the process of step S61, the battery control unit 710 executes the process of step S52.

[0107] According to the vehicle 10 of the present embodiment described above, the following action and effect described in (11) can be further obtained. (11) The temperature prediction unit 731 calculates the maximum temperature TBT of the battery 30. maxThe battery control unit 710 predicts the maximum temperature TBT of the battery 30. max The state of charge of the battery 30 is adjusted based on the above. This configuration makes it possible to prevent the temperature of the battery 30 from rising too high in sections where braking is frequently used.

[0108] (Variation) Next, a modified example of the vehicle 10 of the sixth embodiment will be described. The order of the processes shown in Fig. 10 can also be changed to the order shown in Fig. 11. As shown in Fig. 11, the temperature prediction unit 731 of this modified example executes the determination process of step S61 with priority over the determination process of step S21. That is, prior to the determination process of step S21, the temperature prediction unit 731 determines, in the process of step S61, whether or not there is a possibility that the battery 30 will reach a high temperature in the heavy braking section. If the temperature prediction unit 731 determines that there is no possibility that the battery 30 will reach a high temperature, it makes a negative determination in the process of step S61. In this case, in the process of step S21, the temperature prediction unit 731 determines whether or not there is a high possibility that the friction brake device 40 will reach a high temperature.

[0109] This configuration can more reliably prevent the battery 30 from reaching a high temperature state. <Other embodiments> The above embodiment can also be implemented in the following manner.

[0110] The vehicle 10 is not limited to an electric vehicle, but may be, for example, a so-called hybrid vehicle that runs using a motor generator and an engine as power sources. The ECUs 71-73 and the control method thereof described in the present disclosure may be implemented by one or more special-purpose computers configured by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. The ECUs 71-73 and the control method thereof described in the present disclosure may be implemented by a special-purpose computer configured by configuring a processor including one or more dedicated hardware logic circuits. The ECUs 71-73 and the control method thereof described in the present disclosure may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to execute one or more functions with a processor including one or more hardware logic circuits. The computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible recording medium. The dedicated hardware logic circuit and the hardware logic circuit may be implemented by a digital circuit including multiple logic circuits or an analog circuit.

[0111] The present disclosure is not limited to the specific examples described above. Design modifications made by a person skilled in the art to the specific examples described above are also included within the scope of the present disclosure as long as they incorporate the features of the present disclosure. The elements of the specific examples described above, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of the specific examples described above can be combined in various ways as long as no technical contradictions arise.

[0112] <Additional Notes> Other features of the present invention are as follows. 7. The vehicle according to claim 1, wherein the temperature prediction unit predicts the temperature of the friction brake device based on road information for the predetermined section and information about the vehicle.

[0113] The vehicle according to any one of claims 1 to 9, wherein the battery control unit reduces the state of charge of the battery in a section from a point set before the start point of the predetermined section on the vehicle's travel route to the start point of the predetermined section, when the predetermined point is the point set before the start point of the predetermined section.

[0114] 15. The vehicle according to claim 1, wherein the temperature prediction unit further predicts at least one of a temperature of a powertrain device (20) including the rotating electric machine and a temperature of the battery, and the battery control unit further adjusts a state of charge of the battery based on at least one of the predicted temperature of the powertrain device and the predicted temperature of the battery.

[0115] 13. The vehicle control device according to claim 12, wherein the electrical load is a main engine. [Explanation of symbols]

[0116] 10: Vehicle 20: Powertrain equipment 30: Battery 31: Auxiliary equipment 40: Friction brake device 53: Learning device (learning section) 710: Battery control unit 722: Motor control unit (rotating electric machine control unit) 730: Interval prediction unit 731: Temperature prediction section

Claims

1. A vehicle (10) having a friction brake device (40) that applies a braking force based on friction force to a vehicle, a rotating electric machine (21) that applies a braking force based on regenerative torque to the vehicle, and a battery (30) that stores electric power generated by a regenerative operation of the rotating electric machine, a temperature prediction unit (731) for predicting a temperature of the friction brake device when the vehicle travels a predetermined section; a rotating electric machine control unit (722) that controls the rotating electric machine so as to limit a regenerative operation of the rotating electric machine based on the state of charge of the battery reaching a predetermined upper limit state; a battery control unit (710) that controls the battery so as to reduce the state of charge of the battery before the vehicle reaches the predetermined section when it is predicted that the temperature of the friction brake device will reach or exceed a predetermined temperature; The battery control unit When a point set before a start point of the predetermined section on a travel route of the vehicle is set as the predetermined point, the state of charge of the battery is reduced in a section from the predetermined point to the start point of the predetermined section, Driving an electrical load of the vehicle in a section from the predetermined point to a start point of the predetermined section reduces the state of charge of the battery. vehicle.

2. The electrical load is an auxiliary device (31) mounted on the vehicle. The vehicle of claim 1 .

3. The battery control unit sets the predetermined point based on a current state of charge of the battery and a target state of charge of the battery at a start point of the predetermined section.

3. A vehicle according to claim 1 or 2.

4. A vehicle (10) having a friction brake device (40) that applies a braking force based on friction force to a vehicle, a rotating electric machine (21) that applies a braking force based on regenerative torque to the vehicle, and a battery (30) that stores electric power generated by a regenerative operation of the rotating electric machine, a temperature prediction unit (731) for predicting a temperature of the friction brake device when the vehicle travels a predetermined section; a rotating electric machine control unit (722) that controls the rotating electric machine so as to limit a regenerative operation of the rotating electric machine based on the state of charge of the battery reaching a predetermined upper limit state; a battery control unit (710) that controls the battery so as to reduce the state of charge of the battery before the vehicle reaches the predetermined section when it is predicted that the temperature of the friction brake device will reach or exceed a predetermined temperature; the temperature prediction unit further predicts the temperature of a powertrain device (20) including the rotating electric machine and the temperature of the battery; the battery control unit controls the battery to lower the state of charge of the battery when the predicted temperature of the powertrain device is predicted to be in a high temperature state even when the temperature of the friction brake device is not predicted to be equal to or higher than a predetermined temperature. vehicle.

5. A vehicle (10) having a friction brake device (40) that applies a braking force based on friction force to a vehicle, a rotating electric machine (21) that applies a braking force based on regenerative torque to the vehicle, and a battery (30) that stores electric power generated by a regenerative operation of the rotating electric machine, a temperature prediction unit (731) for predicting a temperature of the friction brake device when the vehicle travels a predetermined section; a rotating electric machine control unit (722) that controls the rotating electric machine so as to limit a regenerative operation of the rotating electric machine based on the state of charge of the battery reaching a predetermined upper limit state; a battery control unit (710) that controls the battery so as to reduce the state of charge of the battery before the vehicle reaches the predetermined section when it is predicted that the temperature of the friction brake device will reach or exceed a predetermined temperature; the temperature prediction unit further predicts the temperature of a powertrain device (20) including the rotating electric machine and the temperature of the battery; the battery control unit controls the battery to lower the state of charge of the battery when the predicted temperature of the battery is predicted to be in a high temperature state even when it is not predicted that the temperature of the friction brake device will be equal to or higher than a predetermined temperature. vehicle.

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