Vehicle control device

Abstract

To provide a control device of a vehicle that can suppress deterioration in power performance and comfort in a vehicle interior, under a highland environment.SOLUTION: An electronic control device 90, of a vehicle 10 that is equipped with an engine 12, a motor generator MG that is rotationally driven by the engine 12 to generate electric power, and an air conditioner 50, limits power consumption Pcmp by a power generator 60a for a compressor that drives the air conditioner 50 to less than a predetermined power consumption Pcmp_lmt when a charging status value SOC of a main battery 40 that is charged with electric power generated by the power generator MG is less than a determination value SOC_jdg1 (a) and stops operation of the air conditioner 50 when the charging status value SOC is less than a determination value SOC_jdg2 (<SOC_jdg1) lower than the determination value SOC_jdg1 (b), when the vehicle 10 is running using the engine 12 as a power source and when the vehicle is under a predetermined highland environment.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control device for a vehicle that includes an engine, a rotating electric machine that is driven by the engine to rotate and generate electricity, and an air conditioner. [Background technology]

[0002] In a vehicle equipped with a rotating electric machine that is driven by an engine to generate electricity, when the vehicle is in a high-altitude environment, the engine output decreases, and there is a risk that the battery may not be charged. In such a case, a vehicle control device that stops the operation of the air conditioner is known. For example, the device described in Patent Document 1 is one such device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-175429 Summary of the Invention [Problem to be solved by the invention]

[0004] The vehicle control device described in Patent Document 1 may stop the operation of the air conditioner even when the battery's state of charge value has some margin. In such cases, the air conditioner may be stopped unnecessarily, which may reduce the comfort inside the vehicle cabin.

[0005] The present invention has been made against the background of the above circumstances, and its purpose is to provide a vehicle control device that can suppress a decrease in power performance in high altitude environments and suppress a decrease in comfort inside the vehicle cabin. [Means for solving the problem]

[0006] The gist of the present invention is a control device for a vehicle including an engine, a rotating electric machine that is driven by the engine to generate electricity, and an air conditioner, wherein, while the vehicle is running using the engine as a power source, securing driving force for running takes priority over power generation by the rotating electric machine, and the vehicle In a certain high altitude environment where the output of the engine is reduced due to low air density in the surrounding atmosphere and the cooling capacity of the air conditioner is not limited, it is not possible to ensure both the driving force for traveling and the charging of the battery by the power generation by the rotating electric machine. In the case where (a) the rotating electric machine The battery is charged by the generated power. The charging state value of a predetermined first threshold value that limits the cooling capacity of the air conditioner in order to ensure the driving force for traveling; (b) limiting the air conditioning capacity of the air conditioner to less than a predetermined amount if the state of charge value is less than a predetermined second threshold value that is lower than the first threshold value and stops the operation of the air conditioner to ensure the driving force for traveling; (c) stopping the operation of the air conditioner when the state of charge value is equal to or greater than the first threshold value; and (d) not limiting the air conditioning capacity of the air conditioner when the state of charge value is equal to or greater than the first threshold value. [Effects of the Invention]

[0007] According to the vehicle control device of the present invention, while the vehicle is running using the engine as a power source, securing a driving force for running is given priority over power generation by the rotating electric machine, and the vehicle In a certain high altitude environment where the output of the engine is reduced due to low air density in the surrounding atmosphere and the cooling capacity of the air conditioner is not limited, it is not possible to ensure both the driving force for traveling and the charging of the battery by the power generation by the rotating electric machine. In the case where (a) the rotating electric machine The battery is charged by the generated power. The charging state value of a predetermined first threshold value that limits the cooling capacity of the air conditioner in order to ensure the driving force for traveling; (b) if the state of charge value is less than 0.5 V, the air conditioning capacity of the air conditioner is limited to less than a predetermined amount; a predetermined second threshold value that is lower than the first threshold value and stops the operation of the air conditioner to ensure the driving force for traveling; (c) if the state of charge value is equal to or greater than the first threshold, the air conditioning capacity of the air conditioner is not limited. When the air density around the vehicle is low and the engine output is reduced, and the air conditioner's cooling capacity is not limited, it is not possible to ensure both the driving force for running and the battery charging by the rotating electric machine. In a high-altitude environment, if the battery's SOC has a margin of error, the air conditioning capacity of the air conditioner is not limited. On the other hand, if the battery's SOC is not sufficient, the air conditioning capacity of the air conditioner is limited or the air conditioner is turned off. In this way, the driving force for driving is ensured and the air conditioning capacity of the air conditioner is limited or turned off only when necessary, thereby preventing a decrease in power performance and a decrease in comfort inside the vehicle. [Brief explanation of the drawings]

[0008] [Figure 1]1 is a schematic configuration diagram of a vehicle equipped with an electronic control device according to a first embodiment. [Figure 2] 2 is an example of a flowchart illustrating the control operation of the electronic control device shown in FIG. 1. [Figure 3] FIG. 10 is a schematic configuration diagram of a vehicle equipped with an electronic control device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. Note that in each of the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of each part are not necessarily drawn accurately. [Example]

[0010] FIG. 1 is a schematic diagram of a vehicle 10 equipped with an electronic control device 90 according to the first embodiment.

[0011] The vehicle 10 is a hybrid vehicle equipped with an engine 12 and an electric motor MG as power sources. A clutch K0 connects and disconnects the engine 12 and the electric motor MG as power sources. In the vehicle 10, a power transmission path between the power source and drive wheels 14 is connected, in order from the power source side, to a transmission input shaft 24, an automatic transmission 16, a transmission output shaft 26, a differential 18, and an axle 28, all of which are well-known configurations. The vehicle 10 also includes a main battery 40, an auxiliary battery 42, an inverter 44, a converter 46, an air conditioner 50, auxiliary equipment 62, and an electronic control device 90.

[0012] The engine 12 is a well-known internal combustion engine. The electric motor MG is, for example, a rotating electric machine having a motor function and a generator function, and is a so-called motor generator. The electric motor MG corresponds to the "rotating electric machine" in the present invention.

[0013] The clutch K0 is a clutch that connects and disconnects power transmission between the engine 12 and the electric motor MG, and is, for example, a dry friction engagement device. One side of the clutch K0 is connected to the crankshaft 20 of the engine 12, and the other side of the clutch K0 is connected to the rotor shaft 22 of the electric motor MG. For example, the engine 12 is started by the electric motor MG outputting cranking torque for the engine 12 in conjunction with the clutch K0 switching from a released state to a fully engaged state via a partially engaged state.

[0014] The automatic transmission 16 is a well-known transmission that changes the rotation of a transmission input shaft 24 and outputs the rotation from a transmission output shaft 26. The transmission input shaft 24 is connected to the rotor shaft 22 so as not to rotate relative to the rotor shaft 22.

[0015] The main battery 40 is a chargeable and dischargeable secondary battery such as a lithium-ion battery pack or a nickel-metal hydride battery pack. The main battery 40 supplies, for example, power to drive the electric motor MG and power to charge the auxiliary battery 42. The main battery 40 is charged, for example, by power generated by the electric motor MG. The main battery 40 is a high-voltage battery with a higher charging voltage than the auxiliary battery 42. The main battery 40 corresponds to the "battery" in this invention.

[0016] The inverter 44 is a well-known power supply circuit that is provided between the electric motor MG and the main battery 40 and converts DC to AC and AC to DC under the control of the electronic control device 90. The MG torque Tmg [Nm], which is the output torque of the electric motor MG, is controlled by the inverter 44.

[0017] The auxiliary battery 42 is a chargeable and dischargeable secondary battery such as a lead-acid battery. The auxiliary battery 42 is a low-voltage battery with a lower charging voltage than the main battery 40. For example, the auxiliary battery 42 has a voltage of 12 V, whereas the main battery 40 has a higher voltage. The auxiliary battery 42 is charged by power supplied from the main battery 40 via a converter 46. The converter 46 is a well-known power supply circuit that is provided in the electrical path between the main battery 40 and the auxiliary battery 42 and that steps up and down the voltage of direct current.

[0018] The accessories 62 include an ignition device and a fuel injection device for the engine 12 for operating the engine 12, and in a broad sense also include an electronic control device 90 that controls the operation of the engine 12. The accessories 62 operate using power supplied from the auxiliary battery 42. In other words, the accessories 62 are an electrical load on the auxiliary battery 42.

[0019] The air conditioner 50 adjusts the temperature and humidity of the air inside the vehicle cabin. The air conditioner 50 is operated by an electric compressor 60. The electric compressor 60 is a well-known electric air compressor driven by a compressor motor 60a. The electronic control device 90 controls the rotation speed Nemt [rpm] and output torque Temt [Nm] of the compressor motor 60a, thereby controlling the cooling capacity of the air conditioner 50. The cooling capacity is expressed, for example, by the power consumption Pcmp [kWh] of the compressor motor 60a that drives the air conditioner 50. The amount of heat removed from the vehicle cabin per unit time by the air conditioner 50 is determined based on the power consumption Pcmp. The compressor motor 60a is operated by power supplied from the main battery 40. In other words, the compressor motor 60a is an electrical load on the main battery 40. The power consumption Pcmp is the same as the cooling capacity of the air conditioner 50, and corresponds to the "air conditioning capacity" in the present invention.

[0020] The vehicle 10 can select between two driving modes, for example, an electric motor driving mode in which the vehicle runs using the electric motor MG as the power source rather than the engine 12 as the power source, and an engine driving mode in which the vehicle runs using at least the engine 12 as the power source.

[0021] The electronic control device 90 is configured to include a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc., and the CPU executes various controls of the vehicle 10 by performing signal processing in accordance with programs previously stored in the ROM while utilizing the temporary storage function of the RAM. For example, the electronic control device 90 executes operation control of the engine 12, drive control of the electric motor MG including regenerative control of the electric motor MG, shift control of the automatic transmission 16, and engagement / disengagement control of the clutch K0, and controls the entire vehicle 10 as necessary. The electronic control device 90 corresponds to the "control device" in this invention.

[0022] The electronic control unit 90 receives various signals (e.g., accelerator opening θacc [%], which is the driver's accelerator operation amount indicating the magnitude of the driver's acceleration operation, vehicle speed V [km / h], battery temperature THbat [°C] of the main battery 40, battery charge / discharge current Ibat [A], battery voltage Vbat [V], atmospheric pressure APair [Pa] around the vehicle 10, etc.) based on detection values from various sensors (e.g., accelerator opening sensor 70, vehicle speed sensor 72, main battery sensor 74, atmospheric pressure sensor 76, etc.) provided on the vehicle 10.

[0023] The electronic control device 90 outputs various command signals (e.g., a control signal Scm for driving and controlling the compressor motor 60a) to each device (e.g., a compressor motor 60a that drives the electric compressor 60) provided in the vehicle 10.

[0024] Next, the control function of the electronic control device 90 when the vehicle 10 is running on the engine and the electric motor MG is driven to rotate by the engine 12 to generate electricity will be described.

[0025] The electronic control unit 90 calculates the drive amount (e.g., required drive torque Trdem [Nm]) required by the driver for the vehicle 10, for example, by applying the actual accelerator opening θacc and vehicle speed V to a required drive amount map. The required drive amount map is a map in which the relationship between the accelerator opening θacc, vehicle speed V, and the required drive amount is determined in advance experimentally or by design and stored. The required drive amount is the drive amount required for the vehicle 10, for example, the required drive torque Trdem. In other words, the required drive torque Trdem is the required drive power Prdem [W] at the vehicle speed V at that time. The required drive amount can also be the required drive force Frdem [N] at the drive wheels 14, or the like. In this way, the required drive torque Trdem, the required drive power Prdem, and the required drive force Frdem are all the same in that they are the required drive amounts of the vehicle 10.

[0026] During engine running, the electronic control device 90 controls the engine torque Te [Nm], which is the output torque of the engine 12, and the MG torque Tmg, which is the output torque of the electric motor MG, so as to realize the drive demand for the vehicle 10. When the electric motor MG is rotationally driven by the engine 12 to generate electricity, the MG torque Tmg is negative torque (= reaction torque), but the engine torque Te is sufficient to realize the drive demand and to drive the electric motor MG. Note that when the state-of-charge value SOC of the main battery 40 (the ratio of the amount of charge actually stored to a predetermined full charge capacity) is equal to or greater than a reference value SOC_jdg3 (described later), the electronic control device 90 controls the engine torque Te and the MG torque Tmg so as to prioritize realizing the drive demand, i.e., ensuring the driving force for traveling, over generating electricity by the electric motor MG. Furthermore, when the voltage of the auxiliary battery 42 drops below a predetermined voltage, the electronic control device 90 controls the auxiliary battery 42 to be charged from the main battery 40 via the converter 46, so that the engine 12 operates normally. The predetermined voltage is a voltage determined experimentally or by design at which the auxiliary battery 42 can supply power to the auxiliary device 62 so that the engine 12 operates normally.

[0027] The electronic control unit 90 determines whether the vehicle 10 is in a predetermined high-altitude environment. The predetermined high-altitude environment is an environment experimentally or design-predetermined in advance, in which the output of the engine 12 is reduced due to low air density around the vehicle 10, and thus it is not possible to ensure both sufficient driving force for traveling and sufficient charging of the main battery 40 through power generation by the electric motor MG if the cooling capacity of the air conditioner 50 is not limited. In other words, in a predetermined high-altitude environment, if the driving force for traveling is ensured without limiting the cooling capacity of the air conditioner 50, for example, charging of the main battery 40 through power generation by the electric motor MG may be insufficient, causing the rate of decrease Vdec [% / sec] of the state-of-charge (SOC) of the main battery 40 to fall outside the predetermined allowable range. Whether the vehicle is in a predetermined high-altitude environment is determined, for example, by determining whether the atmospheric pressure APair is less than a threshold pressure APair_jdg. The threshold pressure APair_jdg is a predetermined value experimentally or design-predetermined in advance to determine whether the vehicle is in a predetermined high-altitude environment.

[0028] The electronic control unit 90 calculates a state-of-charge value SOC [%] of the main battery 40 based on, for example, the battery charge / discharge current Ibat. The electronic control unit 90 determines whether the state-of-charge value SOC is less than a determination value SOC_jdg1 and whether the state-of-charge value SOC is less than a determination value SOC_jdg2. The determination value SOC_jdg2 is lower than the determination value SOC_jdg1. The determination value SOC_jdg1 is a determination value determined experimentally or by design for limiting the cooling capacity of the air conditioner 50 to ensure sufficient driving force. The determination value SOC_jdg2 is a determination value determined experimentally or by design for stopping operation of the air conditioner 50 to ensure sufficient driving force. The determination values SOC_jdg1 and SOC_jdg2 correspond to the "predetermined first threshold" and "predetermined second threshold," respectively, in the present invention. The state of charge of the main battery 40 is (a) most slack when the state of charge value SOC is equal to or greater than the judgment value SOC_jdg1, (b) least slack when the state of charge value SOC is less than the judgment value SOC_jdg2, and (c) somewhere between these when the state of charge value SOC is less than the judgment value SOC_jdg1 and equal to or greater than the judgment value SOC_jdg2.

[0029] When the vehicle 10 is in a predetermined high altitude environment while the engine is running (hereinafter referred to as "running in a high altitude environment") and the state of charge value SOC is equal to or greater than the determination value SOC_jdg1, the electronic control unit 90 does not limit the cooling capacity of the air conditioner 50. When the state of charge value SOC is less than the determination value SOC_jdg2 while running in a high altitude environment, the electronic control unit 90 stops the operation of the air conditioner 50. When the state of charge value SOC is less than the determination value SOC_jdg1 and equal to or greater than the determination value SOC_jdg2 while running in a high altitude environment, the electronic control unit 90 limits the power consumption Pcmp of the compressor motor 60a to less than a predetermined amount Pcmp_lmt. The predetermined amount Pcmp_lmt corresponds to the "predetermined amount" in the present invention and is a value determined experimentally or by design so as to suppress a decrease in comfort inside the vehicle cabin while ensuring driving force according to the state-of-charge value SOC of the main battery 40. Furthermore, by limiting the power consumption Pcmp of the compressor motor 60a to less than the predetermined amount Pcmp_lmt, driving force for driving is ensured in a predetermined high altitude environment, and the rate of decrease Vdec of the state-of-charge value SOC of the main battery 40 falls within a predetermined allowable range due to charging the main battery 40 using power generated by the electric motor MG.

[0030] If the cooling capacity of the air conditioner 50 is not limited when the vehicle is traveling in a high-altitude environment and the state-of-charge value SOC is less than the determination value SOC_jdg1 or even less than the determination value SOC_jdg2, the rate of decrease Vdec of the state-of-charge value SOC of the main battery 40 is not suppressed as much as when the cooling capacity of the air conditioner 50 is limited or the operation of the air conditioner 50 is stopped. This may result in a situation in which the power performance of the vehicle 10 is inevitably reduced. An example of a situation in which the power performance is inevitably reduced is a situation in which priority is given to ensuring power generation by the electric motor MG in order to operate the auxiliary equipment 62 normally, and the required drive amount cannot be achieved, i.e., the drive force for traveling cannot be secured.

[0031] For example, when the state of charge value SOC is less than the determination value SOC_jdg3 (≦SOC_jdg2) while traveling in a high-altitude environment, the electronic control device 90 stops operation of the air conditioner 50, but prioritizes power generation by the electric motor MG over ensuring driving force for traveling in order to ensure normal operation of the accessories 62. The determination value SOC_jdg3 is a determination value that is determined in advance through experimentation or design considerations in order to prioritize power generation by the electric motor MG over ensuring driving force for traveling when operation of the air conditioner 50 is stopped. As a result, although the requested driving amount cannot be achieved, a decrease in the state of charge value SOC of the main battery 40 is suppressed, and a state in which driving is possible is maintained, compared to when ensuring driving force for traveling is prioritized over power generation by the electric motor MG.

[0032] Preferably, when the state of charge value SOC is less than the determination value SOC_jdg1 and greater than or equal to the determination value SOC_jdg2, the predetermined amount Pcmp_lmt is set to a lower value as the state of charge value SOC decreases.

[0033] Fig. 2 is an example of a flowchart illustrating the control operation of the electronic control unit 90 shown in Fig. 1. The flowchart in Fig. 2 is repeatedly executed while the engine is running.

[0034] First, in step S10, it is determined whether the vehicle 10 is in a predetermined high-altitude environment. If the determination in S10 is affirmative, then in S20, it is determined whether the state-of-charge value SOC is less than a determination value SOC_jdg3. If the determination in S20 is affirmative, then in S30, power generation by the electric motor MG is prioritized over ensuring driving force for traveling. If the determination in S20 is negative, then in S40, it is determined whether the state-of-charge value SOC is less than a determination value SOC_jdg2. If the determination in S40 is positive, then in S50, operation of the air conditioner 50 is stopped. If the determination in S40 is negative, then in S60, it is determined whether the state-of-charge value SOC is less than a determination value SOC_jdg1. If the determination in S60 is affirmative, then in S70, the power consumption Pcmp of the compressor motor 60a is limited to less than a predetermined amount Pcmp_lmt, i.e., the cooling capacity of the air conditioner 50 is limited. If the determination in S10 is negative or if the determination in S60 is negative, then in S80 the cooling capacity of the air conditioner 50 is not limited. After S30, S50, S70, and S80 are executed, the process returns. Note that in S50, S70, and S80, securing driving force for traveling is prioritized over power generation by the electric motor MG.

[0035] According to this embodiment, when securing driving force for traveling is prioritized over power generation by the electric motor MG during engine running and the vehicle 10 is in a predetermined high-altitude environment, (a) if the state-of-charge value SOC of the main battery 40 charged with power generated by the electric motor MG is less than a criterion value SOC_jdg1, the power consumption Pcmp of the compressor motor 60a is limited to less than a predetermined amount Pcmp_lmt, (b) if the state-of-charge value SOC is less than a criterion value SOC_jdg2 that is lower than the criterion value SOC_jdg1, operation of the air conditioner 50 is stopped, and (c) if the state-of-charge value SOC is equal to or greater than the criterion value SOC_jdg1, the cooling capacity of the air conditioner 50 is not limited. In a high-altitude environment, if the state-of-charge value SOC of the main battery 40 has a margin of error, the cooling capacity of the air conditioner 50 is not limited. On the other hand, if the state of charge value SOC of the main battery 40 does not have a margin, the cooling capacity of the air conditioner 50 is limited or operation is stopped. In this way, the driving force for traveling is ensured and the cooling capacity of the air conditioner 50 is limited or operation is stopped only when necessary, so that a decrease in power performance and a decrease in comfort inside the vehicle are suppressed.

[0036] According to this embodiment, when the state of charge value SOC is less than the determination value SOC_jdg1 and greater than or equal to the determination value SOC_jdg2, the predetermined amount Pcmp_lmt is set to a lower value as the state of charge value SOC decreases. When the state of charge value SOC is less than the determination value SOC_jdg1 and greater than or equal to the determination value SOC_jdg2, the predetermined amount Pcmp_lmt is set to a lower value as the state of charge value SOC decreases, compared to when the predetermined amount Pcmp_lmt is a constant value. This makes it possible to limit the decrease in comfort in the vehicle cabin to a level corresponding to the state of charge value SOC.

[0037] According to this embodiment, the air conditioner 50 is operated by operating the electric compressor 60 using power stored in the main battery 40, and the cooling capacity is limited by limiting the power consumption Pcmp of the electric compressor 60. Limiting the power consumption Pcmp of the electric compressor 60 suppresses the rate of decrease Vdec of the state of charge value SOC of the main battery 40, thereby suppressing a decrease in power performance and a decrease in comfort inside the vehicle cabin. [Example]

[0038] 3 is a schematic diagram of a vehicle 110 equipped with an electronic control device 190 according to a second embodiment. The configuration of the vehicle 110 in this embodiment is substantially the same as the configuration of the vehicle 10 in the first embodiment, except that while the air conditioner 50 in the vehicle 10 is operated by an electric compressor 60, the air conditioner 150 in the vehicle 110 is operated by a mechanical compressor 160. Therefore, the following description will focus on the parts of this embodiment that are different from the first embodiment, and parts that are substantially the same in function as the first embodiment will be denoted by the same reference numerals and will not be described as appropriate.

[0039] In the vehicle 110, the air conditioner 50, the electric compressor 60, and the electronic control unit 90 in the vehicle 10 described above are replaced by an air conditioner 150, a mechanical compressor 160, and an electronic control unit 190, respectively.

[0040] Air conditioner 150 is identical in configuration to air conditioner 50 except that it is powered by a mechanical compressor 160 .

[0041] The mechanical compressor 160 is a well-known mechanical air compressor driven by power from the engine 12. The engine 12 and the mechanical compressor 160 can be connected to each other via a belt transmission device 30 and an electromagnetic clutch C1. The belt transmission device 30 is a well-known belt-type transmission device including a crank pulley 20p connected to the crankshaft 20 of the engine 12 so as not to rotate relative to the crankshaft 20, a compressor pulley 32p connected to the intermediate transmission shaft 32 so as not to rotate relative to the crankshaft 20p, and a belt 34 wound between the crank pulley 20p and the compressor pulley 32p. The electromagnetic clutch C1 is a well-known electromagnetic clutch that can connect and disconnect the intermediate transmission shaft 32 and the input shaft 36 of the mechanical compressor 160.

[0042] When the electromagnetic clutch C1 is brought into an engaged state, the mechanical compressor 160 is operated using the power of the engine 12. When the electromagnetic clutch C1 is brought into a disengaged state, the operation of the mechanical compressor 160 is stopped. For example, the duty ratio α [%] (= engaged time / total time of engaged time and disengaged time) in the connection / disconnection control of the electromagnetic clutch C1 is controlled by the electronic control device 190, thereby controlling the operating state of the mechanical compressor 160 and making the cooling capacity of the air conditioner 150 variable.

[0043] The operating state of the mechanical compressor 160 also varies depending on the rotational speed Ne [rpm] of the engine 12. Therefore, in order to limit the cooling capacity of the air conditioner 150, for example, the relationship between the rotational speed Ne of the engine 12, the cooling capacity of the air conditioner 150, and the duty ratio α is controlled using a map that is predetermined experimentally or by design. The mechanical compressor 160 that drives the air conditioner 150 is a mechanical load (= load torque) on the engine 12. From another perspective, the mechanical load of the mechanical compressor 160 reduces the power generated by the electric motor MG, so it can also be considered as the reduction in the amount of power generated by the electric motor MG [kWh]. The duty ratio α can be considered as the mechanical load of the mechanical compressor 160, i.e., the reduction in the amount of power generated by the electric motor MG, and is therefore equivalent to the cooling capacity of the air conditioner 150 and corresponds to the "air conditioning capacity" in this invention.

[0044] The electronic control device 190 has substantially the same configuration as the electronic control device 90 in the first embodiment described above, but differs in the following respects. In the electronic control device 90 in the first embodiment, a control signal Scm for controlling the drive of the compressor motor 60a is output, but in the electronic control device 190, a control signal Sc1 for controlling the engagement and disengagement of the electromagnetic clutch C1 is output. The control function of the electronic control device 190 differs from that of the electronic control device 90 in that it controls the engagement and disengagement of the electromagnetic clutch C1 to limit the cooling capacity of the air conditioner 150 or stop its operation, but is otherwise the same. The electronic control device 190 corresponds to the "control device" in this invention.

[0045] When the state of charge value SOC is less than the determination value SOC_jdg1 and greater than or equal to the determination value SOC_jdg2 while the vehicle is traveling in a high-altitude environment, the electronic control unit 190 limits the duty ratio α to less than a predetermined value α_lmt. The predetermined value α_lmt is a value determined experimentally or by design so as to ensure driving force according to the state of charge value SOC of the main battery 40 while suppressing a decrease in comfort inside the vehicle, and corresponds to the "predetermined amount" in the present invention. When the state of charge value SOC is less than the determination value SOC_jdg2 while the vehicle is traveling in a high-altitude environment, the electronic control unit 190 disengages the electromagnetic clutch C1 (= the duty ratio α is 0[%]) and stops the operation of the air conditioner 150.

[0046] According to this embodiment, the same configuration as in the first embodiment is provided, and therefore the same effects as in the first embodiment are achieved.

[0047] According to this embodiment, the air conditioner 150 is operated by operating the mechanical compressor 160 connected to the engine 12, and the cooling capacity is limited by limiting the drive load of the mechanical compressor 160 on the engine 12. By limiting the drive load of the mechanical compressor 160, the power of the engine 12 can be used for driving force for traveling or for power generation by the electric motor MG by the amount of the limited drive load, and the rate of decrease Vdec of the state of charge value SOC of the main battery 40 is suppressed. As a result, a decrease in power performance is suppressed, and a decrease in comfort inside the vehicle is also suppressed.

[0048] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention can also be applied to other embodiments.

[0049] In the first and second embodiments, the "rotating electric machine" of the present invention is the electric motor MG having a motor function, but it may be a rotating electric machine without a motor function as long as it has a generator function. In such an embodiment, for example, the engine 12 is started by a starter motor.

[0050] In the first and second embodiments described above, the vehicles 10, 110 are hybrid vehicles that include a clutch K0 that connects and disconnects the engine 12, which is a power source, and the electric motor MG, and in which the power output from the power source is transmitted to the drive wheels 14. However, the present invention is not limited to such vehicles. The present invention is applicable to any vehicle that has an engine 12 and a "rotating electric machine" that is driven and rotated by the engine 12 to generate electricity, and that is capable of engine running using the engine 12 as a power source.

[0051] In the first and second embodiments described above, when the state-of-charge value SOC is less than the determination value SOC_jdg3 (≦SOC_jdg2) while the vehicle is traveling in a high-altitude environment, priority is given to generating electricity by the electric motor MG over ensuring the driving force for traveling. However, the present invention is not limited to this. For example, when the state-of-charge value SOC is less than the determination value SOC_jdg2 while the vehicle is traveling in a high-altitude environment, operation of the air conditioner 50, 150 may be stopped and priority may be given to generating electricity by the electric motor MG over ensuring the driving force for traveling. In this embodiment, steps S20 and S30 in the flowchart of FIG. 2 are omitted, and step S40 is executed after step S10 is executed.

[0052] In the first and second embodiments described above, "cooling capacity" has been exemplified as "air conditioning capacity" in the present invention, but the present invention is not limited to this and may also be "heating capacity" or "dehumidifying capacity." The heating capacity and dehumidifying capacity of the air conditioner 50, 150 are, for example, the power consumption Pcmp of the compressor motor 60a that drives the air conditioner 50, and the amount of heat taken into the passenger compartment and the amount of moisture removed by the air conditioner 50 per unit time are determined according to the power consumption Pcmp.

[0053] In the first and second embodiments described above, whether the vehicle 10, 110 is in a predetermined high-altitude environment is determined based on the atmospheric pressure APair around the vehicle 10, 110, but this is not limiting. For example, if the altitude of the location where the vehicle 10, 110 is traveling can be identified based on a car navigation device including information on latitude, longitude, and altitude, and host vehicle position information indicating the position of the vehicle 10, 110 on the Earth's surface or a map based on a GPS signal (orbital signal) transmitted by a GPS (Global Positioning System) satellite, or the like, it may be determined based on the altitude whether the vehicle is in a predetermined high-altitude environment.

[0054] It should be noted that the above-described embodiments are merely examples of the present invention, and the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art, without departing from the spirit of the present invention. [Explanation of symbols]

[0055] 10, 110: vehicle, 12: engine, 40: main battery (battery), 50, 150: air conditioner, 60: electric compressor, 90, 190: electronic control unit (control unit), 160: mechanical compressor, MG: electric motor (rotating electric machine), Pcmp: power consumption (air conditioning capacity), Pcmp_lmt: predetermined amount, SOC: state of charge value, SOC_jdg1: judgment value (predetermined first threshold), SOC_jdg2: judgment value (predetermined second threshold), α: duty ratio (air conditioning capacity), α_lmt: predetermined value (predetermined amount)

Claims

1. A control device for a vehicle including an engine, a rotating electric machine that is rotationally driven by the engine to generate electricity, and an air conditioner, When the vehicle is in a predetermined high altitude environment in which securing the driving force for driving is prioritized over power generation by the rotating electric machine during driving using the engine as a power source and the output of the engine is reduced due to low air density in the surrounding atmosphere and the cooling capacity of the air conditioner is not limited, and securing the driving force for driving and securing charging of the battery by power generation by the rotating electric machine are not compatible, if the state-of-charge value of the battery charged by power generated by the rotating electric machine is less than a predetermined first threshold for limiting the cooling capacity of the air conditioner in order to secure the driving force, the air conditioning capacity of the air conditioner is limited to less than a predetermined amount, if the state-of-charge value is lower than the first threshold and less than a predetermined second threshold for stopping operation of the air conditioner in order to secure the driving force, the operation of the air conditioner is stopped, and the air conditioning capacity of the air conditioner is not limited if the state-of-charge value is equal to or greater than the first threshold. A vehicle control device characterized by:

2. When the state of charge value is less than the first threshold value and equal to or greater than the second threshold value, the predetermined amount is set lower as the state of charge value decreases.

2. The vehicle control device according to claim 1.

3. When the air conditioner is operated by operating an electric compressor using the electric power stored in the battery, the air conditioning capacity is limited by limiting the amount of power consumed by the electric compressor.

3. A vehicle control device according to claim 1 or 2.

4. When the air conditioner is operated by the operation of a mechanical compressor connected to the engine, the air conditioning capacity is limited by limiting the driving load of the mechanical compressor on the engine.

3. A vehicle control device according to claim 1 or 2.

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