Hybrid vehicles

Abstract

To reduce discomfort to occupants caused by engine vibration and noise associated with motoring. [Solution] A hybrid vehicle 1 comprising: a motor 2 that drives the vehicle using the power of a battery 6 and charges the battery 6 with regenerative power when the vehicle is decelerating; an engine 3 that can generate power to charge the battery 6 via a generator 5; a battery ECU 10 that acquires the charge rate of the battery 6; a navigation ECU 9 that acquires geographical information in the vehicle's driving area; and an HEV-ECU 11 that sets the target charge rate of the battery 6 to a predetermined first reference charge rate R1, and performs full-charge regeneration by consuming the regenerative power with motoring when the battery 6 is fully charged and regenerative power is generated, wherein the HEV-ECU 11 sets the target charge rate of the battery 6 to a second reference charge rate R2 which is lower than the first reference charge rate R1 when it detects that the vehicle is approaching a downhill road based on geographical information.

Description

[Technical Field]

[0001] This invention relates to a hybrid vehicle. [Background technology]

[0002] In recent years, hybrid vehicles have been developed that include an internal combustion engine, a generator driven by the internal combustion engine to produce electricity, a drive battery (storage battery) that can be charged by power supplied from the generator, and a drive motor that drives the drive wheels by power supplied from the drive battery or generator.

[0003] In hybrid vehicles like those described above, regenerative power generation is performed by the drive motor during vehicle deceleration, and the generated electricity is supplied to the drive battery for charging. At this time, if the drive battery is nearly fully charged, some vehicles perform so-called motoring, which involves suppressing the fuel supply to the internal combustion engine while forcibly driving the internal combustion engine with a generator (motor generator) to consume electricity, thereby enabling regenerative braking (full charge regeneration) (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2010-64679 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, in conventional technologies as described above, if vibrations and noise are generated by the forced operation of the internal combustion engine by such motoring in driving conditions where the internal combustion engine should be stopped, such as on a long downhill road, there is a risk that it may cause discomfort to the occupants.

[0006] This invention has been made in view of these problems, and its objective is to provide a control device for a hybrid vehicle that can reduce engine vibrations associated with motoring and the discomfort caused to occupants by such vibrations. [Means for solving the problem]

[0007] To achieve the above objective, the hybrid vehicle of the present invention comprises a motor that drives the vehicle using battery power and charges the battery with regenerative power when the vehicle is decelerating, an engine capable of generating power to charge the battery via a generator, a charge rate acquisition unit that acquires the charge rate of the battery, a geographic information acquisition unit that acquires geographic information in the vehicle's driving area, and a control device that sets the target charge rate of the battery to a predetermined first reference charge rate and performs full-charge regeneration by motoring which forces the engine to drive with the generator when the battery is fully charged and regenerative power is generated, wherein the control device sets the target charge rate of the battery to a second reference charge rate lower than the first reference charge rate when it detects that the vehicle is approaching a downhill road based on the geographic information. [Effects of the Invention]

[0008] The hybrid vehicle according to the present invention is a vehicle that performs full-charge regeneration, in which regenerative power is consumed by motoring when the battery is fully charged and regenerative power is generated. When the control device detects that the vehicle is approaching a downhill road based on geographical information, it sets the target charge rate of the battery to a second reference charge rate that is lower than the first reference charge rate. As a result, the hybrid vehicle can reduce the risk of full-charge regeneration occurring while driving downhill by reducing the battery charge level before the vehicle enters a downhill road. Therefore, the hybrid vehicle according to the present disclosure can reduce the discomfort caused to occupants by engine vibration and noise associated with motoring. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram showing the main components of the hybrid vehicle related to this disclosure. [Figure 2] This is a conceptual diagram illustrating the relative relationships of target charge rates set for hybrid vehicles. [Figure 3] This is a flowchart illustrating the control process for achieving the target charge level. [Figure 4] This is a conceptual diagram illustrating the calculation process for regenerative power generated on a downhill slope. [Figure 5] This is a conceptual diagram illustrating the charge rate control when driving on a memorized downhill road. [Modes for carrying out the invention]

[0010] The embodiments will be described in detail below with reference to the drawings. However, this disclosure is not limited to the content described below, and can be modified and implemented as such without altering its essence. Furthermore, the drawings used in describing the embodiments are schematic representations of the components, and may include partial emphasis, enlargement, reduction, or omission to enhance understanding, and may not accurately represent the scale or shape of the components.

[0011] Figure 1 is a block diagram showing the main components of the hybrid vehicle 1 according to this disclosure. The hybrid vehicle 1 includes a motor 2 (electric motor), reduction gear G, differential D, axle S, engine 3 (internal combustion engine), clutch 4, generator 5, battery 6, and inverter 7 as its driving drive system. The hybrid vehicle 1 also includes a PDU 8, navigation ECU 9, battery ECU 10, and HEV-ECU 11 as its driving control system.

[0012] The hybrid vehicle 1 travels by driving drive wheels W via at least one of a motor 2 and an engine 3, and can switch and set an EV travel mode, a series travel mode, or a parallel travel mode according to travel conditions as described later. Note that the vehicle is not limited to a hybrid vehicle (HEV), and may be a plug-in hybrid vehicle (PHEV) that can be externally charged and can output power externally.

[0013] The motor 2 is a traveling electric motor that can drive the drive wheels W via a reduction gear G, a differential D, and an axle S when electric power is supplied thereto. The motor 2 is also a motor generator (motor-generator) capable of regenerative power generation during deceleration traveling of the hybrid vehicle 1.

[0014] The engine 3 is an internal combustion engine that outputs power using fuel such as gasoline, and can drive the drive wheels W via a clutch 4, the differential D, and the axle S. The engine 3 can also generate electric power by driving a generator 5 with the generated power.

[0015] The clutch 4 is a switching mechanism that controls connection / disconnection of power transmission between the engine 3 and the differential D, and switches whether the power of the engine 3 is used for traveling drive of the vehicle or for power generation. That is, when the clutch 4 is engaged, the power of the engine 3 is transmitted to the drive wheels W via the differential D and the axle S, so that the hybrid vehicle can be driven to travel.

[0016] The generator 5 is a generator that can generate electric power by power output from the engine 3, and controls an amount of power generated within an output range of the engine 3 by controlling a power generation load. The generator 5 charges a battery 6 by supplying the electric power generated via an inverter 7 to the battery 6.

[0017] Battery 6 is an energy storage device consisting of a lithium-ion battery or a nickel-metal hydride battery, which outputs the power necessary to drive the motor 2 via the inverter 7, and also supplies power to various electrical equipment (not shown) installed in the hybrid vehicle 1.

[0018] The inverter 7 is a power conversion device that converts DC power to AC power, and can drive the motor 2 by supplying power output from at least one of the generator 5 and the battery 6 to the motor 2. In addition, the inverter 7 can charge the battery 6 by supplying power output from the generator 5 or regenerative power generated by the motor 2 when the vehicle is braking to the battery 6. Furthermore, when the battery 6 is nearly fully charged and there is no remaining regenerative power, the inverter 7 can generate regenerative power by having the generator 5 consume power through motoring, thereby creating regenerative power that is regenerated to the motor 2, thus performing full-charge regeneration.

[0019] The PDU8 is a Power Drive Unit that manages the state of the generator 5, calculates the power consumption of the generator 5, and notifies the HEV-ECU11 of this. In this embodiment, the PDU8 notifies the HEV-ECU11 of the amount of power consumed by the generator 5 through the full-charge regeneration described above, which uses the regenerative power from the motor 2 to run the engine 3.

[0020] The navigation ECU9 is a geographic information acquisition unit that acquires geographic information for the driving area of ​​the hybrid vehicle 1. It acquires the vehicle's position information using GPS (Global Positioning System) and manages the vehicle's driving position based on road information such as map data.

[0021] The battery ECU 10 is an electronic control device that manages the state of the battery 6 as a charge rate acquisition unit by monitoring parameters such as current, voltage, temperature, and charge rate (SOC) of the battery 6, and notifies the HEV-ECU 11 of the acquired parameters.

[0022] The HEV-ECU11 is an electronic control unit (ECU) that performs overall control of the hybrid vehicle 1, and is composed of an input / output unit 12, a memory unit 13, a central processing unit 14, and an external communication unit 15, among others.

[0023] The input / output unit 12 receives status signals and transmits control signals to various electrical equipment and auxiliary devices (not shown) connected via vehicle communication such as CAN (Controller Area Network), as well as to the respective components of the hybrid vehicle 1's drive system and drive control system. The storage unit 13 consists of a storage medium such as ROM, RAM, and non-volatile RAM, and stores all the programs and data necessary for controlling the hybrid vehicle 1, and in this embodiment, it stores information related to downhill roads corresponding to geographical information, as will be described in detail later. The central processing unit 14 is a CPU (Central Processing Unit) that processes various information of the hybrid vehicle 1 that changes moment by moment and executes program instructions stored in the storage unit 13. The external communication unit 15 is a wireless communication device that communicates with the outside of the hybrid vehicle 1 and sends and receives necessary information. The external communication unit 15 may be provided outside the HEV-ECU 11.

[0024] The HEV-ECU11 receives vehicle information from an accelerator sensor, brake sensor, and vehicle speed sensor (not shown) to understand acceleration requests and driving conditions, and can selectively switch between multiple driving modes based on this information. For example, the HEV-ECU11 can set an EV driving mode in which the motor 2 is driven using the power of the battery 6 while the engine 3 and generator 5 are stopped.

[0025] Furthermore, the HEV-ECU11 can set a series driving mode in which it allocates the power generated by the generator 5 using the power of the engine 3 to the drive control of the motor 2 via the inverter 7, and discharges or charges the battery 6 to any surplus or deficit of power generation.

[0026] Furthermore, the HEV-ECU11 can set up parallel driving, which involves engaging the clutch 4 to control the drive wheels W with the power of the engine 3, and, if necessary, driving the motor 2 with the power of the battery 6 to assist in driving.

[0027] With the above configuration, the hybrid vehicle 1 monitors the charge rate, which is the remaining power of the battery 6, sets a target charge rate that ensures that the power necessary for driving is not depleted as much as possible and that regenerative braking is possible on downhill roads, and drives while selecting a driving mode so that the charge rate of the battery 6 is maintained at the target charge rate.

[0028] Figure 2 is a conceptual diagram showing the relative relationship of target charge rates set for the hybrid vehicle 1. The target charge rate is used for switching driving modes and calculating the amount of power generated to restore the State of Charge (SOC) of the battery 6 in series mode. The HEV-ECU 11 sets the target charge rate to a predetermined first reference charge rate R1[%]. Here, the predetermined first reference charge rate R1[%] is a charge rate value that is arbitrarily set in advance as a certain level of SOC or higher so that the driver's acceleration request can always be met even when the output decreases due to a decrease in the SOC of the battery 6. In this embodiment, the first reference charge rate R1[%] is a fixed value, but it may be a variable value that is adjusted based on various information of the hybrid vehicle 1.

[0029] Furthermore, the HEV-ECU11 uses an emergency power generation charge rate R to prevent power depletion. E The following is set. HEV-ECU11 sets the charge rate of battery 6 to the emergency power generation charge rate R. E If the voltage falls below a certain level, the battery 6 is charged with electricity generated by the engine 3, regardless of the driving status of the hybrid vehicle 1.

[0030] Incidentally, in the case of hybrid vehicle 1, for example, when there is a long downhill slope, the battery 6 may reach full charge midway down the slope, and as described above, it may become necessary to consume regenerative power through motoring. In this case, hybrid vehicle 1 will perform full regeneration while driving in a state where the engine 3 should normally be stopped, which may cause discomfort to the occupants due to the vibration and noise of the engine 3.

[0031] Therefore, in the hybrid vehicle 1 according to this disclosure, as will be described in detail later, when it detects that it is approaching a downhill road, the target charge rate of the battery 6 is lowered to a second reference charge rate R2[%] which is lower than the first reference charge rate R1[%], thereby reducing the charge rate of the battery 6 before reaching the downhill road, and controlling it so that full regeneration does not occur as much as possible while driving downhill.

[0032] Figure 3 is a flowchart showing the control process for the target charge rate. The HEV-ECU11 controls the charge rate in preparation for long downhill roads by repeatedly executing the control procedure shown in Figure 3 while the hybrid vehicle 1 is in motion.

[0033] When the control is initiated, the HEV-ECU11 determines, based on acquired geographic information, whether the vehicle is approaching a downhill road where a change in the target charge rate is necessary (step S1). More specifically, the HEV-ECU11 determines, based on the information about the downhill road stored in the memory unit 13 along with the navigation map information, and the vehicle's position determined by GPS, whether the hybrid vehicle 1 is located within a predetermined distance range (X [km]) of the downhill road where charge rate control is necessary.

[0034] The HEV-ECU11 determines that the vehicle is not approaching a downhill road if it is traveling in a normal area such as an urban area where there are no long downhill roads, or if it is approaching a long downhill road but no information about that downhill road has been stored in the memory unit 13.

[0035] Furthermore, if the HEV-ECU11 determines that it is not approaching a downhill road, it determines whether the hybrid vehicle 1 has entered a downhill road that is not stored in the memory unit 13 (step S2). While driving in a normal area, the hybrid vehicle 1 drives in such a way that the battery 6's charge rate is maintained at the first reference charge rate R1[%]. Therefore, the HEV-ECU11 can determine whether the vehicle has entered a downhill road, for example, by whether the battery 6's charge rate has risen to or above the first reference charge rate R1[%].

[0036] In other words, if the HEV-ECU11 determines that the hybrid vehicle 1 is not approaching a downhill slope and is not entering a downhill slope that has not been stored in memory, it determines that there is no need to change the target charge rate and continues driving control while monitoring these factors.

[0037] On the other hand, if the HEV-ECU11 determines in step S2 that it has entered a downhill road that is not stored in the memory unit 13, it stores the vehicle's position in the memory unit 13 as the starting point Ps of the downhill road in the map information, and also (step S3) the distance from the starting point Ps of the downhill road to the ending point P E The amount of regenerative power generated during the drive up to that point is calculated as follows. Note that the HEV-ECU11 may determine the starting point Ps of the downhill road using GPS location information and map data.

[0038] Figure 4 is a schematic diagram illustrating the calculation process of regenerative power generated on a downhill slope. The HEV-ECU11 maintains the battery 6's charge level at a first reference charge level R1[%] until it reaches the downhill starting point Ps. It determines that the downhill starting point Ps has been reached when the battery 6's charge level rises to a value slightly higher than the first reference charge level R1[%] (R1+Δ[%]).

[0039] When downhill driving begins, the HEV-ECU11 determines whether or not full regeneration has started (step S4). More specifically, the HEV-ECU11 determines in step S4 that full regeneration will not start until the battery 6 reaches a charge rate of 100%, and then proceeds from the starting point Ps of the downhill road to the full charge point P in Figure 4.FULL As represented by the section up to this point, the increase in the state of charge of the battery 6 is monitored on the assumption that full charge regeneration will not be started.

[0040] Further, the HEV-ECU 11 determines a full charge point P at which the state of charge of the battery 6 reaches 100[%] FULL When the hybrid vehicle 1 travels up to the point, it is determined that full charge regeneration is started in step S4, and measurement of the amount of electric power generated by regeneration on the remaining downhill section is started (step S5). More specifically, the HEV-ECU 11 obtains the amount of electric power consumed by the generator 5 through motoring for full charge regeneration in a section from the start point Ps of the downhill section to an end point P E and measures a converted value E_gen [%] obtained by converting the amount of electric power into the state of charge.

[0041] Next, the HEV-ECU 11 continues monitoring the state of charge of the battery 6 while traveling on the downhill section with full charge regeneration, and determines whether or not the state of charge has decreased (step S6). If the HEV-ECU 11 determines that the state of charge of the battery 6 is maintained at 100[%], it continues monitoring the state of charge on the assumption that full charge regeneration is continuing due to traveling on the downhill section.

[0042] Subsequently, if the HEV-ECU 11 determines that the state of charge of the battery 6 has decreased to a value slightly lower than 100[%] (100-Δ[%]), it determines that the vehicle has reached the end point P of the downhill section E and judges that traveling using electric power from the battery 6 has been resumed, and ends the measurement of the converted value E_gen [%] of the power consumption amount in the generator 5 (step S7). Note that, when determining the start and end of a downhill section based on increases and decreases in the state of charge of the battery 6, the HEV-ECU 11 may set an observation period and a threshold value, such as that the SOC increases by Y% within a predetermined observation period X [min].

[0043] At this time, the HEV-ECU 11 calculates regenerative electric power (100-R1[%]) generated during traveling from the start point Ps of the downhill section to the full charge point P FULL and regenerative electric power from the full charge point P FULL to the end point P EBy adding the converted value E_gen[%] of the amount of electricity consumed by the generator 5 through full charge regeneration up to that point, it is possible to calculate the total charge rate that should be recovered by regenerative braking on the downhill road if there is sufficient regenerative capacity. For this reason, when the hybrid vehicle 1 travels down the downhill road on subsequent occasions, it is possible to suppress the occurrence of full charge regeneration while traveling down the downhill road by pre-decreasing the charge rate of the battery 6 at the starting point Ps of the downhill road to the second reference charge rate R2 shown by the calculation formula in Figure 4.

[0044] Therefore, the HEV-ECU11 performs a process to store the second reference charge rate R2, which is calculated along with the starting point Ps of the downhill road in the geographic information, in the storage unit 13 (step S8). After executing the process in step S8, the HEV-ECU11 terminates the target charge rate control process. In this way, each time the HEV-ECU11 enters an unknown downhill road that is not stored in the storage unit 13, it executes steps S2 to S8 to store the starting point Ps of the downhill road and its second reference charge rate R2 in the storage unit 13 for each of the multiple downhill roads.

[0045] Next, the process when the hybrid vehicle 1 travels down a downhill road after having stored information about the downhill road will be described. The HEV-ECU 11 monitors the approach to the downhill road stored in the storage unit 13 using GPS information and geographical information, and when it determines in step S1 that it has approached a downhill road, it obtains the current SOC of the battery 6 via the battery ECU 10 (step S9).

[0046] Furthermore, the HEV-ECU11 determines whether the current SOC of the battery 6 is equal to or greater than the second reference charge rate R2 stored as information about downhill roads (step S10). Here, if the storage unit 13 has information about multiple downhill roads stored in it, the HEV-ECU11 reads from the storage unit 13 the second reference charge rate corresponding to the downhill road that the hybrid vehicle 1 is approaching among the multiple downhill roads.

[0047] Next, if the HEV-ECU11 determines that the current SOC of battery 6 is already below the second reference charge rate R2, it determines that there is no need to change the target charge rate. At this time, if the driving mode is, for example, EV driving mode, the HEV-ECU11 may set it to series driving mode, thereby controlling the battery 6's charge rate so that it does not drop excessively from the second reference charge rate R2 on the way down the slope.

[0048] On the other hand, if the HEV-ECU11 determines that the current SOC of battery 6 is equal to or greater than the second reference charge rate R2, it changes the target charge rate to the second reference charge rate R2, thereby lowering the charge rate of battery 6 to the second reference charge rate R2 on the route to the downhill road (step S11). At this time, the HEV-ECU11 may set the driving mode to EV driving mode, thereby actively consuming the power of battery 6. In addition, the HEV-ECU11 may notify the driver that the SOC is lower than usual, for example, by displaying on the meter in the driver's seat that the target charge rate has been changed.

[0049] Figure 5 is a conceptual diagram illustrating the charge rate control when driving on a memorized downhill road. After entering point Px, which is X [km] away from the starting point Ps of the downhill road, the HEV-ECU 11 repeatedly executes the processes in steps S9 to S11 described above, thereby reducing the charge rate of the battery 6 to the second reference charge rate R2 during the drive until reaching the starting point Ps.

[0050] Furthermore, the HEV-ECU11 determines whether or not the hybrid vehicle 1 has entered a downhill slope based on geographical information and the vehicle's GPS information (step S12). The HEV-ECU11 may also determine whether or not the hybrid vehicle 1 has entered a downhill slope based, for example, on an increase in the charge level of the battery 6.

[0051] Then, when the HEV-ECU11 determines that the hybrid vehicle 1 has entered a memorized downhill slope, it changes the target charge rate to the first reference charge rate R1 because further power consumption will be impossible during downhill driving (step S13). As a result, the hybrid vehicle 1 drives downhill in EV driving mode while continuously performing regenerative braking. Furthermore, if the battery 6 drives in the same manner as when the downhill slope was memorized, the battery 6 will change the target charge rate to the end point P of the downhill slope when the hybrid vehicle 1 is reached. E The vehicle reaches a fully charged state when it reaches this point. The HEV-ECU11 terminates the target charge rate control process when it determines in step S12 that the hybrid vehicle 1 has not entered a downhill slope, or when it executes the process in step S13.

[0052] As a result, hybrid vehicle 1 will travel from the starting point Ps of the downhill road to the ending point P E Since the battery 6 does not reach full charge in the section up to that point, it is possible to prevent the generation of vibration and noise from the engine 3 due to full charge regeneration.

[0053] Furthermore, even if it is a downhill road that the hybrid vehicle 1 is traveling on for the first time, the HEV-ECU 11 can detect approach to the downhill road if it can obtain information about the downhill road from an external source via a communication line in step S1 (Yes in step S1), and may control the charge rate of the battery 6 using the obtained second reference charge rate. More specifically, an external server may be provided that receives information about downhill roads traveled by multiple vehicles of the same type as the hybrid vehicle 1 and manages it as a database. In this case, the HEV-ECU 11 can receive information about downhill roads around its own vehicle from the external server, detect the vehicle's approach to the downhill road, and obtain the second reference charge rate of the downhill road to compare it with the current SOC of the battery 6 (step S10) and change the target charge rate (step S11).

[0054] As described above, the hybrid vehicle 1 according to this disclosure is a vehicle that performs full-charge regeneration, consuming regenerative power through motoring when the battery 6 is fully charged and regenerative power is generated. When the HEV-ECU 11 detects that the vehicle is approaching a downhill road based on geographical information, it sets the target charge rate of the battery 6 to a second reference charge rate R2, which is lower than the first reference charge rate R1. As a result, the hybrid vehicle 1 can reduce the risk of full-charge regeneration occurring while driving downhill by reducing the charge level of the battery 6 before the vehicle enters a downhill road. Therefore, the hybrid vehicle 1 according to this disclosure can reduce the discomfort caused to occupants by the vibration and noise of the engine 3 associated with motoring.

[0055] Furthermore, the hybrid vehicle 1 uses geographical information to determine whether the vehicle is approaching a downhill slope based on whether it is located within a predetermined distance range (X [km]) of the downhill slope. This allows the hybrid vehicle 1 to determine approach to a downhill slope with relatively high accuracy.

[0056] Furthermore, with the hybrid vehicle 1, when driving downhill, setting it to EV driving mode allows the battery 6 to be charged by regenerative braking using the motor 2, and the vehicle can be driven in a state where the engine 3 is less likely to start, thereby reducing discomfort to the occupants caused by the vibration and noise of the engine 3.

[0057] Furthermore, the hybrid vehicle 1 may be set to EV driving mode when it is approaching a downhill road but has not yet entered the downhill road, and the charge level of the battery 6 is higher than the second reference charge level. This allows the hybrid vehicle 1 to efficiently consume the power of the battery 6 until it enters the downhill road, and reduces the risk of full regeneration occurring while driving downhill.

[0058] Furthermore, when the hybrid vehicle 1 is approaching a downhill slope but has not yet entered the downhill slope, the charge level of the battery 6 may be set to series driving mode if it is lower than the second reference charge level. This allows the hybrid vehicle 1 to control the battery 6's charge level so that it does not drop excessively from the second reference charge level R2 along the path to the downhill slope.

[0059] Furthermore, the hybrid vehicle 1 stores a second reference charge rate R2 for each of the multiple downhill roads corresponding to geographical information, and reads the second reference charge rate R2 of the downhill road where the vehicle's approach is detected from the storage unit 13 and sets it as the target charge rate. In this way, the hybrid vehicle 1 can set an appropriate second reference charge rate R2 for each downhill road it travels on.

[0060] Furthermore, the hybrid vehicle 1 stores in the memory unit 13 the second reference charge rate R2, which is calculated by subtracting the amount of electricity consumed by the generator 5 through full regeneration during downhill driving from the first reference charge rate R1, into a converted value E_gen[%]. This allows the hybrid vehicle 1 to set the second reference charge rate sufficiently accurately for each downhill road that has not been stored, further reducing the risk of full regeneration occurring when driving on each downhill road after the data has been stored.

[0061] Furthermore, hybrid vehicle 1 can acquire a second reference charge rate stored from previous downhill driving of other vehicles of the same model via a communication line and set it as the target charge rate. This allows the battery charge rate to be lowered in advance, reducing the risk of full regeneration occurring during driving, even on a downhill road being driven for the first time.

[0062] This concludes the description of the embodiments, but the hybrid vehicle 1 according to the present invention is not limited to the embodiments described above. For example, in the above embodiments, an example was given of assigning and storing a second reference charge rate to a downhill road in geographic information, but in the event that full regeneration is started when driving on the downhill road for the second time or later, or at the end point P of the downhill road EIf there is a significant margin in the charge level of battery 6, a learning function may be provided to update the second reference charge level R2 to an appropriate value. [Explanation of Symbols]

[0063] 1. Hybrid vehicle 2 motors 3 Engines 4 Clutch 5 Generators 6 batteries 7 Inverter 8 PDU 9 Navigation ECU 10 Battery ECU 11 HEV-ECU 12 Input / output section 13 Storage section 14 Central Processing Unit 15 External Communications Department Ps starting point P E End point P FULL Fully charged point R1 1st standard charging rate R2 2nd standard charging rate

Claims

1. A motor that drives the vehicle using battery power and charges the battery with regenerative power when the vehicle is decelerating, An engine capable of generating power to charge the battery via a generator, A charge rate acquisition unit that acquires the charge rate of the aforementioned battery, A geographic information acquisition unit that acquires geographic information in the vehicle's operating area, The system includes a control device that sets the target charge level of the battery to a predetermined first reference charge level, and performs full-charge regeneration by motoring, which forces the engine to drive with the generator when the battery is fully charged and regenerative power is generated, thereby consuming the regenerative power. A hybrid vehicle in which, when the control device detects that the vehicle is approaching a downhill road based on the geographic information, it sets the target charge rate of the battery to a second reference charge rate that is lower than the first reference charge rate.

2. The hybrid vehicle according to claim 1, wherein the control device determines whether the vehicle has approached the downhill road based on whether the vehicle is located within a predetermined distance range from the downhill road using the geographic information.

3. The hybrid vehicle according to claim 1 or 2, wherein the control device is set to an EV driving mode in which the vehicle is driven by the power of the motor with the engine stopped when the vehicle is traveling down the slope.

4. The hybrid vehicle according to claim 1 or 2, wherein the control device detects the vehicle approaching the downhill road, the vehicle is not traveling on the downhill road, and the charge level is higher than the second reference charge level, and sets the control device to an EV driving mode in which the vehicle is driven by the motor with the engine stopped.

5. The hybrid vehicle according to claim 1 or 2, wherein the control device detects the vehicle approaching the downhill road, the vehicle is not traveling on the downhill road, and the charge level is below the second reference charge level, and selects a series driving mode in which the vehicle is driven by the motor while the battery is being charged by the charging power of the engine.

6. The system includes a storage unit that stores the second reference charge rate for each downhill road corresponding to the geographical information, The hybrid vehicle according to claim 1 or 2, wherein the control device reads from the storage unit the second reference charge rate of the downhill slope where the vehicle's approach is detected among the plurality of downhill slopes and sets it to the target charge rate.

7. The hybrid vehicle according to claim 6, wherein the control device stores in the storage unit the second reference charge rate obtained by subtracting from the first reference charge rate the amount of electricity consumed by the generator by full regeneration during driving on the downhill road converted into the charge rate.

8. The hybrid vehicle according to claim 6, wherein the control device acquires the second reference charge rate stored when another vehicle of the same type as the vehicle has previously traveled down the downhill road, via a communication line, and sets it to the target charge rate.

Images