Hybrid vehicle control method and hybrid vehicle control device

Abstract

To extend a distance allowing EV traveling in a hybrid vehicle.SOLUTION: In a step S1, a vehicle speed estimated value from a navigation system 15 is used to calculate a section traveling time from a current place to a start point of a first driving mode. In a step S6, the vehicle speed estimated value from the navigation system 15 is used to calculate an operation ratio of an internal combustion engine 9 within the traveling time from the current place to the start point of the first driving mode. In a step S7, the section traveling time is multiplied by the operation ratio of the internal combustion engine 9 to calculate a power generation possible time. In a step S2, the power generation possible time is multiplied by the amount of power generated by a power generator 8 per unit time to calculate an amount of power generation energy. In other words, in the step S2, the power generation possible time calculated by using the operation ratio of the internal combustion engine 9 is used to calculate the amount of power generation energy in which an actual vehicle speed is taken into consideration.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a hybrid vehicle having a driving mode in which it runs solely on the driving force of a motor generator. [Background technology]

[0002] Patent Document 1 discloses a hybrid vehicle that performs EV driving, in which the vehicle runs by driving the traction motor using only battery power without operating the internal combustion engine, and HEV driving, in which the vehicle runs using at least one of the internal combustion engine or the traction motor while the internal combustion engine is operating.

[0003] When the hybrid vehicle of Patent Document 1 travels from outside an area where EV driving is possible to a destination (base) within an area where EV driving is possible, it starts charging the battery while driving in HEV mode just before reaching the area where EV driving is possible, thereby increasing the battery's SOC in advance, and then switches to EV driving when it enters the area where EV driving is possible.

[0004] In Patent Document 1, pre-charging of the battery begins at a point a predetermined distance back from the border of the area where EV driving is possible, so that the battery's SOC will reach a predetermined target value when the vehicle reaches an area where EV driving is possible. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-32807 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, the predetermined distance is set on the assumption that a constant output of power generation will continue during pre-charging.

[0007] However, in hybrid vehicles, starting of the internal combustion engine may be prohibited depending on conditions such as vehicle speed, and when the vehicle reaches an area where EV driving is possible, the amount of charge in the battery may fall below the target, which could shorten the distance that EV driving can be achieved. [Means for solving the problem]

[0008] The hybrid vehicle of the present invention calculates a target SOC of the battery at the start of a first driving mode in which the vehicle travels by driving the drive wheels using only the driving force of the motor generator, an amount of energy that can be generated before reaching the start of the first driving mode, a first amount of energy consumed by the accessories before reaching the start of the first driving mode, and a second amount of energy consumed during travel until reaching the start of the first driving mode.

[0009] The hybrid vehicle uses the amount of generated energy, the first amount of consumed energy, and the second amount of consumed energy to predict a power generation start point on the driving route where the target SOC of the battery can be ensured, and starts generating power by driving the internal combustion engine from the power generation start point.

[0010] At least one of the generated energy amount, the first consumed energy amount, and the second consumed energy amount is calculated taking into consideration an actual vehicle speed of the hybrid vehicle. [Effects of the Invention]

[0011] The hybrid vehicle of the present invention can ensure a sufficient SOC in the battery at the start of the first driving mode, thereby increasing the driving distance in the first driving mode. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an explanatory diagram showing a schematic system configuration of a hybrid vehicle according to the present invention; [Figure 2] 10 is a timing chart showing a comparison between a case where the actual vehicle speed is taken into consideration when the vehicle speed prediction value is calculated and a case where the actual vehicle speed is not taken into consideration; [Figure 3] FIG. 2 is a block diagram showing an outline of charge / discharge schedule control according to the first embodiment. [Figure 4] 3 is an operation rate calculation map used when calculating an operation rate of an internal combustion engine; [Figure 5] FIG. 10 is a block diagram showing an outline of charge / discharge schedule control according to a second embodiment. [Figure 6] A stop time ratio calculation map used to calculate the vehicle stop time ratio. [Figure 7] FIG. 10 is a block diagram showing an outline of charge / discharge schedule control according to a third embodiment. [Figure 8] 10 is an acceleration / deceleration frequency calculation map used to calculate the acceleration / deceleration frequency of a vehicle. [Figure 9] FIG. 10 is a block diagram showing an outline of charge / discharge schedule control according to a fourth embodiment. [Figure 10] A power generation calculation map used to calculate the amount of power generated per unit time by a generator. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described in detail below with reference to the drawings.

[0014] FIG. 1 is an explanatory diagram that schematically shows the system configuration of a vehicle 1 to which the present invention is applied.

[0015] The vehicle 1 has a power generation unit 2, a battery 4 to which the power generated by the power generation unit 2 is supplied via a first inverter 3, a drive motor 6 to which the power from the battery 4 is supplied via a second inverter 5, and left and right drive wheels 7 connected to the drive motor 6.

[0016] The power generation unit 2 is mainly composed of a generator 8 as a first motor generator, and an internal combustion engine 9 for generating electricity that drives the generator 8. The power generation unit 2 can operate (start and stop) independently of the drive motor 6.

[0017] The generator 8 is, for example, a synchronous motor that uses a permanent magnet in the rotor. The generator 8 converts rotational energy generated in the internal combustion engine 9 into electrical energy (power) and is capable of supplying the power to the battery 4 via the first inverter 3. The generator 8 (power generating unit 2) is also capable of supplying power to the drive motor 6 via the first inverter 3 and the second inverter 5. The generator 8 also functions as a starter motor when the internal combustion engine 9 is started.

[0018] The battery 4 is, for example, a lithium-ion secondary battery, and is a secondary battery that can be charged as DC power with the power generated by the power generation unit 2 and the regenerative power generated by the drive motor 6. The battery 4 supplies the charged power to the drive motor 6 via a second inverter 5.

[0019] The first inverter 3 converts the power generated by the power generation unit 2 into DC power and supplies it to the battery 4 and the second inverter 5 .

[0020] The second inverter 5 converts the DC current output from the first inverter 3 and the DC power output from the battery 4 into AC power and supplies it to the drive motor 6. The second inverter 5 can also convert the AC power generated by the drive motor 6 into DC power and supply it to the battery 4.

[0021] The drive motor 6 corresponds to a motor generator or a second motor generator, and is, for example, a synchronous motor using a permanent magnet in the rotor. The drive motor 6 is the drive source for the vehicle 1, and drives the drive wheels 7 with AC power supplied via the second inverter 5. The drive motor 6 also functions as a generator when the vehicle 1 decelerates. The drive motor 6 can charge the battery 4 via the second inverter 5 with regenerative energy generated when the vehicle decelerates.

[0022] The vehicle 1 includes a first motor controller 11, a second motor controller 12, a battery controller 13, and a powertrain controller 14 as a control unit. These controllers 11, 12, 13, and 14 are connected by a CAN communication line that enables information exchange so that various data can be shared.

[0023] The first motor controller 11 controls the first inverter 3 to control the input / output torque of the generator 8 based on a command from the powertrain controller 14 .

[0024] The second motor controller 12 controls the first inverter 3 to control the input / output torque of the drive motor 6 based on a command from the powertrain controller 14 .

[0025] The battery controller 13 calculates the SOC of the battery 4 and transmits the calculated SOC to the powertrain controller 14.

[0026] The powertrain controller 14 is a well-known digital computer equipped with a CPU, ROM, RAM, and input / output interfaces, and controls the entire vehicle 1.

[0027] The powertrain controller 14 receives information from an on-board navigation system 15 and a dynamic map 16 on the cloud via communication means with the outside of the vehicle.

[0028] The navigation system 15 is in-vehicle static map information, and includes static information such as the shapes of roads and structures, lane information, etc., as well as information on the driving route from the current position of the vehicle 1 to the destination, and predicted vehicle speed values on this driving route.

[0029] The dynamic map 16 has dynamically changing information such as information on traffic regulations, accidents, congestion, vehicles, pedestrians, traffic signals, etc. on each road, and is capable of outputting statistics of actual vehicle speeds.

[0030] The vehicle 1 is a so-called series hybrid vehicle that runs by driving the drive motor 6 using power from the generator 8 and power from the battery 4. In other words, the vehicle 1 is a hybrid vehicle that has a mode in which power generation by the internal combustion engine 9 and vehicle driving can be achieved independently.

[0031] The vehicle 1 has a first driving mode (EV driving mode) in which the internal combustion engine 9 is stopped and the drive motor 6 is driven only by power from the battery 4, and a second driving mode (HEV driving mode) in which the internal combustion engine 9 is operated to generate electricity while driving the drive motor 6. The first driving mode is a so-called EV driving mode in which the vehicle travels only by the driving force of the drive motor 6.

[0032] When the SOC of the battery 4 becomes low while the vehicle is running, the powertrain controller 14 drives the internal combustion engine 9 to charge the battery 4.

[0033] The powertrain controller 14 controls the SOC of the battery 4 so that it is between a predetermined usable upper limit SOC (Usable SOC upper limit) and a predetermined usable lower limit SOC (Usable SOC lower limit).

[0034] For example, when the SOC of the battery 4 falls below a predetermined lower limit SOC as a result of EV driving (driving in the first driving mode), the powertrain controller 14 switches to HEV driving (driving in the second driving mode).

[0035] The powertrain controller 14 prohibits operation of the internal combustion engine 9 due to a noise and vibration request when the SOC of the battery 4 is within a predetermined upper and lower limit (a range that is less than the upper limit SOC for use and greater than the lower limit SOC for use) and the vehicle speed is less than a predetermined vehicle speed (a speed at which the internal combustion engine cannot be started).

[0036] When the powertrain controller 14 predicts, based on information from the navigation system 15, that the vehicle 1 will encounter traffic jams or travel around the home while traveling from the current location to the destination, and predicts that traveling in the first driving mode will be required for a predetermined section in accordance with requirements such as fuel efficiency and noise and vibration requirements, the powertrain controller 14 starts the internal combustion engine 9 and begins charging the battery 4 before the vehicle 1 reaches the start point of the first driving mode, so that the SOC of the battery 4 when the vehicle 1 reaches the start point of the first driving mode will be a target SOC at the start of the first driving mode (target SOC) that enables EV driving for the predetermined section (predetermined distance). The target SOC at the start of the first driving mode is a value that is equal to or lower than the upper limit SOC and higher than the lower limit SOC, and corresponds to the distance of the predetermined section in which EV driving is required.

[0037] That is, when the powertrain controller 14 predicts that the vehicle will travel in the first driving mode during driving, the powertrain controller 14 performs charge / discharge planning control to ensure the amount of energy required to carry out the predicted first driving mode. The charge / discharge planning control calculates the amount of energy to be generated, the amount of energy consumed by the accessories, and the amount of energy consumed during driving, and starts power generation before the start point of the first driving mode so that the SOC of the battery 4 will reach a predetermined target SOC at the start of the first driving mode (SOC at the start of EV driving) when the start point of the first driving mode is reached.

[0038] The amount of energy to be generated is the amount of energy that can be generated from the current location to the start point of the first driving mode, and is calculated using the predicted vehicle speed value. The amount of energy consumed by the auxiliary equipment as the first amount of energy consumption is the amount of energy consumed by the auxiliary equipment from the current location to the start point of the first driving mode, and is calculated using the predicted vehicle speed value. The amount of energy consumed for driving as the second amount of energy consumption is the amount of energy consumed for driving from the current location to the start point of the first driving mode, and is calculated using the predicted vehicle speed value. The sum of the first amount of energy consumption and the second amount of energy consumption is the amount of energy consumed to reach the start point of the first driving mode. Note that if the first amount of energy consumption is small enough to be ignored, control may be performed using only the second amount of energy consumption.

[0039] The powertrain controller 14 obtains from the navigation system 15 the start point of the first driving mode, information on the driving route from the current location to the start point of the first driving mode, and a predicted vehicle speed on the driving route. The powertrain controller 14 then calculates a target SOC (target SOC) at the start of the first driving mode to ensure in the battery 4 the electric power required to drive a predetermined section from the start point of the first driving mode in the first driving mode. Using the predicted vehicle speed, the powertrain controller 14 calculates the amount of power generation energy that can be generated before reaching the start point of the first driving mode, the amount of accessory energy consumed by the accessories before reaching the start point of the first driving mode, and the amount of energy consumed during driving until reaching the start point of the first driving mode. Next, the powertrain controller 14 predicts a power generation start point on the driving route that will ensure the target SOC at the start of the first driving mode in preparation for starting the first driving mode, using the amount of power generation energy, the amount of accessory energy consumed, and the amount of energy consumed during driving. The powertrain controller 14 then drives the internal combustion engine 9 from the power generation start point to start power generation.

[0040] The energy charge / discharge balance is significantly affected by the actual vehicle speed on the travel route. For example, if the actual vehicle speed is low, the internal combustion engine 9 may be prohibited from operating due to a noise and vibration request, power generation may not be performed as planned, and the target SOC at the start of the first operation mode may not be ensured in the battery 4 at the start point of the first operation mode.

[0041] Therefore, when calculating the amount of energy to be generated, the amount of energy consumed by the auxiliary devices, and the amount of energy consumed for traveling using the predicted vehicle speed value, the powertrain controller 14 takes into consideration the actual vehicle speed (actual vehicle speed pattern) when traveling along the travel route.

[0042] When taking into consideration the actual vehicle speed when traveling along the travel route, the actual vehicle speed is taken into consideration using a predicted vehicle speed value (predicted vehicle speed information, statistical average vehicle speed) available from the navigation system 15 as an alternative index.

[0043] In the first embodiment, the power generation time used to calculate the amount of power generation energy is calculated assuming that the operation ratio of the internal combustion engine 9 within the driving time to the start point of the first driving mode increases as the predicted vehicle speed value increases.

[0044] In other words, when calculating the amount of generated energy using the power generation time and the amount of power generation (power generation output) per unit time, the power train controller 14 calculates the power generation time assuming that the operating ratio of the internal combustion engine 9 within the driving time to the start point of the first driving mode becomes smaller as the predicted vehicle speed value becomes larger.

[0045] FIG. 2 is a timing chart comparing an example in which the actual vehicle speed is considered in the predicted vehicle speed value (the present invention) with an example in which the actual vehicle speed is not considered (a comparative example). The thin solid line in FIG. 2 represents the actual value in the comparative example, the thin dashed line in FIG. 2 represents the predicted control value in the comparative example, the thick solid line in FIG. 2 represents the actual value in the present invention, and the thick dashed line in FIG. 2 represents the predicted control value in the present invention. Note that the actual value is the actual value, and the predicted control value is a value predicted in advance based on information from the navigation system 15. For ease of explanation, the actual vehicle speed value and the predicted control value are assumed to be the same in the present invention and the comparative example. Time t1 is the timing at which the predicted control value of the SOC of the battery 4 becomes the predicted charge request threshold when the actual vehicle speed is considered in the predicted vehicle speed value (the present invention). When the actual vehicle speed is considered in the predicted vehicle speed value, the internal combustion engine 9 is started from time t1 so that the SOC of the battery 4 becomes the target SOC at the start of the first operation mode at the start of the first operation mode.

[0046] The predicted charge request threshold is a threshold set so that the SOC of the battery 4 becomes the target SOC at the start of the first operation mode at the start of the first operation mode. In other words, the predicted charge request threshold is the SOC of the battery 4 at the start of power generation.

[0047] Time t2 is the timing when the control predicted value of the SOC of the battery 4 becomes the predicted charge request threshold when the actual vehicle speed is not considered in the predicted vehicle speed value. When the actual vehicle speed is not considered in the predicted vehicle speed value, the internal combustion engine 9 is started from time t2 so that the SOC of the battery 4 becomes the target SOC at the start of the first operation mode at the start of the first operation mode.

[0048] That is, when the actual vehicle speed is taken into account in the predicted vehicle speed value (the present invention), the timing of starting the internal combustion engine 9 is earlier and the rate of increase per unit time of the predicted control value of the SOC of the battery 4 is smaller than when the actual vehicle speed is not taken into account in the predicted vehicle speed value. In other words, when the actual vehicle speed is taken into account in the predicted vehicle speed value (the present invention), the slope of the characteristic line indicating the predicted control value of the SOC of the battery 4 is smaller than when the actual vehicle speed is not taken into account in the predicted vehicle speed value.

[0049] Time t3 is the timing when the actual vehicle speed becomes equal to or lower than a predetermined vehicle speed (a vehicle speed at which the internal combustion engine cannot be started). However, the predicted control value of the vehicle speed is not equal to or lower than the vehicle speed at time t3 (a vehicle speed at which the internal combustion engine cannot be started). The internal combustion engine 9 stops at time t3. Therefore, the actual SOC of the battery 4 starts to decrease at time t3, but the predicted control value continues to increase after time t3.

[0050] Time t4 is the timing when the actual vehicle speed becomes greater than a predetermined vehicle speed (a vehicle speed at which the internal combustion engine cannot be started). The internal combustion engine 9 starts at time t4. Therefore, the actual SOC value of the battery 4 starts to increase after time t4.

[0051] Time t5 is the timing at which the vehicle reaches the starting point of the first driving mode. The time from time t5 to time t8 is the travel time for the section where driving in the first driving mode is scheduled.

[0052] When the actual vehicle speed is not taken into consideration (comparative example), the actual SOC of battery 4 at time t5 is significantly lower than the control predicted value because power generation was not possible between time t3 and time t4 and power generation was not possible as planned.

[0053] Therefore, when the actual vehicle speed is not taken into consideration (comparative example), the actual value of the SOC of the battery 4 becomes equal to or lower than the lower limit SOC at time t6, and the internal combustion engine 9 starts at time t6.

[0054] On the other hand, when the actual vehicle speed is taken into consideration (the present invention), the actual value of the SOC of battery 4 at time t5 is close to the predicted control value, even though power generation was not possible between time t3 and time t4 and power generation was not possible as planned. This is because by taking the actual vehicle speed into consideration, it is predicted that there will be sections where charging is not possible, and the timing to start power generation is made earlier than when the actual vehicle speed is not taken into consideration.

[0055] However, even when the actual vehicle speed is taken into consideration (the present invention), the actual SOC value of battery 4 at time t5 is smaller than the target SOC at the start of the first operating mode, so at time t7 the actual SOC value of battery 4 becomes a value below the usable lower limit SOC (Usable SOC lower limit), and the internal combustion engine 9 is started at time t7.

[0056] When the actual vehicle speed is taken into consideration (the present invention), the SOC of battery 4 at the start point of the first driving mode (time t5) is higher than when the actual vehicle speed is not taken into consideration (the present invention), and the driving distance in the first driving mode can be increased.

[0057] FIG. 3 is a block diagram showing an outline of the charge / discharge planning control according to the first embodiment, which is carried out in the powertrain controller 14. As shown in FIG.

[0058] In step S1, the vehicle speed prediction value from the navigation system 15 is used to calculate the travel time from the current location to the start point of the first driving mode.

[0059] In step S6, the operation rate of the internal combustion engine 9 during the travel time from the current location to the start point of the first driving mode is calculated using the predicted vehicle speed value from the navigation system 15. The operation rate of the internal combustion engine 9 is calculated using, for example, an operation rate calculation map such as that shown in FIG. 4. The operation rate of the internal combustion engine 9 is a coefficient indicating the extent to which the internal combustion engine 9 will stop under the vehicle speed conditions while traveling from the current location to the start point of the first driving mode, and the larger the predicted vehicle speed value, the larger the value (up to 1) becomes. In other words, the larger the operation rate of the internal combustion engine 9, the more difficult it is for the internal combustion engine 9 to stop under the vehicle speed conditions. The operation rate calculation map is stored, for example, in a ROM in the powertrain controller 14.

[0060] In step S7, the power generation available time is calculated by multiplying the section travel time calculated in step S1 by the operation rate of the internal combustion engine 9 calculated in step S6.

[0061] In step S2, the amount of power generation energy is calculated by multiplying the available power generation time calculated in step S7 by the amount of power generation per unit time of the generator 8. That is, in the first embodiment, the available power generation time calculated using the operation ratio of the internal combustion engine 9 is used to calculate the amount of power generation energy taking the actual vehicle speed into consideration.

[0062] In step S3, the auxiliary equipment consumption energy amount is calculated by multiplying the section travel time calculated in step S1 by the power consumed by the auxiliary equipment per unit time.

[0063] In step S4, the amount of energy consumed during traveling is calculated. The amount of energy consumed during traveling is expressed, for example, as the sum of the amount of energy consumed for air resistance, the amount of energy consumed for rolling resistance, the amount of energy consumed for gradient resistance, and the amount of energy consumed for acceleration resistance. The amount of energy consumed for air resistance, the amount of energy consumed for rolling resistance, and the amount of energy consumed for acceleration resistance are calculated, for example, using a predicted vehicle speed value from the navigation system 15. The amount of energy consumed for gradient resistance is calculated, for example, using the predicted vehicle speed value and gradient information from the navigation system 15.

[0064] In step S5, the amount of power generation energy calculated in step S2, the amount of auxiliary energy consumption calculated in step S3, and the amount of driving energy consumption calculated in step S4 are used to calculate (predict) the power generation start point (charging start position) on the driving route that will enable the target SOC at the start of the first driving mode to be secured in preparation for the start of the first driving mode.

[0065] The energy balance between the amount of energy generated, the amount of energy consumed by the auxiliary devices, and the amount of energy consumed while traveling can be estimated more accurately by taking into account the actual vehicle speed. This allows the vehicle 1 to more accurately calculate the power generation start point on the traveling route, ensuring a sufficient SOC in the battery 4 at the start point of the first driving mode, and ultimately increasing the traveling distance in the first driving mode.

[0066] The amount of generated energy can be expressed as the product of the power generation time (travel time to the start point of the first driving mode) and the power generation output (amount of power generated per unit time).The power generation time can also be expressed as the quotient of dividing the section distance (distance to the start point of the first driving mode) by the predicted vehicle speed.However, this method will result in an overcalculation of the power generation time if there is a condition that causes the internal combustion engine to stop operating that depends on the vehicle speed (for example, noise).

[0067] Therefore, in the first embodiment, the amount of energy to be generated can be predicted with high accuracy by taking into account the operating ratio of the internal combustion engine 9 during the driving time up to the start point of the first driving mode, and the power generation start point on the driving route can be calculated more accurately.

[0068] Another embodiment of the present invention will be described below. Note that the same components as those in the first embodiment described above are given the same reference numerals, and redundant explanations will be omitted.

[0069] 5 is a block diagram showing an outline of the charge / discharge schedule control of the second embodiment, which is performed in the powertrain controller 14. The vehicle 1 to which the charge / discharge schedule of the second embodiment is applied is the same as the vehicle 1 of the first embodiment described above.

[0070] In step S1, the vehicle speed prediction value from the navigation system 15 is used to calculate the travel time from the current location to the start point of the first driving mode.

[0071] In step S9, the vehicle speed prediction value from the navigation system 15 is used to calculate (compute) the stopping time ratio of the vehicle 1 during the driving time from the current location to the start point of the first driving mode. The stopping time ratio of the vehicle 1 is calculated, for example, using a stopping time ratio calculation map such as that shown in FIG. 6. The stopping time ratio of the vehicle 1 is a coefficient indicating how likely the vehicle 1 is to stop at an intersection or the like while driving from the current location to the start point of the first driving mode, and the larger the vehicle speed prediction value, the smaller the value (minimum 1). In other words, the larger the stopping time ratio of the vehicle 1, the more difficult it is for the vehicle 1 to stop. The stopping time ratio calculation map is stored, for example, in a ROM in the powertrain controller 14.

[0072] In step S10, the total elapsed time is calculated by multiplying the section travel time calculated in step S1 by the stop time ratio of the vehicle 1 calculated in step S9.

[0073] In step S2, the amount of generated energy is calculated by multiplying the section travel time calculated in step S1 by the amount of power generated by the generator 8 per unit time.

[0074] In step S3, the auxiliary equipment energy consumption amount is calculated by multiplying the total elapsed time calculated in step S10 by the power consumed by the auxiliary equipment per unit time. That is, in the second embodiment, the auxiliary equipment energy consumption amount is calculated taking into account the actual vehicle speed by using the total elapsed time calculated using the stop time ratio of the vehicle 1.

[0075] In step S4, the amount of energy consumed during traveling is calculated. The amount of energy consumed during traveling is expressed, for example, as the sum of the amount of energy consumed for air resistance, the amount of energy consumed for rolling resistance, the amount of energy consumed for gradient resistance, and the amount of energy consumed for acceleration resistance. The amount of energy consumed for air resistance, the amount of energy consumed for rolling resistance, and the amount of energy consumed for acceleration resistance are calculated, for example, using a predicted vehicle speed value from the navigation system 15. The amount of energy consumed for gradient resistance is calculated, for example, using the predicted vehicle speed value and gradient information from the navigation system 15.

[0076] In step S5, the amount of power generation energy calculated in step S2, the amount of auxiliary energy consumption calculated in step S3, and the amount of driving energy consumption calculated in step S4 are used to calculate (predict) the power generation start point (charging start position) on the driving route that will enable the target SOC at the start of the first driving mode to be secured in preparation for the start of the first driving mode.

[0077] In the second embodiment, the amount of energy consumed by the accessories is calculated taking into account the actual vehicle speed. Therefore, in the second embodiment, as in the first embodiment, the vehicle 1 can more accurately calculate the power generation start point on the driving route, ensuring a sufficient SOC in the battery 4 at the start point of the first driving mode, and ultimately increasing the driving distance in the first driving mode.

[0078] The amount of auxiliary energy consumption can be expressed as the product of the driving time (the driving time to the start point of the first driving mode) and the auxiliary power consumption (the amount of auxiliary power consumption per unit time). In addition, the driving time can be expressed as the quotient obtained by dividing the section distance (the distance to the start point of the first driving mode) by the predicted vehicle speed. However, this method will result in an undercalculation of the driving time when there are many stopping events such as intersections.

[0079] In the second embodiment, the amount of energy consumed by the auxiliary equipment can be predicted with high accuracy by taking into account the proportion of the time that the vehicle 1 is stopped during the driving time up to the start point of the first driving mode, and the power generation start point on the driving route can be calculated more accurately.

[0080] 7 is a block diagram showing an outline of the charge / discharge schedule control of the third embodiment, which is performed in the powertrain controller 14. The vehicle 1 to which the charge / discharge schedule of the third embodiment is applied is the same as the vehicle 1 of the first embodiment described above.

[0081] In step S1, the vehicle speed prediction value from the navigation system 15 is used to calculate the travel time from the current location to the start point of the first driving mode.

[0082] In step S11, the vehicle speed prediction value from the navigation system 15 is used to calculate (compute) an acceleration / deceleration frequency, which is an index representing the frequency of acceleration and deceleration of the vehicle 1 during the travel time from the current location to the start point of the first driving mode. The acceleration / deceleration frequency of the vehicle 1 is calculated, for example, using an acceleration / deceleration frequency calculation map such as that shown in FIG. 8. The acceleration / deceleration frequency of the vehicle 1 is a coefficient indicating how much (how many times) the vehicle 1 accelerates or decelerates at intersections, etc. while traveling from the current location to the start point of the first driving mode, and the larger the vehicle speed prediction value, the smaller the value (minimum 1). In other words, the larger the acceleration / deceleration frequency of the vehicle 1, the more frequently the vehicle 1 accelerates or decelerates. The acceleration / deceleration frequency calculation map is stored, for example, in a ROM in the powertrain controller 14.

[0083] In step S2, the amount of generated energy is calculated by multiplying the section travel time calculated in step S1 by the amount of power generated by the generator 8 per unit time.

[0084] In step S3, the auxiliary equipment consumption energy amount is calculated by multiplying the section travel time calculated in step S1 by the power consumed by the auxiliary equipment per unit time.

[0085] In step S4, the traveling energy consumption is calculated. The traveling energy consumption is expressed, for example, as the sum of the energy consumption for air resistance, the energy consumption for rolling resistance, the energy consumption for gradient resistance, and the energy consumption for acceleration resistance. The energy consumption for air resistance, the energy consumption for rolling resistance, and the energy consumption for acceleration resistance are calculated, for example, using a predicted vehicle speed value from the navigation system 15. The energy consumption for gradient resistance is calculated, for example, using a predicted vehicle speed value and gradient information from the navigation system 15. Here, in this third embodiment, the energy consumption for acceleration resistance is calculated taking into account the acceleration / deceleration frequency calculated in step S11. Specifically, in this third embodiment, the value obtained by multiplying the energy consumption for acceleration resistance calculated using the predicted vehicle speed value from the navigation system 15 by the acceleration / deceleration frequency calculated in step S11 is used as the energy consumption for acceleration resistance. In other words, the energy consumption for acceleration resistance in the third embodiment is obtained by multiplying the energy consumption for acceleration resistance in the first and second embodiments by the acceleration / deceleration frequency.

[0086] That is, in the third embodiment, the amount of energy consumption for acceleration resistance calculated using the acceleration / deceleration frequency of the vehicle 1 is used to calculate the amount of energy consumption for traveling taking the actual vehicle speed into consideration.

[0087] In step S5, the amount of power generation energy calculated in step S2, the amount of auxiliary energy consumption calculated in step S3, and the amount of driving energy consumption calculated in step S4 are used to calculate (predict) the power generation start point (charging start position) on the driving route that will enable the target SOC at the start of the first driving mode to be secured in preparation for the start of the first driving mode.

[0088] In the third embodiment, the amount of energy consumed during traveling is calculated taking into account the actual vehicle speed. Therefore, in the third embodiment, as in the first embodiment, the vehicle 1 can more accurately calculate the power generation start point on the traveling route, ensuring a sufficient SOC in the battery 4 at the start point of the first driving mode, and ultimately increasing the traveling distance in the first driving mode.

[0089] Since the actual vehicle speed profile is unknown, the amount of energy consumed while traveling is calculated by taking into consideration only information on intersections, etc. registered on a map, for example. However, this method will result in an undercalculation of the acceleration energy when the vehicle 1 accelerates after stopping at intersections, etc., when there are many stopping events.

[0090] In the third embodiment, the amount of energy consumed during driving can be predicted with high accuracy by taking into account the frequency of acceleration and deceleration during the driving time up to the start point of the first driving mode, and the power generation start point on the driving route can be calculated more accurately.

[0091] FIG. 9 is a block diagram showing an outline of the charge / discharge planning control according to the fourth embodiment, which is carried out in the powertrain controller 14. As shown in FIG.

[0092] In step S1, the vehicle speed prediction value from the navigation system 15 is used to calculate the travel time from the current location to the start point of the first driving mode.

[0093] In step S2, the section travel time calculated in step S1 is set as the power generation available time, and the amount of power generation energy is calculated by multiplying it by the amount of power generation per unit time of the generator 8.

[0094] In the fourth embodiment, the amount of power generated per unit time by the generator 8 is changed in accordance with the predicted vehicle speed. That is, in the fourth embodiment, the amount of power generated per unit time calculated using the predicted vehicle speed of the internal combustion engine 9 is used to calculate the amount of power generation energy taking the actual vehicle speed into consideration.

[0095] The amount of power generated per unit time by the generator 8 is calculated using, for example, a power generation amount calculation map as shown in Fig. 10. The amount of power generated per unit time by the generator 8 is a value according to the operating point of the internal combustion engine 9, and is set, for example, for three mutually different operating points, first to third. The first operating point is, for example, an operating point that prioritizes fuel efficiency. The second operating point is, for example, an operating point that prioritizes output, and is an operating point with higher rotation and higher load than the first operating point. The third operating point is, for example, an operating point that prioritizes noise and vibration performance, and is an operating point with lower rotation and lower load than the first operating point. The power generation amount calculation map is stored, for example, in a ROM in the powertrain controller 14.

[0096] When the vehicle speed prediction value is a low vehicle speed that is equal to or lower than a predetermined first prediction value, the internal combustion engine 9 is assumed to be operating at the third operating point, with emphasis on the sound and vibration performance of the vehicle 1, and the amount of power generated by the generator 8 per unit time is calculated.

[0097] When the vehicle speed prediction value is greater than a predetermined first prediction value and less than a predetermined second prediction value, the internal combustion engine 9 is assumed to be operating at a first operating point taking fuel efficiency into consideration, and the amount of power generated by the generator 8 per unit time is calculated.

[0098] If the vehicle speed predicted value is greater than a predetermined second predicted value, the internal combustion engine 9 is considered to be operating at a second operating point that prioritizes output, and the amount of power generated by the generator 8 per unit time is calculated. The amount of power generated per unit time when the internal combustion engine 9 is operating at the second operating point is greater than the amount of power generated per unit time when the internal combustion engine 9 is operating at the first operating point. The amount of power generated per unit time when the internal combustion engine 9 is operating at the third operating point is smaller than the amount of power generated per unit time when the internal combustion engine 9 is operating at the first operating point.

[0099] In step S3, the auxiliary equipment consumption energy amount is calculated by multiplying the section travel time calculated in step S1 by the power consumed by the auxiliary equipment per unit time.

[0100] In step S4, the amount of energy consumed during traveling is calculated. The amount of energy consumed during traveling is expressed, for example, as the sum of the amount of energy consumed for air resistance, the amount of energy consumed for rolling resistance, the amount of energy consumed for gradient resistance, and the amount of energy consumed for acceleration resistance. The amount of energy consumed for air resistance, the amount of energy consumed for rolling resistance, and the amount of energy consumed for acceleration resistance are calculated, for example, using a predicted vehicle speed value from the navigation system 15. The amount of energy consumed for gradient resistance is calculated, for example, using the predicted vehicle speed value and gradient information from the navigation system 15.

[0101] In step S5, the amount of power generation energy calculated in step S2, the amount of auxiliary energy consumption calculated in step S3, and the amount of driving energy consumption calculated in step S4 are used to calculate (predict) the power generation start point (charging start position) on the driving route that will enable the target SOC at the start of the first driving mode to be secured in preparation for the start of the first driving mode.

[0102] In the fourth embodiment, the amount of power generated per unit time by the generator 8 is determined taking into account the actual vehicle speed. Therefore, in the fourth embodiment, as in the first embodiment described above, the vehicle 1 can more accurately calculate the power generation start point on the travel route, and can ensure a sufficient SOC in the battery 4 at the start point of the first operation mode, thereby increasing the travel distance in the first operation mode.

[0103] The amount of power generated per unit time by the generator 8 varies depending on the operating point of the internal combustion engine 9. Therefore, if the amount of power generated per unit time by the generator 8 is constant regardless of the vehicle speed, there is a risk that the accuracy of predicting the amount of power generated will deteriorate if the operating point of the internal combustion engine 9 fluctuates.

[0104] In the fourth embodiment, the amount of power generation energy can be predicted with high accuracy by changing the amount of power generation per unit time of the generator 8 in accordance with the predicted vehicle speed value, and the power generation start point on the travel route can be calculated more accurately.

[0105] Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention.

[0106] For example, the first to fourth embodiments described above can be combined as appropriate. That is, for example, a first embodiment in which the amount of energy generated is calculated using a predicted vehicle speed value, a second embodiment in which the amount of energy consumed by auxiliary equipment is calculated using a predicted vehicle speed value, and a fourth embodiment in which the amount of power generated per unit time of generator 8 is determined using a predicted vehicle speed value may be combined and implemented.

[0107] In other words, the powertrain controller 14 may calculate at least one of the amount of energy generated, the amount of energy consumed by the auxiliary devices, and the amount of energy consumed during traveling, taking into account the actual vehicle speed.

[0108] The predicted vehicle speed may be one of the following: a statistical average vehicle speed in the navigation system 15; a speed limit for the road in the navigation system 15; a learned predicted value obtained by learning the actual vehicle speed history learned while traveling the same route; or a statistical output of the accumulated actual vehicle speeds from a dynamic map 16 that is composed of dynamically changing information such as traffic regulations, accidents, and congestion on each road.

[0109] The statistical average vehicle speed can take into account traffic congestion to some extent. The speed limit has a high coverage rate on the map data and can be used over a wide area. The learned prediction value can reflect the characteristics of the driver. The statistical output of the actual vehicle speed accumulation by the dynamic map 16 can respond with high accuracy to sudden changes such as accidents.

[0110] The hybrid vehicle to which the present invention is applicable is not limited to a series hybrid vehicle, but can also be applied to a hybrid vehicle (e.g., a series-parallel hybrid vehicle) that has a driving mode in which the internal combustion engine is stopped and the drive wheels are driven solely by the driving force of the drive motor.

[0111] The above-described embodiments relate to a control method for a hybrid vehicle and a control device for a hybrid vehicle. [Explanation of symbols]

[0112] 1...Vehicle 2...Power generation unit 3...First inverter 4. Battery 5...Second inverter 6...Drive motor 7...Drive wheels 8...Generator 9...Internal combustion engine 11...1st motor controller 12...Second motor controller 13...Battery controller 14...Powertrain controller 15...Navigation system 16...Dynamic Map

Claims

1. A control method for a hybrid vehicle having a battery that is charged with electric power generated by an internal combustion engine and that can supply electric power to a motor generator that drives drive wheels, and having a first driving mode in which the hybrid vehicle runs only on driving power from the motor generator, Obtaining information about the starting point and driving route of the first driving mode from static map information installed in the vehicle; In order to ensure that the battery has sufficient power to perform the first operating mode, Calculating a target SOC of the battery at a start point of the first operating mode; calculating an amount of power generation energy that can be generated before reaching a start point of the first operation mode; calculating a first amount of energy consumed by the auxiliary equipment until a start point of the first operating mode is reached; calculating a second amount of energy consumption consumed during the driving until the vehicle reaches a start point of the first driving mode; predicting a power generation start point on the travel route at which the target SOC of the battery can be ensured using the power generation energy amount, the first consumed energy amount, and the second consumed energy amount; drive the internal combustion engine from the power generation start point to start power generation; A control method for a hybrid vehicle, wherein at least one of the amount of generated energy, the first amount of consumed energy, and the second amount of consumed energy is calculated taking into consideration an actual vehicle speed when traveling along the travel route.

2. 2. The method of claim 1, wherein the actual vehicle speed is taken into account by utilizing a vehicle speed prediction value.

3. 3. The hybrid vehicle control method according to claim 2, wherein the predicted vehicle speed value is one of a statistical average vehicle speed in the static map information, a speed limit for the road in the static map information, a learned predicted value obtained by learning actual vehicle speed history, and a statistical output of actual vehicle speed accumulation using a dynamic map.

4. 4. The method for controlling a hybrid vehicle according to claim 2, wherein the power generation time used in calculating the amount of generated energy is calculated taking into account the operation rate of the internal combustion engine within the driving time up to the start point of the first driving mode.

5. 5. The method for controlling a hybrid vehicle according to claim 4, wherein the operation rate increases as the predicted vehicle speed value increases.

6. 6. The method for controlling a hybrid vehicle according to claim 4, wherein the amount of power generated per unit time using the internal combustion engine increases as the predicted vehicle speed value increases.

7. A control method for a hybrid vehicle according to any one of claims 2 to 6, wherein the driving time used when calculating the first energy consumption amount is calculated taking into account the proportion of stopping time within the driving time to the start point of the first driving mode.

8. 8. The method for controlling a hybrid vehicle according to claim 7, wherein the stopping time ratio decreases as the predicted vehicle speed value increases.

9. 9. The method for controlling a hybrid vehicle according to claim 2, wherein the second amount of consumed energy is calculated taking into consideration the frequency of acceleration and deceleration up to the start point of the first driving mode.

10. 10. The method for controlling a hybrid vehicle according to claim 9, wherein the frequency of acceleration / deceleration decreases as the predicted vehicle speed value increases.

11. A control device for a hybrid vehicle having a battery that is charged with electric power generated by an internal combustion engine and that can supply electric power to a motor generator that drives drive wheels, and having a first driving mode in which the vehicle runs using only the driving force of the motor generator, a control unit that obtains information on a start point of the first driving mode and a driving route from on-board static map information, calculates a target SOC of the battery at the start point of the first driving mode in order to ensure in the battery the electric power required to perform the first driving mode, calculates an amount of power generation energy that can be generated before reaching the start point of the first driving mode, calculates a first amount of consumed energy that will be consumed by an auxiliary device before reaching the start point of the first driving mode, calculates a second amount of consumed energy that will be consumed during driving until reaching the start point of the first driving mode, predicts a power generation start point on the driving route that will ensure the target SOC of the battery using the amount of generated energy, the first amount of consumed energy, and the second amount of consumed energy, and drives the internal combustion engine from the power generation start point to start power generation; The control unit is a control device for a hybrid vehicle that takes into consideration an actual vehicle speed when traveling along the travel route when calculating the amount of generated energy, the first amount of consumed energy, and the second amount of consumed energy.

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