JP3624839B2 - Control device for hybrid vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a hybrid vehicle that travels by a plurality of drive sources, and particularly to improve fuel consumption.
[0002]
[Prior art]
There is known a control device for a hybrid vehicle that obtains information on a travel route from a navigation device, sets a target value of a remaining battery level according to the travel route, and determines an operating point of an engine and a motor (for example, JP-A-8-126116).
[0003]
[Problems to be solved by the invention]
However, in the conventional hybrid vehicle control device described above, the engine and motor operating points are switched to the charging side when the remaining battery level is lower than the target value, and charging is stopped when the remaining battery level is higher than the target value. The engine and motor operating points are simply switched to the engine side or the discharge side, and the efficiency of the engine and motor affected by the road environment and driving conditions of the driving route is not taken into consideration. There is a problem that is not suppressed to the minimum.
[0004]
An object of the present invention is to provide a control device for a hybrid vehicle that controls an engine and a motor so that the remaining amount of the battery becomes the target value while suppressing the fuel consumption amount in the travel route to the minimum.
[0005]
[Means for Solving the Problems]
The present invention will be described with reference to FIGS. 1 and 2 showing the configuration of an embodiment.
(1) The invention of claim 1 controls a hybrid vehicle that uses either one or both of the engine 2 and the motors 1 and 4 as a braking / driving force source and transfers electric power between the motors 1 and 4 and the battery 15. Applied to the device.
And vehicle speed detecting means 23 for detecting the vehicle speed, braking / driving force command value setting means 16 for setting a braking / driving force command value for the vehicle,When charging the batteryAn efficiency index that represents the efficiency of fuel useAs an SOC conversion efficiency index corresponding to the increase in battery charging power relative to the increase in fuelThe efficiency index setting means 16b to be set, the vehicle speed detection value, the braking / driving force command value, and theSOC conversionBased on the efficiency indicator,SOC conversionThe larger the efficiency indexHigh fuel efficiency when charging the batteryThe engine 2 and the operating point determination means 16c for determining the operating points of the motors 1 and 4 are provided, thereby achieving the above object.
(2) The control device for a hybrid vehicle of claim 2A navigation device 33 for setting a travel route of the vehicle and detecting road environment information in the travel route is provided, and an efficiency index is set based on the road environment information of the travel route by the efficiency index setting means 16b.It is what I did.
(3) The hybrid vehicle control device according to claim 3 is:SOC detection means 25 for detecting the SOC of the battery 15, SOC prediction means 16 for predicting SOC at a specific point on the travel route based on the SOC detection value, and target SOC setting for setting a target SOC at the specific point Means 33c, and the efficiency index setting means 16b sets an SOC conversion efficiency index that matches the predicted SOC value at the specific point with the target SOC.It is what I did.
(4) The hybrid vehicle control device according to claim 4 is:Based on the route dividing means 33a that divides the travel route to the specific point, the road environment information of the travel route, and the SOC conversion efficiency index, the SOC change amount of each divided section of the travel route is predicted. SOC change amount prediction means 16, and the SOC prediction means 16 predicts the SOC at the specific point by integrating the predicted SOC change amount of each divided section with the current SOC detection value as an initial value. The SOC conversion efficiency index is converged by the efficiency index setting means 16b so that the predicted SOC value at the specific point substantially matches the target SOC.It is what I did.
(5) The hybrid vehicle control device according to claim 5 is:The SOC change amount predicting means 16 preliminarily stores SOC change amount data per unit travel distance when a travel pattern is assumed for each road environment and each travel pattern is traveled with various SOC conversion efficiency indexes. Predicting the amount of SOC change in each divided section based on the SOC conversion efficiency index and the road environment information of each divided sectionIt is what I did.
(6) The hybrid vehicle control device according to claim 6 is:Route dividing means 33a for dividing the traveling route to the specific point, and traveling condition predicting means 16a for predicting the vehicle speed and braking / driving force of each divided section based on road environment information of the traveling route, The SOC prediction unit 16 predicts the SOC at the specific point based on the SOC detection value, the SOC conversion efficiency index, the predicted vehicle speed, and the predicted braking / driving force, and the efficiency index setting unit 16b calculates the specific point. The SOC conversion efficiency index is converged so that the predicted SOC value at approximately matches the target SOCIt is what I did.
(7) The control device for a hybrid vehicle according to claim 7 is:Vehicle speed detecting means 23 for detecting the vehicle speed, accelerator opening detecting means 22 for detecting the depression amount of the accelerator pedal (hereinafter referred to as accelerator opening), and braking / driving force set in advance based on the vehicle speed and the accelerator opening A braking / driving force command value calculating means 16a for calculating a braking / driving force command value corresponding to the vehicle speed detection value and the accelerator opening detection value from a command value table, and by the efficiency index setting means 16b, When the difference between the detected vehicle speed value and the predicted vehicle speed exceeds a predetermined value, or when the difference between the braking / driving force command value and the predicted braking / driving force exceeds a predetermined value, the SOC conversion efficiency index is reset. SetIt is what I did.
(8) A control device for a hybrid vehicle according to claim 8 is:The SOC prediction means 16 predicts the SOC in each divided section based on the converged SOC conversion efficiency index, and the efficiency index setting means 16b determines the SOC detection value and the SOC predicted value in the divided section. The SOC conversion efficiency index is reset when the deviation exceeds a predetermined value.It is what I did.
(9) The hybrid vehicle control device according to claim 9 isAn upper / lower limit value setting means 16 for setting upper and lower limit values of the SOC is provided, and the SOC prediction means 16 predicts the SOC in each divided section based on the converged SOC conversion efficiency index, and the efficiency index setting means When the SOC predicted value of each of the divided sections exceeds the SOC upper / lower limit value by 16b, the SOC conversion efficiency index is corrected so that the SOC predicted value of each of the divided sections falls within the SOC upper / lower limit value. DoIt is what I did.
(10) The hybrid vehicle control device according to claim 10 is:The efficiency index setting means 16b resets the SOC conversion efficiency index when the predicted SOC value of each divided section approaches the SOC upper / lower limit value.It is what I did.
(11) A control device for a hybrid vehicle according to claim 11 is provided.The upper and lower limit value setting means 16 sets an upper limit value and / or a lower limit value for each of the divided sections or any point on the travel route.It is what I did.
(12) A control device for a hybrid vehicle according to claim 12 is:Upper / lower limit value setting means 16 for setting the upper and lower limit values of the SOC is provided, and when the detected SOC value approaches or reaches the SOC upper / lower limit value, the SOC conversion efficiency index is reset by the efficiency index setting means 16b.It is what I did.
(13) The control device for a hybrid vehicle of claim 13Vehicle speed storage means 16 for storing the vehicle speed of the travel route is provided, and the vehicle speed and braking / driving force of each of the divided sections are predicted by the travel condition prediction means 16a using the past vehicle speed storage value.It is what I did.
(14) A control device for a hybrid vehicle according to a fourteenth aspect includes:The navigation device 33 detects traffic congestion information on the travel route, and the efficiency index setting means 16b sets the efficiency index in consideration of the traffic congestion information.It is what I did.
(15) A hybrid vehicle control device according to claim 15 is provided.When the traffic information changes, the efficiency index is reset by the efficiency index setting unit 16b.It is what I did.
(16) A hybrid vehicle control device according to claim 16 is provided.The efficiency index setting means 16b sets the efficiency index in consideration of the gradient and altitude of the travel route.It is what I did.
(17) A control device for a hybrid vehicle according to claim 17 is provided.When the vehicle deviates from the travel route, the efficiency index is reset by the efficiency index setting means 16b.It is what I did.
[0006]
In the section of the means for solving the above-described problem, a diagram of an embodiment is used for easy understanding of the description. However, the present invention is not limited to the embodiment.
[0007]
【The invention's effect】
(1) According to the invention of claim 1,SOC conversionBy setting the efficiency index, the state of charge of the battery can be adjusted to a desired value.When the state of charge of the battery is high, the SOC conversion efficiency index is set to a large value, the amount of charge to the battery is reduced, the fuel required for battery charging can be saved, and the operating point with high fuel utilization efficiency can be realized. When the state of charge of the battery is low, the SOC conversion efficiency index can be set to a small value to reduce the fuel utilization efficiency, but it is possible to realize an operating point that increases the amount of charge to the battery. In other words, fuel usage efficiency can be prioritized over battery charging when the battery charge state is high, and battery charging can be prioritized over fuel utilization efficiency when the battery charge state is low. The fuel utilization efficiency can be improved while managing the state.
(2) According to the invention of claim 2,The efficiency index was set based on the road environment information of the driving route. Many hybrid vehicles regenerate the potential energy of the vehicle on the downhill and store it as electrical energy, but such vehicles allow for the regenerative energy when driving downhill based on the downhill information of the travel route. The fuel consumption can be reduced by increasing the efficiency index and suppressing the charge amount of the battery. In addition, the hybrid vehicle uses only the motor or the motor and engine as the drive source. However, to maintain the drive force for a long time in situations where uphills continue, keep the battery charge level high beforehand. Is desirable. In response to such demands, by reducing the efficiency index in anticipation of the amount of energy consumed when traveling uphill based on the uphill information of the vehicle's travel route, by increasing the battery charge state, The driving force on the uphill can be maintained for a long time. Thus, by using the road environment information of the travel route of the vehicle, the fuel utilization efficiency can be improved and the driving force characteristics can be improved.
(3) According to the invention of claim 3,The target SOC at the specific point can be reliably achieved.
(4) According to the invention of claim 4,Even on a route with a long distance to a specific point or a change point of the road environment to the specific point, for example, a travel route with many change points such as road type, congestion state, and gradient, the predicted SOC value at the specific point is sufficient for the target SOC. The SOC conversion efficiency index can be systematically and accurately obtained.
(5) According to the invention of claim 5,The amount of SOC change in each divided section can be predicted without predicting the vehicle speed and braking / driving force for each divided section based on the road environment information of the travel route, and the processing load on the control device can be reduced.
(6) According to the invention of claim 6,Even on a route with a long distance to a specific point or a change point of the road environment to the specific point, for example, a travel route with many change points such as road type, congestion state, and gradient, the predicted SOC value at the specific point is sufficient for the target SOC. The SOC conversion efficiency index can be systematically and accurately obtained.
(7) According to the invention of claim 7,By verifying the deviation between the vehicle speed detection value and the predicted vehicle speed, and the deviation between the braking / driving force command value and the predicted braking / driving force, an accurate SOC conversion efficiency index can be obtained, and the fuel utilization efficiency up to a specific point is improved. Thus, the target SOC at the specific point can be reliably achieved.
(8) According to the invention of claim 8,Detects SOC excess or deficiency caused by the SOC prediction error of each divided section or SOC excess or deficiency caused by the use of vehicle equipment and electrical components such as electric power steering and air conditioner powered by the same battery. It is possible to calculate an SOC conversion efficiency index in consideration of such SOC excess and deficiency. In general, the SOC is charged and discharged within a predetermined upper and lower limit value, for example, in the range of 20 to 80%, for battery protection. However, an SOC shift caused by this limitation can be detected, and an SOC conversion efficiency index considering the shift is used. It can be calculated. As a result, the fuel utilization efficiency up to the specific point can be reliably improved, and the actual SOC at the specific point can be brought close to the target SOC.
(9) According to the invention of claim 9,It is possible to improve the fuel utilization efficiency up to a specific point while keeping the SOC within the upper and lower limits, and to reliably achieve the target SOC at the specific point. .
(10) According to the invention of claim 10,It is possible to improve the fuel utilization efficiency up to a specific point while keeping the SOC within the upper and lower limits, and to reliably achieve the target SOC at the specific point.
(11) According to the invention of claim 11,The upper and lower limit values of the SOC can be set finely according to the road environment of the travel route, and the target SOC at the specific point can be reliably achieved while improving the fuel utilization efficiency up to the specific point.
(12) According to the invention of claim 12,When the SOC detection value approaches or reaches the SOC upper / lower limit value, the SOC conversion efficiency index is reset. In general, charging and discharging are performed so that the SOC falls within a predetermined upper and lower limit value for battery protection, but the SOC conversion efficiency index is not calculated in consideration of the upper and lower limit value limits of the SOC. After being restricted, even if the operating point of the engine and motor is adjusted according to the set SOC conversion efficiency index, the fuel utilization efficiency up to the specific point is sufficiently improved, and the SOC at the specific point is the target value. It is not always possible to approach. According to the thirteenth aspect of the present invention, even after the SOC is restricted, the fuel utilization efficiency up to the specific point can be further improved, and the SOC at the specific point can be brought close to the target value.
(13) According to the invention of claim 13,The vehicle speed and braking / driving force can be predicted flexibly corresponding to the driving characteristics of the driver, and the SOC at the specific point can be brought close to the target value while the fuel utilization efficiency up to the specific point is reliably improved.
(14) According to the invention of claim 14,An SOC conversion efficiency index is set in consideration of real-time traffic jam information collected by the navigation device. In general hybrid vehicles, when the battery charge state is maintained in a long traffic jam area, it is forced to operate with poor fuel consumption efficiency of the engine, but in anticipation of traffic jam in advance, the SOC conversion efficiency index is reduced and the SOC is increased. By doing so, it is possible to avoid operation with poor fuel utilization efficiency. Further, by setting the SOC conversion efficiency index in consideration of traffic jam information, the SOC at a specific point can be brought close to the target value.
(15) According to the invention of claim 15,The fuel utilization efficiency up to the specific point can be reliably improved in accordance with the change in the traffic congestion situation on the travel route, and the SOC at the specific point can be brought close to the target value.
(16) According to the invention of claim 16,Since the SOC conversion efficiency index is set in consideration of the change in the potential energy of the vehicle on the travel route, a more accurate index can be obtained and the fuel use efficiency up to the specific point can be improved while ensuring the specific point. The target SOC can be achieved.
(17) According to the invention of claim 17,Even when the vehicle deviates from the travel route set by the navigation device, it is possible to set an appropriate SOC conversion efficiency index according to the situation, while reliably improving the fuel utilization efficiency to the specific point, while at the specific point The target SOC can be achieved.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
<< First Embodiment of the Invention >>
FIG. 1 shows the configuration of an embodiment. In the figure, a thick solid line indicates a transmission path of mechanical force, and a thick broken line indicates a power line. A thin solid line indicates a control line, and a double line indicates a hydraulic system.
The power train of this hybrid vehicle includes a motor 1, an engine 2, a clutch 3, a motor 4, a continuously variable transmission 5, a speed reducer 6, a differential device 7, and drive wheels 8. A clutch 3 is interposed between the engine 2 and the motor 4, and the output shaft of the motor 1, the output shaft of the engine 2, and the input shaft of the clutch 3 are connected to each other, and the output shaft of the clutch 3 and the motor 4 The output shaft and the input shaft of the continuously variable transmission 5 are connected to each other.
[0009]
When the clutch 3 is engaged, the engine 2 and the motor 4 serve as a vehicle propulsion source, and when the clutch 3 is released, only the motor 4 serves as a vehicle propulsion source. The driving force of one or both of the engine 2 and the motor 4 is transmitted to the drive wheels 8 via the continuously variable transmission 5, the speed reducer 6, and the differential device 7. The continuously variable transmission 5 is supplied with pressure oil from the hydraulic device 9, and the belt is clamped and lubricated. An oil pump (not shown) of the hydraulic device 9 is driven by a motor 10.
[0010]
The motors 1, 4 and 10 are AC machines such as a three-phase synchronous motor or a three-phase induction motor, the motor 1 is mainly used for engine starting and power generation, and the motor 4 is mainly used for vehicle propulsion and braking. The motor 10 is for driving an oil pump of the hydraulic device 9. The motors 1, 4 and 10 are not limited to alternating current machines, and direct current motors can also be used. In addition, when the clutch 3 is engaged, the motor 1 can be used for vehicle propulsion and braking, and the motor 4 can be used for engine starting and power generation.
[0011]
The clutch 3 is a powder clutch and can adjust the transmission torque. The clutch 3 may be a dry single plate clutch or a wet multi-plate clutch. The continuously variable transmission 5 is a continuously variable transmission such as a belt type or a toroidal type, and the gear ratio can be adjusted steplessly.
[0012]
The motors 1, 4 and 10 are driven by inverters 11, 12 and 13, respectively. In the case where a DC motor is used for the motors 1, 4 and 10, a DC / DC converter is used instead of the inverter. The inverters 11 to 13 are connected to the main battery 15 through a common DC link 14, and the DC charging power of the main battery 15 is converted into AC power and supplied to the motors 1, 4, 10. The main battery 15 is charged by converting the AC generated power 4 into DC power. Since the inverters 11 to 13 are connected to each other via the DC link 14, the electric power generated by the motor during the regenerative operation can be directly supplied to the motor during the power running operation without going through the main battery 15. it can. As the main battery 15, various batteries such as a lithium-ion battery, a nickel-hydrogen battery, and a lead battery, and an electric double layer capacitor, so-called power capacitor, can be used.
[0013]
The vehicle controller 16 includes peripheral parts such as a microcomputer and a memory. The rotational speed and output torque of the motors 1, 4 and 10, the rotational speed and output torque of the engine 2, the engagement and release of the clutch 3, and the continuously variable transmission 5 The gear ratio is controlled.
[0014]
As shown in FIG. 2, the vehicle controller 16 includes a key switch 20, a brake switch 21, an accelerator sensor 22, a vehicle speed sensor 23, a battery temperature sensor 24, a battery SOC detector 25, an engine rotation sensor 26, a throttle sensor 27, and the like. Connected.
[0015]
The key switch 20 is turned on (closed) when the vehicle key is set to the ON position or the START position. The brake switch 21 detects the depression state of a brake pedal (not shown), and the accelerator sensor 22 detects the depression amount of the accelerator pedal (hereinafter referred to as accelerator opening). The vehicle speed sensor 23 detects the traveling speed of the vehicle, and the battery temperature sensor 24 detects the temperature of the main battery 15. The battery SOC detection device 25 detects the state of charge (SOC) of the main battery 15, and the engine rotation sensor 26 detects the rotation speed of the engine 2. Further, the throttle sensor 27 detects the throttle valve opening of the engine 2.
[0016]
Also connected to the vehicle controller 16 are a fuel injection device 30, an ignition device 31, a throttle valve control device 32, a navigation device 33, and the like of the engine 2. The controller 16 controls the fuel injection device 30 to adjust supply and stop of fuel to the engine 2 and the amount of fuel injection, and also controls the ignition device 31 to ignite the engine 2 and control the throttle valve adjustment device 33. Then, the torque of the engine 2 is adjusted.
[0017]
The navigation device 33 is a satellite navigation device that detects the current location and travel route with a GPS receiver, a self-contained navigation device that detects the current location and travel route with a gyrocompass, and a road-to-vehicle communication device that receives traffic information and road information such as VICS. It has a road map database, etc., searches for the optimum route to the destination, and guides passengers along the optimum route.
[0018]
The navigation device 33 also includes a route division function 33a, a road environment detection function 33b, and a target SOC determination function 33c realized by microcomputer software. The route division function 33a divides the guidance route to the destination. The road environment detection function 33b detects road curvature radii of divided sections, road gradients, presence / absence of intersections / tunnels / crossings, restriction information such as speed limits, and area information such as urban / mountainous roads. Further, the target SOC determination function 33c determines the target SOC (t_SOC) of the main battery 15 at the destination.
[0019]
The vehicle controller 16 includes a traveling condition prediction function 16a, an SOC conversion efficiency index calculation function 16b, and an engine / motor operating point calculation function 16c realized by microcomputer software. The traveling condition prediction function 16a predicts the vehicle speed and braking / driving force command value of each divided section based on the road environment of each divided section.
[0020]
The SOC conversion efficiency index calculation function 16b calculates an SOC conversion efficiency index SOCc used when determining the engine / motor operating point. The engine / motor operating point calculation function 16c calculates the operating points of the engine 2 and the motors 1 and 4 based on the SOC conversion efficiency index SOCc, the vehicle speed, and the braking / driving force command value.
[0021]
<< Calculation method of SOC conversion efficiency index SOCc >>
As described above, in the conventional hybrid vehicle control device, the operating point of the engine and the motor is switched to the charging side when the running battery SOC becomes lower than the target value, and when the SOC becomes higher than the target value, the charging stop side or Only the engine and motor operating points are switched to the discharge side, and the efficiency of the engine and motor affected by the road environment and driving conditions of the guide route is not taken into consideration, and the fuel consumption on the guide route is minimized. It is not limited to the limit.
[0022]
Therefore, in this embodiment, the engine 2 and the motors 1 and 4 are controlled so that the SOC of the main battery 15 becomes the target value while minimizing the fuel consumption in the guide path.
[0023]
First, the target SOC (t_SOC) at the destination is set. This target SOC (t_SOC) is the target value of the SOC at the destination, but the SOC of the main battery 15 does not necessarily have to be the target SOC (t_SOC) during the route to the destination. The operating points of the engine 2 and the motors 1 and 4 are not determined based on the target SOC (t_SOC). The target SOC (t_SOC) setting method at this destination includes a method of simply setting a constant value, for example 70%, regardless of the road environment, a method of determining according to the altitude of the destination, for example, a higher altitude. There is a method of setting a small target SOC (t_SOC) in the hope that the traveling energy at the time of going down can be collected in the main battery 15.
[0024]
Next, in this embodiment, in order to set the SOC of the main battery 15 at the destination as the target SOC (t_SOC) while minimizing the fuel consumption in the middle of the route to the destination, An SOC conversion efficiency index SOCc for determining the operating points of the engine 2 and the motors 1 and 4 in the course of the route is obtained by calculation.
[0025]
When this SOC conversion efficiency index SOCc is large, the charging power increase amount Δbat per unit fuel increase amount Δfuel for battery charging is increased, that is, the fuel use efficiency at the time of battery charging is increased. The engine / motor operating point is determined so as to perform charging only, and conversely, when the SOC conversion efficiency index SOCc is small, the engine / motor operating point is determined so that charging is performed even when the fuel utilization efficiency during battery charging is low. .
[0026]
With reference to FIG. 3, the calculation method of the SOC conversion efficiency index SOCc will be described.
A case where the traveling pattern to the destination is a pattern as shown in FIG. 3A will be described as an example. In FIG. 3a, the route to the destination is divided into n sections way (i) (i = 1, 2,..., N), and the vehicle speed p_vsp is based on the road environment for each section way (i). (I) and the braking / driving force command value p-tTd (i) are predicted. A method for predicting the vehicle speed p_vsp (i) and the braking / driving force command value p-tTd (i) will be described later. 3b to 3d determine the operating points of the engine 2 and the motors 1 and 4 by setting three types of fixed values SOCc_h, SOCc_m, and SOCc_l (where SOCc_h> SOCc_m> SOCc_l) as the SOC conversion efficiency index SOCc, respectively. Shows the minimum fuel consumption, charge / discharge amount, and SOC change.
[0027]
As described above, the SOC conversion efficiency index SOCc is an index that represents the fuel use efficiency during battery charging. Therefore, as is apparent from FIGS. 3b to 3d, the final SOC at the destination has the smallest value f_SOCc_h when the maximum value SOCc_h is set in the SOC conversion efficiency index SOCc, and the SOC conversion efficiency index SOCc. The value f_SOCc_l when the minimum value SOCc_l is set is the largest. That is, the actual SOC at the destination becomes smaller as the engine / motor operating point is set so as to charge only when the fuel utilization efficiency is high.
[0028]
Some value is set in the SOC conversion efficiency index SOCc, and an engine / motor operation described later is performed based on the predicted vehicle speed p_vsp (i) and the predicted braking / driving force command value p-tTd (i) of each divided section way (i). Temporary operating points of the engine 2 and the motors 1 and 4 are determined by the point determination method. Then, the time integration value p_bat (i) of the charge / discharge power Bat of each divided section way (i) is obtained, and the predicted battery charge / discharge power p_bat () of each divided section way (i) is determined using the current SOC (d_SOC) as an initial value. If i) is integrated over time, the predicted SOC (p_SOC (i)) in each divided section way (i) and the predicted SOC (p_SOC (n)) at the destination can be obtained.
[0029]
As described above, if the SOC conversion efficiency index SOCc is increased, the predicted SOC (p_SOC (n)) at the destination is decreased. Therefore, the initial value SOCc_0 is set in the SOC conversion efficiency index SOCc (SOCc = SOCc_0) If the predicted SOC (p_SOC (n)) at the destination is larger than the target SOC (t_SOC) at the destination when the predicted SOC (p_SOC (n)) is calculated, the SOC conversion efficiency index SOCc is
[Expression 1]
SOCc = SOCc+α (α> 0)
InincreaseAnd recalculate. Conversely, when the predicted SOC at the destination (p_SOC (n)) is smaller than the target SOC at the destination (t_SOC)), the SOC conversion efficiency index SOCc is
[Expression 2]
SOCc = SOCc−α (α> 0)
InReductionAnd recalculate.
[0030]
When the above calculation is repeated until the predicted SOC (p_SOC (n)) at the destination substantially coincides with the target SOC (t_SOC) at the destination, that is, the difference between the two becomes equal to or less than a predetermined value. SOCc_j (j is an integer of 0 or more) is determined as the final SOC conversion efficiency index SOCc. This calculation is performed when there is a new input or change of the destination, a departure from the guidance route, or a change in the traffic jam situation.
[0031]
Here, α is a fixed value that does not diverge the repetitive calculation. Alternatively, SOCc_0 may be determined according to traffic information or the like. For example, when the traffic congestion is severe and SOC (d_SOC) is small, SOCc_0 is set to a smaller value. Alternatively, in the case of a route that has traveled before, the initial value is a value that is corrected to be smaller as the current SOC (d_SOC) is smaller based on the SOCc at that time.
[0032]
<Engine / motor operating point determination method>
Next, a method for determining the engine / motor operating point when the clutch is engaged will be described with reference to FIGS. The operation points A, N, B, C, D, and E in FIG. 4 correspond to the operation points A, N, B, C, D, and E in FIG.
[0033]
When the calculation for determining the SOC conversion efficiency index SOCc is being performed, the temporarily set SOCc, the predicted vehicle speed p_vsp (i) and the predicted braking / driving force command value p_tTd (i) for each divided section way (i) Based on the above, temporary operating points of the engine 2 and the motors 1 and 4 are determined. On the other hand, when the determination of the SOC conversion efficiency index SOCc is completed and the vehicle is actually traveling toward the destination, the determined SOC conversion efficiency index SOCc (= SOCc_j), the vehicle speed detection value d_vsp, and the braking / driving force command Based on the calculated value d_tTd, a formal operating point when the engine 2 and the motors 1 and 4 are traveling is determined. The calculation value d_tTd of the braking / driving force command value is obtained by performing a table calculation from a braking / driving force command value table set in advance based on the vehicle speed detection value d_vsp and the accelerator opening detection value.
[0034]
In any of the operating point determinations, the operating point is determined so that charging is performed only when the SOC conversion efficiency index SOCc_j or SOCc increases and the fuel use efficiency during battery charging increases.
[0035]
FIG. 4 shows the engine / motor operating point when the vehicle speed is 50 km / h and the braking / driving force command value is 1000 N, and FIG. 5 shows the relationship between the engine / motor operating point and the battery charge amount at the same vehicle speed and braking / driving force command value. Indicates.
In FIG. 4, the thick line is the optimum fuel consumption line that connects the operating points at which the fuel consumption is minimized when the same engine output is obtained, and considers the efficiency of the engine 2, the motors 1, 4, and the continuously variable transmission 5. It has become a thing. The engine / motor operating point is always set on this bold line. Point A corresponds to the case where the vehicle is driven by the motors 1 and 4 as much as possible (for example, the vehicle is driven by supplying the maximum electric power that can be taken from the main battery 15 to the motors 1 and 4) and the shortage is covered by the output of the engine 2. It is an operating point. On the other hand, point E is an operating point when the vehicle is driven by the engine 2 and the motors 1 and 4 are driven to generate power in order to increase the charge amount of the battery 15.
[0036]
If the fuel supply amount to the engine 2 is increased at the operating point A where the main battery 15 is discharged, the charge / discharge amount of the main battery 15 becomes 0 at the point N, and further points B → C → D → The charge amount of the main battery 15 increases in the order of E. Incidentally, as shown in FIG. 5, the charge amount at point B is c_b [kW], the charge amount at point C is c_c [kW], the charge amount at point D is c_d [kW], and the charge amount at point E is c_e [ kW].
[0037]
With reference to the fuel supply amount at point A, the relationship between the charging power increase amount Δbat and the charging power Bat with respect to the fuel increase amount Δfuel is shown by curve (1) in FIG. Further, the curve (2) is obtained from the curve (1) to obtain the ratio (= Δbat / Δfuel) of the charging power increase amount Δbat to the fuel increase amount Δfuel, and this ratio is referred to as sensitivity S in this specification. These curves {circle around (1)} and {circle around (2)} are obtained in advance for each condition of vehicle speed and braking / driving force through experiments or the like.
[0038]
As shown in FIG. 5, the larger the SOC conversion efficiency index, the greater the sensitivity S is associated with. In this example, the sensitivity S is s170 for the SOC conversion efficiency index = 70%, the sensitivity S is s150 for the SOC conversion efficiency index = 50%, and the sensitivity S is s130 for the SOC conversion efficiency index = 30%. Respectively.
[0039]
Then, an engine / motor operating point that realizes charging power Bat with sensitivity S according to the SOC conversion efficiency index is calculated. For example, when the SOC conversion efficiency index is 70%, a point B1 that satisfies the sensitivity S = s170 on the sensitivity curve {circle around (2)} is obtained, and further, the point B on the fuel supply amount curve {circle around (1)} that realizes the sensitivity s170. 4 and the point B in FIG. 4 corresponding to this point B may be used as the operating point of the engine 2 and the motors 1 and 4. In addition, when there are two points on the curve {circle around (2)} satisfying the sensitivity S, a point having a large charge power Bat is adopted. If the point satisfying the sensitivity S is not on the curve (2), that is, if there is no driving point that can be charged with the sensitivity S under the current vehicle speed and braking / driving force conditions, the points shown in FIG. Let A be the operating point of engine 2 and motors 1 and 4.
The curves {circle around (1)} and {circle around (2)} differ depending on the conditions of the vehicle speed and the braking / driving force, so the maximum value of the sensitivity S also differs depending on the conditions of the vehicle speed and the braking / driving force. Therefore, when the SOC conversion efficiency index is large, an operating point that satisfies the sensitivity S can be obtained only under the conditions of limited vehicle speed and braking / driving force. On the other hand, when the SOC conversion efficiency index is small, an operating point that satisfies the sensitivity S can be obtained under a wide range of vehicle speed and braking / driving force conditions.
[0040]
As a result, the larger the SOC conversion efficiency index, the fewer the chances of charging the battery. Conversely, the smaller the SOC conversion efficiency index, the more charging opportunities. Further, the larger the SOC conversion efficiency index, the higher the fuel utilization efficiency at the time of charging, and the smaller the SOC conversion efficiency index, the lower the fuel utilization efficiency at the time of charging execution.
[0041]
In the above description, the sensitivity S corresponding to the SOC conversion efficiency index is obtained, the charging power Bat for realizing the sensitivity S is obtained, and the engine / motor operating point corresponding to the charging power Bat is obtained. Data in which the charging power Bat and the engine / motor operating point with respect to the SOC conversion efficiency index are associated may be stored, and the data may be read to obtain the charging power Bat and the engine / motor operating point. This facilitates the calculation of the engine / motor operating point.
[0042]
Further, with respect to the characteristic curve (1) in FIG. 5, taking into account the power consumption of the electrical components, the discharge efficiency of the main battery 15 when discharging to the left of the point N and the charging efficiency to the right of the point N are shown. It is good to relate in consideration of the charging efficiency of the main battery 15.
[0043]
The gear ratio of the continuously variable transmission 5 is adjusted to a gear ratio that realizes the vehicle speed and the rotational speed of the engine / motor operating point. Further, the torques of the motors 1 and 4 are distributed in advance, and a value capable of realizing the target braking / driving force command value by the motors 1, 4 and the engine 2 is calculated.
[0044]
The operating points of the clutch 3 are related in advance as shown in FIG. 6, and the engagement and release are controlled according to this relationship. When the clutch is disengaged, the rotational speeds of the engine 2 and the motor 1 coincide with each other, and the torque of the engine 2 and the converted value of the torque of the motor 1 around the engine shaft are constant. The operating points of the engine 2 and the motors 1 and 4 are determined by the method described with reference to FIG.
[0045]
In this embodiment, the above-described engine and motor operating point determination method is used for calculation of the SOC conversion efficiency index, and conversely, the above-described SOC conversion efficiency index is used for determination of the engine and motor operating point. Therefore, neither one can be calculated unless one is determined first. Therefore, as described above, in the calculation of the SOC conversion efficiency index SOCc, first, some value is set as the value of SOCc, in the above example, the initial value SOCc_0 is set to obtain a temporary operating point of the engine and the motor, and the SOC ( p_SOC (n)) is predicted. The calculation of the SOC conversion efficiency index SOCc is repeated until the predicted SOC (p_SOC (n)) at the destination matches the target SOC (t_SOC) using Formula 1 and Formula 2 using the predetermined value α, and the calculation has converged. Is determined as the final SOC conversion efficiency index SOCc.
[0046]
Then, actual operating points of the engine and the motor are determined based on the determined SOC conversion efficiency index SOCc. First, a braking / driving force command value d_tTd corresponding to the detected vehicle speed d_vsp and the detected accelerator opening d_acc is calculated from a table of braking / driving force command values set in advance based on the vehicle speed and the accelerator opening. Next, based on the SOC-converted efficiency index SOCc, the vehicle speed detection value d_vsp, and the calculated value d_tTd of the braking / driving force command value, a formal operating point when the engine and the motor are traveling is determined. The engine 2 and the motors 1 and 4 are controlled at this operating point.
[0047]
As a result, the operating point of the engine 2 and the motors 1 and 4 is determined using the SOC conversion efficiency index SOCc in the guidance route to the destination, and the fuel consumption in the guidance route to the destination is minimized. The SOC of the main battery 15 at the destination can be set to the target value t_SOC.
[0048]
7 and 8 are flowcharts showing the vehicle control program, and the operation of the first embodiment will be described with reference to these flowcharts. The vehicle controller 16 executes this control program every predetermined time. In step 1, the current location is detected. In the second and subsequent executions, the position in the divided section way (i) (i = 1 to n) is also detected. In the following step 2, it is confirmed whether or not there is a new input or change of the destination, a departure from the guidance route, or a change in the traffic condition. If there is any, the process proceeds to step 3; Proceed to In addition, the change of the traffic situation is obtained by a road-to-vehicle communication device such as VICS.
[0049]
When there is any new input or change of the destination, deviation of the guidance route, or change of the traffic congestion state, the guidance route to the destination is searched in step 3. In subsequent step 4, the guidance route to the destination is divided into n sections way (i) (i = 1 to n). This route division method can be used to classify points with distinctive features in the road environment, such as slope change points, intersections, road type change points, traffic jam start points, traffic jam end points, expressway tollgates, etc. There is a method of dividing the distance to the destination into n equal parts. When the distance to the destination is long, the route may be divided using a passing point on the guidance route to the destination as a temporary destination. In addition, as a method for determining the number of route divisions, there are a method for determining according to the degree of gradient change, the number of intersections, the road type, and a method for determining the number of divisions proportional to the distance to the destination.
[0050]
In step 5, road environment such as average gradient, intersection position, radius of curvature, altitude, etc. in each divided section way (i) is detected. In the subsequent step 6, as described above, the target SOC (t_SOC) at the destination is determined based on the road environment of each divided section way (i).
[0051]
In step 7, the vehicle speed p_vsp (i) and the braking / driving force command value p_tTd (i) in each divided section way (i) between the current location and the destination are predicted based on the road environment of each divided section way (i). . The vehicle speed p_vsp (i) is predicted as follows, for example. In the guidance route, the road speed limit is used as the predicted value. For example, a vehicle speed p_vsp (i) that predicts a vehicle speed p_vsp (i) such that the vehicle speed becomes 0 at a deceleration of 0.1G and returns to the cruising speed at an acceleration of 0.1G after 3 seconds of stopping at an intersection that makes a right or left turn. The vehicle speed p_vsp (i) is predicted based on the acceleration / deceleration and the passing speed corresponding to the vehicle speed. In addition, when traffic jam information is obtained from a road-to-vehicle communication device such as VICS, the vehicle speed p_vsp (i) is predicted such that the average vehicle speed decreases as the traffic jam in the traffic jam section increases. The braking / driving force command value p_tTd (i) of each divided section way (i) includes the driving force corresponding to the running resistance (air resistance component + rolling resistance component) corresponding to the vehicle speed p_vsp (i) and the speed of the previous section. A braking / driving force that is the sum of the braking / driving force corresponding to the acceleration / deceleration according to the difference and the braking / driving force corresponding to the acceleration / deceleration for absorbing the potential energy change of the vehicle according to the road gradient is set.
[0052]
When it is determined in step 14 that will be described later that the deviation between the prediction of the vehicle speed and the braking / driving force command value is large and step 7 is executed, the direction of deviation between the predicted value and the actual value is detected, and the direction of deviation is determined. Taking into account, the vehicle speed p_vsp (i) and the braking / driving force command value p-tTd (i) are re-predicted. For example, when the predicted vehicle speed p_vsp (i) during traveling tends to be higher than the actual vehicle speed, the predicted vehicle speed p_vsp (i) is set to a lower value, and the predicted braking / driving force command value p_tTd (i) during traveling is actually controlled. When it is smaller than the driving force command value, the predicted braking / driving force command value p_tTd (i) is set to a larger value. Alternatively, in the case of a route that the guidance route has taken before, the vehicle speed m_vsp (i) of the route section when the route has passed previously may be set as the predicted vehicle speed p_vsp (i), or the predicted vehicle speed p_vsp (i). And an internal division value of the previous vehicle speed m_vsp (i). However, in that case, it is necessary to store at least the vehicle speed m_vsp (i) in the route section that the vehicle has traveled before.
[0053]
In step 8, the current SOC (d_SOC) is detected, and in step 9, the SOC conversion efficiency index SOCc is calculated by the method described above. In step 10, based on the calculated SOC conversion efficiency index SOCc, the predicted vehicle speed p_vsp (i), and the predicted braking / driving force command value p_tTd (i), the SOC (p_SOC (i)) of each divided section way (i) is calculated. Predict. First, based on the SOC conversion efficiency index SOCc, the predicted vehicle speed p_vsp (i), and the predicted braking / driving force command value p_tTd (i), the engine 2 and the motors 1 and 4 in each divided section way (i) as described above. When the temporary operating point is obtained, the predicted battery charge / discharge power p_bat (i) in each divided section is obtained. Accordingly, when the current SOC (d_SOC) is used as an initial value and the predicted battery charge / discharge power p_bat (i) of each divided section way (i) is time integrated, the SOC (p_SOC (i)) of each divided section way (i) is obtained. Can be predicted.
[0054]
In step 11, the vehicle speed d_vsp is detected by the vehicle speed sensor 23, and in the subsequent step 12, the accelerator opening d_acc is detected by the accelerator sensor 22. In step 13, a braking / driving force command value d_tTd corresponding to the detected vehicle speed d_vsp and the detected accelerator opening d_acc is calculated from a table of braking / driving force command values set in advance based on the vehicle speed and the accelerator opening.
[0055]
In step 14, at the end of each divided section way (i), for example, average vehicle speed d_vsp (i) and average braking / driving force command value d_tTd (i), predicted vehicle speed p_vsp (i) and predicted braking / driving force of each divided section. It is determined whether or not the deviation from the command value p_tTd (i) is larger than each predetermined value. If it is larger, the process returns to Step 7, and if it is smaller than the predetermined value, the process proceeds to Step 15.
[0056]
As an index of deviation, for example, there is a method in which the sum ERR_1 of the square error of the vehicle speed and the square error of the braking / driving force command value is used as an index.
[Equation 3]
ERR_1 = Σ {(d_vsp (i) −p_vsp (i))²+ K1 (d_tTd (i) -p_tTd (i))²}
In the above equation, K1 is a constant, and Σ represents the total sum in i from the time when the previous predicted value was updated to the present time.
[0057]
Further, there is a method in which the power error exerted on the vehicle has a high correlation with the fuel consumption and charge / discharge power noted in this embodiment, and the square error ERR_2 of the power equivalent value (vehicle speed × braking / driving force) is used as an index. .
[Expression 4]
ERR_2 = Σ {(d_vsp (i) · d_tTd (i) −p_vsp (i) · p_tTd (i))²}
In the above equation, Σ represents the sum in i from the time when the previous predicted value was updated to the present time. If it is determined that the prediction of the vehicle speed and the braking / driving force command value is large and the process proceeds from this step to step 7, the direction of deviation between the predicted value and the actual value is detected, and the direction of deviation is taken into consideration. In step 7, the vehicle speed p_vsp (i) and the braking / driving force command value p_tTd (i) are re-predicted. For example, when the predicted vehicle speed p_vsp (i) during traveling tends to be higher than the actual vehicle speed, the predicted vehicle speed p_vsp (i) is set to a lower value, and the predicted braking / driving force command value p_tTd (i) during traveling is actually When it is smaller than the braking / driving force command value, the predicted braking / driving force command value p_Td (i) is set to a larger value. Alternatively, in the case of a route that the guidance route has passed before, the vehicle speed pattern m_vsp (i) of the route section when the route has passed previously may be set as the predicted vehicle speed p_vsp (i), or the predicted vehicle speed p_vsp (i). ) And the previous vehicle speed m_vsp (i). However, in that case, it is necessary to store at least the vehicle speed m_vsp (i) in the route section that the vehicle has traveled before.
[0058]
In step 15, it is determined whether or not the difference between the current SOC (d_SOC) and the predicted SOC (p_SOC (i)) is greater than a predetermined value at the end point of each divided section way (i). Returning to step 16, the process proceeds to step 16 if it is equal to or smaller than the predetermined value. As an index of deviation, for example, there is one as shown in the following equation.
[Equation 5]
ERR — 3 = (d_SOC−p_SOC (i))²
[0059]
In step 16, a formal operating point when the engine and the motor are running is calculated based on the convergence value SOCc_j of the SOC conversion efficiency index SOCc, the current vehicle speed detection value d_vsp, and the braking / driving force command value calculation value d_tTd. . At this time, when the detected SOC (d_SOC) is in the vicinity of the upper and lower limit values set in advance for protecting the main battery 15, the protection of the battery 15 is prioritized and the detected SOC is used instead of the SOC conversion efficiency index SOCc. It is assumed that calculation is performed using (d_SOC). In the following step 17, the torque of the engine 2, the torques of the motors 1 and 4, the gear ratio of the continuously variable transmission 5, and the engagement / release of the clutch 3 are controlled so as to realize the engine / motor operating point.
[0060]
When the navigation device 33 is not operating or when the destination is not set, the steps 8 → 11 → 12 → 13 → 16 → 17 of the flowcharts shown in FIGS. 7 and 8 are executed in this order. However, when the destination is not set but the navigation device 33 is operating, it is detected that the vehicle is traveling on a commuting route that has traveled in the past or a route that travels well every day. For example, a destination such as a commuting destination or a supermarket may be specified from the traveling information, and step 3 and subsequent steps may be executed.
[0061]
In calculating the SOC conversion efficiency index SOCc, the predicted SOC (p_SOC (i)) of all the divided sections way (i) is calculated, so that the predicted SOC (p_SOC (i)) in step 10 is calculated. As the calculation value, the value of each divided section where SOCc = SOCc_j in step 9 may be used.
[0062]
Thus, in the first embodiment, the guide route to the destination is divided, and the vehicle speed p_vsp and the braking / driving force command value p_tTd in each divided section of the guide route are predicted based on the road environment information of the navigation, Based on the predicted vehicle speed p_vsp of each divided section, the predicted braking / driving force command value p_tTd, and the SOC-converted efficiency index SOCc in which the initial value SOCc_0 of the battery SOC is set, the operating points of the engine and the motor with good fuel utilization efficiency are temporarily determined. Next, the SOC at the destination is predicted based on the temporary operation points of the engine and motor in each divided section and the current SOC detection value d_SOC, and the predicted SOC (p_SOC) at the destination is the target SOC (t_SOC) at the destination. The SOC-converted efficiency index SOCc is converged to the convergence value SOCc_j until it substantially coincides with. Then, the braking / driving force command value d_tTd is calculated from a preset braking / driving force command value table based on the vehicle speed detection value d_vsp and the accelerator opening detection value, and the vehicle speed detection value d_vsp and the braking / driving force command value are calculated. Based on the value d_tTd and the convergence value SOCc_j of the SOC conversion efficiency index, the final operating points of the engine and the motor are determined.
[0063]
According to the first embodiment, the SOC conversion efficiency index SOCc is introduced, the vehicle speed and the braking / driving force command value of the guidance route are predicted based on the road environment information detected by the navigation device, and at the destination In order to achieve the target SOC, the operating points of the engine and the motor with good fuel utilization efficiency are temporarily determined. Therefore, when the vehicle speed detection value to the destination and the calculated value of the braking / driving force command value match the predicted vehicle speed and the predicted braking / driving force command value, respectively, it is possible to minimize the fuel consumption to the destination. it can. Also, when actually driving with the engine and motor operating points determined, instead of the predicted vehicle speed and predicted braking / driving force command value, the official operating point is calculated using the calculated values of the vehicle speed detection value and braking / driving force command value. Since calculation is performed, even when the predicted vehicle speed and the predicted braking / driving force command value deviate from the actual values, the operating point with poor fuel utilization efficiency is not selected, and the fuel consumption is reduced even when the prediction deviates. The effect can be maintained.
[0064]
<< Second Embodiment of the Invention >>
Another calculation method of the SOC conversion efficiency index SOCc will be described. The configuration of the second embodiment is the same as the configuration shown in FIGS. 1 and 2, and illustration and description thereof are omitted.
[0065]
FIG. 9 and FIG. 10 are flowcharts showing a vehicle control program including another calculation method of the SOC conversion efficiency index. The operation of the second embodiment will be described with reference to these flowcharts. Steps that perform the same operations as those shown in FIG. 7 and FIG. 8 are given the same step numbers, and differences will be mainly described.
[0066]
The vehicle controller 16 executes this control program every predetermined time. After the current location is detected in step 1, the current SOC (d_SOC) is detected in step 8. In the following step 2, as described above, it is confirmed whether there is a new input or change of the destination, a departure from the guidance route, or a change in the traffic situation. If any, the process proceeds to step 3 and there is nothing. If so, go to Step 11.
[0067]
When there is any new input or change of the destination, deviation of the guidance route, or change of the traffic congestion state, the guidance route to the destination is searched in step 3. Next, in step 4, as described above, the guidance route to the destination is divided into m sections way (j) (j = 1 to m), and each section way (j) is further divided into p sections. Is divided into n (= m · p) sections way (i) (i = 1 to n). In subsequent step 5, road environment such as average gradient, intersection position, radius of curvature, altitude, etc. in each divided section way (j) is detected. In the subsequent step 6, as described above, the target SOC (t_SOC) at the destination is determined based on the road environment of each divided section way (j).
[0068]
In step 21, the upper and lower limit values of the SOC corresponding to the road environment for each section way (j) are set in consideration of the power performance of the vehicle. For example, as shown in FIG. 11, when an uphill is expected to continue for 5 km from a section way (k) in the middle of the route, the section way ( The SOC lower limit value in k) is set to 50%, and when the uphill continues for 10 km, the SOC lower limit value is set to 60%. In principle, the upper and lower SOC values of each divided section are 80% or less and 20% or more for battery protection as shown in FIG. Further, the upper and lower limit values of the SOC may be set over the entire section, or may be set for each section way (j). Furthermore, you may set with respect to the arbitrary points on a guidance route. Of course, only the upper limit value or only the lower limit value may be set.
[0069]
In step 7, as described above, the vehicle speed p_vsp (i) and the braking / driving force command value p_tTd () in each divided section way (i) between the current position and the destination based on the road environment of each divided section way (j). i) is predicted. The vehicle speed p_vsp (i) is predicted as follows, for example. In the guidance route, the speed limit of the section way (j) is set as the predicted value. Also, at an intersection, level crossing, or toll gate that makes a right or left turn, for example, a vehicle speed p_vsp (i) is predicted such that the vehicle speed becomes 0 at a deceleration of 0.1G and returns to the cruising speed at an acceleration of 0.1G after stopping for 3 seconds. In the curved road section, the vehicle speed p_vsp (i) is predicted based on the acceleration / deceleration and the passing speed according to the curvature of the road. In addition, when traffic jam information is obtained from a road-to-vehicle communication device such as VICS, the vehicle speed p_vsp (i) is predicted such that the average vehicle speed decreases as the traffic jam in the traffic jam section increases. On the other hand, in the braking / driving force command value p_tTd (i) of each divided section way (i), the driving force corresponding to the running resistance (air resistance component + rolling resistance component) corresponding to the vehicle speed p_vsp (i), the previous section, The braking / driving force that is the sum of the braking / driving force corresponding to the acceleration / deceleration according to the speed difference and the braking / driving force corresponding to the acceleration / deceleration for absorbing the potential energy change of the vehicle according to the road gradient is set.
[0070]
In step 9, the SOC conversion efficiency index SOCc is calculated by the method described above in the first embodiment. In step 10, based on the calculated SOC conversion efficiency index SOCc, the predicted vehicle speed p_vsp (i), and the predicted braking / driving force command value p_tTd (i), the SOC (p_SOC (i)) of each divided section way (i) is calculated. Predict. First, based on the SOC conversion efficiency index SOCc, the predicted vehicle speed p_vsp (i), and the predicted braking / driving force command value p_tTd (i), the engine 2 and the motors 1 and 4 in each divided section way (i) as described above. When the temporary operating point is obtained, the predicted battery charge / discharge power p_bat (i) in each divided section is obtained. Accordingly, when the current SOC (d_SOC) is used as an initial value and the predicted battery charge / discharge power p_bat (i) of each divided section way (i) is time integrated, the SOC (p_SOC (i)) of each divided section way (i) is obtained. Can be predicted.
[0071]
In step 22, it is confirmed whether the SOC (p_SOC (i)) of each predicted divided section way (i) exceeds the upper and lower limit values set in step 21. If not, go to Step 11. If the predicted SOC (p_SOC (i)) exceeds the upper and lower limit values, a correction calculation of the SOC conversion efficiency index SOCc is performed in step 23. For example, as shown in FIG. 12, when the predicted SOC (p_SOC (i)) exceeds the lower limit at the PA point on the way to the destination (1), it does not exceed the lower limit (2) The SOC-converted efficiency index SOCc is corrected by Equation 1 to be small until the line of On the contrary, when the predicted SOC (p_SOC (i)) exceeds the upper limit value, the SOC conversion efficiency index SOCc is corrected by the above formula 2 so as not to exceed the upper limit value. However, if both the upper limit value and the lower limit value are exceeded during the correction process, the SOC predicted value p_SOC (i) closer to the current location of the vehicle (the smaller value of i) is preferentially adopted, The SOC conversion efficiency index SOCc is corrected by Equation 1 or Equation 2 so as to be within the lower limit.
[0072]
Next, at step 24, the predicted SOC (p_SOC (i)) of each section way (i) falls within the SOC upper and lower limits, for example, the predicted SOC (p_SOC (i)) as shown in FIG. The point where the change curve is closest to the SOC upper / lower limit value, or the intersection “PA” between the change curve of the predicted SOC (p_SOC (i)) and the SOC upper / lower limit value is stored. At this time, since the predicted SOC (p_SOC (n)) at the destination of the line (2) does not match the target SOC (t_SOC), if the SOC conversion efficiency index SOCc calculated in step 23 is used to the destination, The actual SOC at the ground will not match the target SOC (t_SOC). Therefore, the SOC conversion efficiency index SOCc calculated in step 23 is used until the vehicle reaches the point PA, and after determining in step 26 described later that the vehicle has reached the point PA, the SOC conversion efficiency index is calculated in step 9. By recalculating the SOCc and re-determining the driving point of the vehicle based on the value, the actual SOC at the destination can be substantially matched with the target SOC (t_SOC).
[0073]
If there is no new input or change of the destination, departure from the guidance route, or change in the traffic congestion state, the vehicle speed d_vsp is detected by the vehicle speed sensor 23 in step 11, and the accelerator opening d_acc is detected by the accelerator sensor 22 in the following step 12. Is detected. In step 13, a braking / driving force command value d_tTd corresponding to the detected vehicle speed d_vsp and the detected accelerator opening d_acc is calculated from a table of braking / driving force command values set in advance based on the vehicle speed and the accelerator opening.
[0074]
In step 14, the average vehicle speed d_vsp (i) and the average braking / driving force command value d_tTd (i), the predicted vehicle speed p_vsp (i) and the predicted braking / driving force command of each divided section at the end point of each divided section way (j). It is determined whether or not the deviation from the value p_tTd (i) is larger than each determination reference value. If it is larger, the process returns to Step 7 to calculate the predicted vehicle speed p_vsp (i) and the predicted braking / driving force command value p_tTd (i). Recalculate. On the other hand, if the difference between the predicted value of the vehicle speed and the braking / driving force command value and the actual value is equal to or less than the determination reference value, the process proceeds to step 15. As the deviation index, the sum ERR_1 of the square error of the vehicle speed and the square error of the braking / driving force command value shown in Equation 3 is used, or the square error ERR_2 of the power equivalent value shown in Equation 4 is used. be able to. In step 15, it is determined whether or not the difference between the current SOC (d_SOC) and the predicted SOC (p_SOC (i)) is larger than the criterion value at the end point of each divided section way (i). Returning to 9, the SOC conversion efficiency index SOCc is recalculated. On the other hand, if the deviation between the predicted value and the actual value of the SOC is equal to or smaller than the determination reference value, the process proceeds to step 25. Note that, for example, ERR_3 shown in Equation 5 can be used as the deviation index.
[0075]
When the difference between the vehicle speed, the braking / driving force command value, and the predicted value of SOC and the actual value is small, the difference between the current SOC (d_SOC) in step 25 and the SOC upper and lower limit values set in step 21 is less than or equal to a predetermined value δSOC. Check whether or not. Here, an appropriate value for determining that the SOC has approached the upper and lower limit values is set as the predetermined value δSOC. When the current SOC approaches the upper and lower limit values, the process returns to step 9 to recalculate the SOC conversion efficiency index SOCc. On the other hand, when the current SOC is not close to the upper and lower limit values, the routine proceeds to step 26, where it is confirmed whether or not the vehicle has reached the point PA. Here, the point PA is a point where the current SOC (d_SOC) reaches the SOC upper and lower limit values set in step 21. When the point PA is reached, the process returns to step 9 to recalculate the SOC conversion efficiency index SOCc. On the other hand, if the point PA has not been reached, the process proceeds to step 16.
[0076]
In step 16, a formal operating point when the engine and the motor are running is calculated based on the convergence value SOCc_j of the SOC conversion efficiency index SOCc, the current vehicle speed detection value d_vsp, and the braking / driving force command value calculation value d_tTd. . In the following step 17, the torque of the engine 2, the torques of the motors 1 and 4, the gear ratio of the continuously variable transmission 5, and the engagement / release of the clutch 3 are controlled so as to realize the engine / motor operating point.
[0077]
As described above, in the second embodiment, the upper and lower limit values of the SOC corresponding to the road environment for each section way (i) are set in consideration of the power performance of the vehicle, and the SOC conversion efficiency index SOCc and each section are set. The predicted SOC (p_SOC (i)) of way (i) is calculated. When the predicted SOC (p_SOC (i)) of each section way (i) exceeds the upper and lower limit values of the SOC, the SOC conversion efficiency index SOCc is recalculated so as to be within the upper and lower limit values, The point PA where the change curve of the predicted SOC (p_SOC (i)) in each section way (i) is closest to the SOC upper / lower limit value, or the intersection PA between the change curve of the predicted SOC (p_SOC (i)) and the SOC upper / lower limit value Remember. When the engine / motor operating point is determined based on the SOC conversion efficiency index SOCc and the vehicle is traveling, if the current SOC (d_SOC) approaches the SOC upper or lower limit value or reaches the point PA, the subsequent SOC conversion The efficiency index SOCc is calculated again, the engine / motor operating point is determined based on the new SOC conversion efficiency index SOCc, and the vehicle continues to travel to the destination. Thereby, the target SOC at the destination can be achieved while improving the fuel utilization efficiency to the destination.
[0078]
<< Third Embodiment of the Invention >>
Another calculation method of the SOC conversion efficiency index SOCc will be described. The configuration of the third embodiment is basically the same as the configuration shown in FIGS. 1 and 2, but in the third embodiment, the vehicle speed and braking / driving force in each divided section up to the destination are set. The traveling condition prediction function 16a (see FIG. 2) for predicting the command value is unnecessary.
[0079]
FIGS. 13 and 14 are flowcharts showing a vehicle control program including another calculation method of the SOC conversion efficiency index. The operation of the third embodiment will be described with reference to these flowcharts. Steps that perform the same operations as those shown in FIG. 7 and FIG. 8 are given the same step numbers, and differences will be mainly described.
[0080]
The vehicle controller 16 executes this control program every predetermined time. In step 1, the current location is detected. In the following step 2, it is confirmed whether or not there is a new input or change of the destination, a departure from the guidance route, or a change in the traffic condition. If there is any, the process proceeds to step 3; Proceed to When there is any new input or change of the destination, deviation of the guidance route, or change of the traffic congestion state, the guidance route to the destination is searched in step 3. In the subsequent step 4, as described above, the guidance route to the destination is divided into m sections way (j) (j = 1 to m) using the characteristic points in the road environment as the dividing points. In step 5, road environment such as average gradient, intersection position, curvature radius, altitude, etc. in each divided section way (j) is detected, and in step 6, as described above, the road in each divided section way (j) detected. A target SOC (t_SOC) at the destination is determined based on the environment.
[0081]
Next, in step 8, the current SOC (d_SOC) is detected, and in the following step 31, the SOC conversion efficiency index SOCc is calculated as follows. First, a driving pattern is assumed for each road environment, and the driving pattern is stored in advance in a memory as SOC change amount data (MAP2DSOC) per unit distance when driving with the SOC conversion efficiency index SOCc. Then, the SOC change amount p_dSOC (j) corresponding to the SOC conversion efficiency index SOCc and the road environment for each section way (j) is calculated from this data (MAP2DSOC), and the current SOC (d_SOC) is an initial value. As a result, the predicted SOC (p_SOC (j)) of each section way (j) and the predicted SOC (p_SOC (m)) at the destination are obtained by integrating the SOC change amount p_dSOC (j) of each section way (j). . This calculation is performed until the predicted SOC (p_SOC (m)) at the destination substantially matches the target SOC (t_SOC) at the destination, and the SOC-converted efficiency index when the two are almost the same is obtained as the final index SOCc. To do.
[0082]
In step 11, the vehicle speed d_vsp is detected by the vehicle speed sensor 23, and in the subsequent step 12, the accelerator opening d_acc is detected by the accelerator sensor 22. In step 13, the braking / driving force command value d_tTd corresponding to the detected vehicle speed d_vsp and the detected accelerator opening d_acc is calculated from a braking / driving force command value table set in advance based on the vehicle speed and the accelerator opening.
[0083]
In step 32, it is determined whether or not the error of the SOC change amount (p_dSOC (j)) in each section way (j) is large. That is, for each end point of each section way (j), the actual SOC change amount (d_dSOC (k)) of the section way (k) passed immediately before is compared with the calculated SOC change amount p_dSOC (k). If is large, correct it. For example, a value ERR4 obtained by the following equation can be used as the deviation determination reference value.
[Formula 6]
ERR — 4 = (d_dSOC (k) −p_dSOC (k))²
When the deviation is large, the process returns to step 8 to recalculate the SOC conversion efficiency index SOCc, and when the deviation is small, the process proceeds to step 15.
[0084]
In step 15, it is determined whether or not the difference between the current SOC (d_SOC) and the predicted SOC (p_SOC (i)) is larger than the determination reference value at the end point of each divided section way (j). Returning to step 9, the process proceeds to step 16 if it is equal to or smaller than the determination reference value. As the determination reference value, the reference value ERR_3 can be used in Equation 3 above.
As an index of deviation shown, for example, there is the one shown in the following equation.
[0085]
In step 16, a formal operating point when the engine and the motor are running is calculated based on the convergence value SOCc_j of the SOC conversion efficiency index SOCc, the current vehicle speed detection value d_vsp, and the braking / driving force command value calculation value d_tTd. . At this time, when the detected SOC (d_SOC) is in the vicinity of the upper and lower limit values set in advance for protecting the main battery 15, the protection of the battery 15 is prioritized and the detected SOC is used instead of the SOC conversion efficiency index SOCc. It is assumed that calculation is performed using (d_SOC). In the following step 17, the torque of the engine 2, the torques of the motors 1 and 4, the gear ratio of the continuously variable transmission 5, and the engagement / release of the clutch 3 are controlled so as to realize the engine / motor operating point.
[0086]
The road environment information, SOC conversion efficiency index, and SOC change amount of the travel route are stored, and the SOC change amount for each section way (j) is predicted in consideration of the past travel route data. Also good. Thereby, it is possible to predict the SOC change amount for each more accurate section way (j).
[0087]
As described above, according to the third embodiment, assuming the driving patterns for each road environment, the SOC change amount data per unit driving distance when the driving patterns are driven with various SOC conversion efficiency indexes. Store in memory beforehand. Then, the SOC change amount p_dSOC (j) corresponding to the SOC conversion efficiency index SOCc and the road environment for each section way (j) is calculated from the SOC change amount data per unit travel distance, and the current SOC is calculated. By integrating the SOC change amount p_dSOC (j) of each section way (j) using (d_SOC) as an initial value, the predicted SOC (p_SOC (j)) of each section way (j) and the predicted SOC (p_SOC) at the destination are integrated. (M)). This calculation is executed until the predicted SOC (p_SOCm) at the destination substantially coincides with the target SOC (t_SOC) at the destination, and the SOC conversion efficiency index when the two almost coincide is set as the final index SOCc. When the engine / motor operating point is determined based on the SOC conversion efficiency index SOCc, the actual SOC change amount d_dSOC (k) of each section way (k) and the calculated SOC change amount p_dSOC (k If the deviation is large, the SOC conversion efficiency index (SOC) is corrected. Further, in each section way (j), the current SOC (d_SOC) is compared with the predicted SOC (p_SOC (i)), and when the deviation is larger than the determination reference value, the SOC conversion efficiency index (SOC) is corrected. . Thereby, the target SOC at the destination can be achieved while improving the fuel utilization efficiency to the destination.
[0088]
In the above embodiment, the ratio of the charging power increase amount Δbat to the fuel increase amount Δfuel (Δbat / Δfuel), that is, the sensitivity S is used as the SOC conversion efficiency index, but the SOC conversion efficiency index is limited to the sensitivity S. Not. For example, for a hybrid vehicle that controls power generation when the SOC is low and suppresses power generation when the SOC is high, the SOC itself may be used as the SOC conversion efficiency index. In this case, when there is a downhill of a predetermined distance or more on the traveling path of the vehicle, the target SOC may be corrected to be smaller than the detected SOC. Further, the SOC correction amount may be increased as the difference between the SOC detection value and the target SOC at the destination is larger.
[0089]
Note that in the braking / driving force automatic adjustment system that automatically adjusts the braking / driving force of the vehicle according to the situation on behalf of the driver, the “accelerator opening” in the above-described embodiment is controlled by the braking / driving force automatic adjustment system. By replacing the driving force command value, it is possible to obtain the same effect as that of the above-described embodiment.
[0090]
Further, in the above-described embodiment, the parallel hybrid traveling is realized by engaging the clutch 3, and the application example to the vehicle that also performs the series hybrid traveling by releasing the clutch 3 is shown. Alternatively, the present invention can be similarly applied to a vehicle that performs only series / hybrid driving.
[0091]
Furthermore, in the above-described embodiment, the continuously variable transmission has been described as an example. However, the transmission is not limited to the continuously variable transmission, and may be a stepped transmission. Further, the arrangement of the transmission is not limited to the above-described embodiment.
[0092]
Furthermore, the present invention can be applied to vehicles of all drive systems such as front wheel drive, rear wheel drive, and four wheel drive, and all forms of driving front wheels with an engine and driving rear wheels with a motor. It can be applied to a vehicle having a drive source form.
[0093]
In the above-described embodiment, the guidance route to the destination is searched, the target SOC (t_SOC) at the destination is set, the predicted SOC (p_SOC) at the destination is obtained, and the predicted SOC (p_SOC) is the target SOC. Although an example of setting the SOC conversion efficiency index SOCc that substantially matches (t_SOC) has been shown, an arbitrary intermediate point in the middle of the guide route is set instead of the destination, and a target SOC at the intermediate point is set At the same time, the predicted SOC at the intermediate point may be obtained, and the SOC conversion efficiency index SOCc may be set such that the predicted SOC at the intermediate point substantially matches the target SOC. In that case, the guidance route to the intermediate point is divided, and the SOC change amount, the predicted SOC, etc. are calculated for each divided route. The above-mentioned “specific point on the travel route” includes the destination of the guide route and any intermediate point on the guide route.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an embodiment.
FIG. 2 is a diagram illustrating a configuration of an embodiment following FIG. 1;
FIG. 3 is a diagram for explaining a method of calculating an SOC conversion efficiency index.
FIG. 4 is a diagram showing operating points of the engine.
FIG. 5 is a diagram showing charging power increase amount Δbat, charging power Bat, and sensitivity S with respect to engine fuel increase amount Δfuel;
FIG. 6 is a map for setting an operating point of a clutch.
FIG. 7 is a flowchart showing a vehicle control program according to the first embodiment.
FIG. 8 is a flowchart illustrating the vehicle control program according to the first embodiment following FIG. 7;
FIG. 9 is a flowchart showing a vehicle control program according to the second embodiment.
FIG. 10 is a flowchart illustrating the vehicle control program according to the second embodiment, following FIG. 9;
FIG. 11 is a diagram for explaining a method for setting an SOC upper / lower limit value;
FIG. 12 is a diagram for explaining a method of correcting an SOC conversion efficiency index.
FIG. 13 is a flowchart illustrating a vehicle control program according to a third embodiment.
FIG. 14 is a flowchart illustrating a vehicle control program according to the third embodiment, following FIG. 13;
[Explanation of symbols]
1 Motor
2 Engine
3 Clutch
4 Motor
5 continuously variable transmission
6 Reduction gear
7 Differential
8 Drive wheels
11-13 Inverter
14 DC link
15 Main battery
16 Vehicle controller
16a Travel condition prediction function
16b SOC conversion efficiency index calculation function
16c Engine / motor operating point calculation function
20 Key switch
21 Brake switch
22 Accelerator sensor
23 Vehicle speed sensor
24 Battery temperature sensor
25 Battery SOC detection device
26 Engine rotation sensor
27 Throttle sensor
30 Fuel injector
31 Ignition system
32 Throttle valve control device
33 Navigation device
33a Path division function
33b Road environment detection function
33c Target SOC decision function

Claims (17)

In a hybrid vehicle control device that uses one or both of an engine and a motor as a braking / driving force source and transfers power between the motor and the battery,
Vehicle speed detection means for detecting the vehicle speed;
Braking / driving force command value setting means for setting a braking / driving force command value to the vehicle;
An efficiency index setting means for setting an efficiency index representing fuel use efficiency at the time of battery charging as an SOC conversion efficiency index corresponding to the amount of increase in battery charge power relative to the amount of fuel increase ;
Based on the vehicle speed detection value, the braking / driving force command value, and the SOC conversion efficiency index, an operating point determination that determines the operating point of the engine and the motor with higher fuel use efficiency when charging the battery as the SOC conversion efficiency index is larger. And a control device for the hybrid vehicle. In the hybrid vehicle control device according to claim 1,
A navigation device for setting a travel route of the vehicle and detecting road environment information in the travel route;
The control apparatus for a hybrid vehicle, wherein the efficiency index setting means sets an efficiency index based on road environment information of the travel route . In the hybrid vehicle control device according to claim 2,
SOC detection means for detecting the SOC of the battery;
SOC prediction means for predicting SOC at a specific point on the travel route based on the SOC detection value;
A target SOC setting means for setting a target SOC at the specific point;
The control apparatus for a hybrid vehicle, wherein the efficiency index setting means sets an SOC conversion efficiency index that matches the predicted SOC value at the specific point with the target SOC . In the hybrid vehicle control device according to claim 3,
Route dividing means for dividing the travel route to the specific point;
SOC change amount prediction means for predicting the SOC change amount of each of the divided sections of the travel route based on the road environment information of the travel route and the SOC conversion efficiency index,
The SOC prediction means predicts the SOC at the specific point by integrating the predicted SOC change amount of each divided section with the current SOC detection value as an initial value,
The control apparatus for a hybrid vehicle, wherein the efficiency index setting means converges the SOC conversion efficiency index so that the predicted SOC value at the specific point substantially matches the target SOC . The hybrid vehicle control device according to claim 4,
The SOC change amount predicting means presupposes SOC change amount data per unit travel distance when each travel pattern is traveled with various SOC conversion efficiency indexes assuming a travel pattern for each road environment. An apparatus for controlling a hybrid vehicle, wherein an SOC change amount of each divided section is predicted based on a conversion efficiency index and road environment information of each divided section . In the hybrid vehicle control device according to claim 3 ,
Route dividing means for dividing the travel route to the specific point;
Travel condition prediction means for predicting the vehicle speed and braking / driving force of each of the divided sections based on road environment information of the travel route;
The SOC estimating means, the SOC detection value, the SOC conversion efficiency index predicts the SOC of the specific point on the basis of the predicted vehicle speed you and the predicted longitudinal force,
The control apparatus for a hybrid vehicle, wherein the efficiency index setting means converges the SOC conversion efficiency index so that the predicted SOC value at the specific point substantially matches the target SOC . In the hybrid vehicle control device according to claim 6 ,
Vehicle speed detection means for detecting the vehicle speed;
An accelerator opening detecting means for detecting an amount of depression of the accelerator pedal (hereinafter referred to as an accelerator opening);
The braking / driving force command value for calculating the braking / driving force command value corresponding to the vehicle speed detection value and the accelerator opening detection value from the braking / driving force command value table set in advance based on the vehicle speed and the accelerator opening. An arithmetic means,
When the deviation between the vehicle speed detection value and the predicted vehicle speed exceeds a predetermined value, or when the deviation between the braking / driving force command value and the predicted braking / driving force exceeds a predetermined value, the efficiency index setting means A control device for a hybrid vehicle , wherein an SOC conversion efficiency index is reset . In the hybrid vehicle control device according to claim 4 or 6 ,
The SOC prediction means predicts the SOC in each divided section based on the converged SOC conversion efficiency index,
The control apparatus for a hybrid vehicle, wherein the efficiency index setting means resets an SOC conversion efficiency index when a difference between the SOC detection value and the SOC predicted value in the divided section exceeds a predetermined value . In the hybrid vehicle control device according to claim 4 or 6 ,
An upper / lower limit value setting means for setting an upper / lower limit value of the SOC;
The SOC prediction means predicts the SOC in each divided section based on the converged SOC conversion efficiency index,
The efficiency index setting means, when the predicted SOC value of each divided section exceeds the SOC upper / lower limit value, converts the SOC conversion value so that the predicted SOC value of each divided section falls within the SOC upper / lower limit value. A control apparatus for a hybrid vehicle, wherein the efficiency index is corrected . The control apparatus for a hybrid vehicle according to claim 9 ,
The efficiency index setting means resets the SOC conversion efficiency index when the predicted SOC value of each divided section approaches the SOC upper and lower limit values . In the hybrid vehicle control device according to claim 9 or 10,
The upper / lower limit value setting means sets an upper limit value and / or a lower limit value for each of the divided sections or any point on the travel route . In the hybrid vehicle control device according to claim 3 ,
An upper / lower limit value setting means for setting an upper / lower limit value of the SOC;
The control apparatus for a hybrid vehicle, wherein the efficiency index setting means resets an SOC conversion efficiency index when the SOC detection value approaches or reaches the SOC upper / lower limit value . In the hybrid vehicle control device according to claim 6 ,
Vehicle speed storage means for storing the vehicle speed of the travel route;
The travel condition prediction means predicts the vehicle speed and braking / driving force of each of the divided sections using the past vehicle speed stored value . In the hybrid vehicle control device according to any one of claims 2 to 13 ,
The navigation device detects traffic congestion information on the travel route,
The control apparatus for a hybrid vehicle, wherein the efficiency index setting means sets an efficiency index in consideration of the traffic jam information . The hybrid vehicle control device according to claim 14 , wherein
The control apparatus for a hybrid vehicle, wherein the efficiency index setting means resets the efficiency index when the traffic jam information changes . In the control apparatus of the hybrid vehicle as described in any one of Claims 2-15 ,
The control apparatus for a hybrid vehicle, wherein the efficiency index setting means sets the efficiency index in consideration of the gradient and altitude of the travel route . In the hybrid vehicle control device according to any one of claims 2 to 16,
The control apparatus for a hybrid vehicle, wherein the efficiency index setting means resets the efficiency index when the vehicle deviates from the travel route .

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