JP4051911B2 - Control device for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the fuel consumption of a hybrid vehicle that changes its vehicle weight while running on a guided route and to improve the braking/ driving force characteristics. SOLUTION: The weight of the vehicle on the guided route is set, and the state-of-charge (SOC) for each zone of the guided route is calculated based on the traffic information, vehicle weight, and the detected SOC value for each zone of the guided route; and the braking/driving force command value is set based on the detected vehicle speed value and the detected accelerator divergence value. The operating points of the engine and the motor are determined based on the detected vehicle speed value, the braking/driving force command value, and the calculated SOC value. By this means, the SOC after completing the guided route can be held within the target value or within a prescribed range, even for hybrid vehicles with large changes in vehicle weight caused by passengers boarding and alighting or goods being loaded and unloaded. The battery SOC may be planned and managed, taking into consideration the changes in vehicle weight, so that the braking/driving force through the motor is ensured and the braking/driving force characteristics are improved.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a hybrid vehicle, and more particularly, to improve fuel consumption and driving force characteristics when vehicle operation can be planned or predicted in advance.
[0002]
[Prior art]
2. Description of the Related Art A hybrid vehicle control device that obtains road information related to a guidance route from a navigation device in advance and controls an engine and a motor so that the guidance route can be driven with low fuel consumption based on the road information is known (for example, Japanese Patent Application Laid-Open No. 08-2008). -126116).
[0003]
The present applicant has proposed the control of a hybrid vehicle in which the SOC conversion index SOCc is introduced as a parameter representing the charge / discharge degree of the battery so as to improve the fuel consumption and driving force characteristics in the guide route travel ( (Japanese Patent Application No. 2001-31030). The SOC conversion index SOCc is associated in advance with the operating points of the engine and the motor such that the larger the value, the more the battery discharge amount (less charge amount) and the higher the fuel consumption efficiency of the engine. Therefore, if the SOC conversion index SOCc is set to a large value, an operation point with high fuel consumption efficiency can be realized although the amount of charge to the battery is small (the discharge amount is large), and conversely, the SOC conversion index SOCc is set to a small value. For example, it is possible to realize an operating point with low fuel consumption efficiency but with a large amount of charge to the battery (low amount of discharge). In particular, before driving the route, based on the road information of the guidance route obtained from the navigation device, the SOC conversion index SOCc that can realize low fuel consumption while maintaining the SOC within a predetermined range is calculated, and the actual accelerator during driving is calculated. By determining the operating points of the engine and the motor based on the opening degree, the actual vehicle speed, and the SOC-converted index SOCc, the fuel consumption at the time of traveling through the guide route is reduced. Further, the fuel consumption reduction effect is further improved by repeating the recalculation of the SOC conversion index SOCc during traveling on the guidance route, and the braking / driving force characteristics of the vehicle are determined by determining the SOC conversion index SOCc so that the SOC falls within a predetermined range. Has improved.
[0004]
[Problems to be solved by the invention]
However, the conventional hybrid vehicle control device described above does not take into account changes in the vehicle weight during traveling on a guided route, so hybrid vehicles such as home delivery trucks, buses, hires, tow trucks, etc., whose load changes greatly during route traveling. On the other hand, there is a problem that it is not possible to sufficiently achieve reduction in fuel consumption and improvement in braking / driving force characteristics at the time of running through the guidance route.
[0005]
An object of the present invention is to reduce the fuel consumption of a hybrid vehicle whose vehicle weight changes during traveling on a guidance route and to improve the braking / driving force characteristics.
[0006]
(1) The invention of claim 1 is applied to a control device for a hybrid vehicle that uses one or both of an engine and a motor as a braking / driving force source and transfers electric power between the motor and the battery.
  A navigation device for instructing a guidance route of the vehicle and providing road information on the guidance route; a vehicle weight setting means for setting the weight of the vehicle on the guidance route; an SOC detection means for detecting the SOC of the battery; , Dividing the guide route into a plurality of sections, and detecting the vehicle speed, SOC calculating means for calculating the SOC in each section of the guide route based on the road information, the vehicle weight, and the SOC detection value of each section A vehicle speed detecting means, an accelerator opening detecting means for detecting an accelerator pedal depression amount (hereinafter referred to as an accelerator opening), and a braking / driving force command value is set based on the vehicle speed detection value and the accelerator opening detection value. Based on the braking / driving force command value setting means, the vehicle speed detection value, the braking / driving force command value, and the SOC calculation value, the operating points of the engine and the motor are determined. And a driving point determining means constant for,The SOC calculation means sets a lower limit value of the SOC calculation value in each section of the guidance route, increases the SOC lower limit value as the vehicle weight increases, and calculates the SOC calculation value in each section of the guidance route. By setting the upper limit value of the vehicle and decreasing the SOC upper limit value as the vehicle weight increases,Achieving the above objectives.
(2) The hybrid vehicle control device according to claim 2 is configured to calculate an SOC that runs through the guidance route with a minimum fuel consumption by the SOC calculation means.
(3) The hybrid vehicle control device according to claim 3 is:The vehicle weight setting means allows the vehicle occupant to manually input and set the vehicle weight.It is what I did.
(4) The hybrid vehicle control device according to claim 4 is:The vehicle weight setting means automatically sets the weight of the vehicle in accordance with the planned passenger entry / exit and / or loading / unloading of luggage.It is what I did.
[0007]
【The invention's effect】
(1) According to the invention of claim 1, the weight of the vehicle on the guide route is set, and the SOC of each section of the guide route is calculated based on the road information, vehicle weight, and SOC detection value of each section of the guide route. Then, the braking / driving force command value is set based on the vehicle speed detection value and the accelerator opening detection value, and the engine and motor operating points are determined based on the vehicle speed detection value, braking / driving force command value, and SOC calculation value.. At this time, the lower limit value of the SOC calculation value in each section of the guidance route is set, the SOC lower limit value is increased as the vehicle weight increases, and the upper limit value of the SOC calculation value in each section of the guidance route is set. The higher the value, the lower the SOC upper limit value.I did it.
  As a result, the SOC after traveling through the guide route can be kept within the target value or a predetermined range even for a hybrid vehicle having a large change in vehicle weight due to passengers getting on and off or loading and unloading luggage on the guide route.In a hybrid vehicle, it is desirable to always ensure braking / driving force by a motor in order to maintain good braking / driving force characteristics. Therefore, for example, before the uphill, it is necessary to increase the SOC of the battery in advance in consideration of the power consumption of the battery driven by the motor during the uphill. The battery power consumption due to the motor driving during climbing increases as the vehicle weight increases. Therefore, by increasing the SOC lower limit value as the vehicle weight increases, the driving force of the motor can be secured even when the vehicle weight increases. it can. In addition, for example, before the downhill, it is necessary to reduce the SOC of the battery in advance so that regenerative power can be accepted in consideration of charging of the battery due to motor regenerative braking during the downhill. The amount of battery charge due to motor regenerative braking during downhill increases as the vehicle weight increases. Therefore, the braking force of the motor is ensured even if the vehicle weight increases by reducing the SOC upper limit value as the vehicle weight increases. be able to. Therefore,Battery SOC can be planned and managed in consideration of changes in vehicle weight, and even after a hybrid vehicle with a large change in vehicle weight, the SOC after running on the guidance route can be reliably kept within the target value or within a specified range. As a result, the braking / driving force of the motor can be secured and the braking / driving characteristics of the vehicle can be improved.
(2) According to the invention of claim 2, since the SOC that runs through the guidance route with the lowest fuel consumption is calculated, in addition to the effect of claim 1, there may be a change in the vehicle weight in the middle of the guidance route. It is possible to plan and manage a battery SOC that can achieve fuel consumption, and to reduce fuel consumption.
(3) According to the invention of claim 3,Since the vehicle occupant manually inputs and sets the vehicle weight, the vehicle weight can be arbitrarily input according to the passenger entry / exit and loading / unloading plans on the guidance route, and the number of passengers and loading / unloading loads The input vehicle weight can be changed according to the vehicle. As a result, the battery SOC can be planned and managed based on the exact vehicle weight, and the fuel consumption in the guide route can be reduced and the braking / driving characteristics can be improved.
(4) According to the invention of claim 4,The weight of the vehicle is automatically set according to the planned passenger entry / exit and / or loading / unloading of the passenger. Therefore, the time required for inputting the vehicle weight is saved, and the battery SOC is adjusted based on the exact vehicle weight. Planning and management can be executed, and fuel consumption in the guide route can be reduced and braking / driving characteristics can be improved.
[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. Further, 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. A road map database is provided, the optimum route to the destination is searched, and the optimum route to the vehicle current location and the destination is displayed on the display 41 to guide the occupant.
[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, regulation information such as speed limits, and area information such as city roads and mountain roads. 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]
The weight change predicted value input device 40 is linked to the navigation device 33 and can input the predicted weight of the vehicle at an arbitrary point on the guidance route to the destination searched by the navigation device 33. For example, the driver inputs 1700 kg at the departure point, 1800 kg at the transit point A, and 1850 kg at the transit point B along the guidance route from the departure point to the destination displayed on the display 41. When the vehicle is a delivery truck, the package collection plan information is obtained from the delivery center, and the estimated vehicle weight is input based on the package collection plan weight. If the vehicle is a hire or taxi, it will search for the guidance route based on the passenger boarding place and drop-off location obtained from the information center, and based on the number of passengers and baggage information obtained from the information center, Enter the predicted weight. Further, when the vehicle is a bus or a luggage truck, the navigation device searches for a guidance route, and inputs a predicted weight of the vehicle based on loading and unloading of the luggage on the guidance route and passengers getting on and off.
[0022]
If there is a discrepancy between the predicted weight and the actual weight during traveling on the guidance route, the driver grasps the difference between them by measuring the weight of the baggage, and the correct predicted weight is input by the weight change predicted value input device 40. Enter again.
[0023]
<< Calculation method of SOC conversion efficiency index SOCc >>
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 suppressing the fuel consumption in the guide path to the minimum.
[0024]
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, the higher the 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.
[0025]
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 course of the route to the destination, An SOC conversion efficiency index SOCc that determines the operating points of the engine 2 and the motors 1 and 4 in the course of the route is obtained by calculation.
[0026]
When this SOC conversion efficiency index SOCc is large, the amount of increase in charging power Δbat per unit fuel increase amount Δfuel for battery charging increases, that is, the fuel utilization efficiency at the time of battery charging increases. The operating point of the engine 2 and the motors 1 and 4 is determined so as to charge only, and conversely, when the SOC conversion efficiency index SOCc is small, the engine 2 is charged even when the fuel utilization efficiency during battery charging is low. And determine the operating point of motors 1 and 4.
[0027]
The calculation method of SOC conversion efficiency parameter | index SOCc is demonstrated with FIG.
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 respectively 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. Shows the minimum fuel consumption, charge / discharge amount, and SOC change.
[0028]
As described above, the SOC conversion efficiency index SOCc is an index representing the fuel utilization efficiency during battery charging. Therefore, as 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.
[0029]
Some value is set in the SOC conversion efficiency index SOCc, and the 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, a 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.
[0030]
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 at (p_SOC (n)) is calculated, the SOC conversion efficiency index SOCc is
[Expression 1]
SOCc = SOCc + α (α> 0)
Increase to 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)
Reduce and recalculate.
[0031]
When the above calculation is repeated until the predicted SOC (p_SOC (n)) at the destination substantially matches the target SOC (t_SOC) at the destination, that is, until 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. Hereinafter, the final SOC conversion efficiency index SOCc_j is referred to as a determined value of the SOC conversion efficiency index. 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.
[0032]
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, if the current SOC (d_SOC) is small when traffic is heavy, 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 corrected to be smaller as the current SOC (d_SOC) is smaller based on the SOCc at that time.
[0033]
<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.
[0034]
When the calculation for determining the SOC conversion efficiency index SOCc is performed, the SOCc being temporarily set, 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 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.
[0035]
In any operation point determination, the operation point is determined so that charging is performed only when the SOC conversion efficiency index SOCc_j or SOCc is larger and the fuel use efficiency during battery charging is higher.
[0036]
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 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.
[0037]
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].
[0038]
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.
[0039]
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.
[0040]
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.
[0041]
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.
[0042]
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.
[0043]
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.
[0044]
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.
[0045]
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.
[0046]
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. Then, 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 is converged. SOCc_j at the time is determined as the final SOC conversion efficiency index SOCc.
[0047]
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.
[0048]
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.
[0049]
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 of the divided section way (i) (i = 1 to n) is also detected. In the following step 2, it is confirmed whether there is a new input or change of the destination, a deviation of the guidance route, a change in the vehicle weight input value, or a change in the traffic condition. If not, go to step 11. In addition, the change of the traffic situation is obtained by a road-to-vehicle communication device such as VICS.
[0050]
When there is any new input or change of the destination, deviation of the guidance route, change of the vehicle weight input value, 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 are a method of classifying the change point of the vehicle weight input value as a classification point, a method of classifying the distance to the destination by dividing it into n equal parts, and the like. 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.
[0051]
In step 5, road environment such as average gradient, intersection position, radius of curvature, altitude 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).
[0052]
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 position 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, the vehicle speed p_vsp (i) that predicts the vehicle speed p_vsp (i) at a deceleration of 0.1G and returns to the cruising speed at an acceleration of 0.1G after a 3-second stop at the 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. Further, 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) for each divided section way (i) includes the driving force for the running resistance (air resistance + rolling resistance) according 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. Here, the rolling resistance component and the acceleration / deceleration component (speed difference, potential energy variation component) are calculated based on the predicted vehicle weight value of the corresponding section input from the weight variation predicted value input device 40.
[0053]
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 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 the internal division value of the previous vehicle speed m_vsp (i) may be taken. 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.
[0054]
In step 8, the current SOC (d_SOC) is detected, and in the subsequent 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 determined value SOCc_J, predicted vehicle speed p_vsp (i), and predicted braking / driving force command value p_tTd (i), the SOC (p_SOC (i) of each divided section way (i) is calculated. ). First, based on the SOC conversion efficiency index determination value SOCc_j, the predicted vehicle speed p_vsp (i), and the predicted braking / driving force command value p_tTd (i), as described above, the engine 2 and the motor 1, 1 in each divided section way (i) When the temporary operating point of 4 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 estimated 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 calculated. Can be predicted.
[0055]
In step 11, the vehicle speed sensor 23 detects the vehicle speed d_vsp, and in step 12, the accelerator sensor 22 detects the accelerator opening d_acc. 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.
[0056]
In step 14, at the end point 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;
[0057]
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.
[0058]
Further, there is a method in which the power error exerted on the vehicle is highly correlated with the fuel consumption and charge / discharge power of interest 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 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 guide route has taken before, the vehicle speed pattern m_vsp (i) of the route section when the guide route has passed previously may be used as the predicted vehicle speed p_vsp (i), or the predicted vehicle speed p_vsp (i ) And the previous vehicle speed m_vsp (i) may be taken. 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.
[0059]
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 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
[0060]
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, if 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, priority is given to the protection of the battery 15, and the detected SOC is substituted for 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.
[0061]
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.
[0062]
In calculating the SOC conversion efficiency index SOCc, the predicted SOC (p_SOC (i)) of all the divided sections way (i) is calculated. Therefore, 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.
[0063]
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 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 conversion efficiency index SOCc is converged to the converged value SOCc_j until it substantially agrees 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.
[0064]
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 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.
[0065]
<< 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.
[0066]
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.
[0067]
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, whether or not there is a new input or change of the destination, deviation of the guidance route, change of the weight input value, or change of the traffic congestion state is confirmed, and if any, the process proceeds to step 3 If there is nothing, go to step 11.
[0068]
When there is any new input or change of the destination, deviation of the guidance route, change of the weight input value, or change of the traffic jam condition, 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).
[0069]
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 certain 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%.
[0070]
Here, since the battery power required to maintain the driving force varies depending on the vehicle weight even on the same uphill, the lower limit value is set to 50% when the vehicle weight is 1600 kg, for example, and 53% when the vehicle weight is 1700 kg. In other words, the SOC lower limit value is increased as the vehicle weight increases. FIG. 15 shows a method for setting the SOC upper and lower limit values according to the vehicle weight. FIG. 15 shows that in the route from the depot at the departure place to the depot at the destination, the road type and the gradient pattern of the section A and the section B are the same, and the predicted vehicle weight when traveling in the section B is the same as when traveling in the section A. The SOC upper and lower limit values and the target SOC (t_SOC) when the vehicle weight is heavier than the predicted vehicle weight are shown. In FIG. 15, when the predicted vehicle weight at the time of traveling in the section B is heavier than the predicted vehicle weight at the time of traveling in the section A, the SOC lower limit value SOCL2 of the section B is made larger than the SOC lower limit value SOCL1 of the section A. In addition, the upper limit value of the battery is set so that the battery charging by the regenerative braking force is effectively utilized before the downhill. At this time, if the vehicle is on the same downhill, the change in potential energy increases as the vehicle weight increases, and accordingly, the expected regenerative power increases. Therefore, the SOC upper limit value decreases as the vehicle weight increases. In FIG. 15, when the predicted vehicle weight at the time of traveling in the section B is heavier than the predicted vehicle weight at the time of traveling in the section A, the SOC upper limit value SOCH2 of the section B is made smaller than the SOC upper limit value SOCH1 of the section A.
[0071]
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.
[0072]
In this way, the lower limit value of the SOC calculation value in each section of the guidance route is set, and the SOC lower limit value is increased as the vehicle weight increases. In addition, an upper limit value of the SOC calculation value in each section of the guidance route is set, and the SOC upper limit value is decreased as the vehicle weight increases. In a hybrid vehicle, it is desirable to always ensure braking / driving force by a motor in order to maintain good braking / driving force characteristics. Therefore, for example, before the uphill, it is necessary to increase the SOC of the battery in advance in consideration of the power consumption of the battery driven by the motor during the uphill. The battery power consumption due to the motor driving during climbing increases as the vehicle weight increases. Therefore, by increasing the SOC lower limit value as the vehicle weight increases, the driving force of the motor can be secured even when the vehicle weight increases. it can. In addition, for example, before the downhill, it is necessary to reduce the SOC of the battery in advance so that regenerative power can be accepted in consideration of charging of the battery due to motor regenerative braking during the downhill. The amount of battery charge due to motor regenerative braking during downhill increases as the vehicle weight increases. Therefore, the braking force of the motor is ensured even if the vehicle weight increases by reducing the SOC upper limit value as the vehicle weight increases. be able to.
[0073]
In step 7, as described above, based on the road environment of each divided section way (j), the vehicle speed p_vsp (i) and the braking / driving force command value p_tTd () in each divided section way (i) between the current location and the destination. i) Predict. 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. In addition, 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. Further, 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, the braking / driving force command value p_tTd (i) of each divided section way (i) includes the driving force for the running resistance (air resistance + rolling resistance) according to the vehicle speed p_vsp (i), 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. Here, the rolling resistance and acceleration / deceleration (speed difference, potential energy change) are calculated based on the predicted vehicle weight of the corresponding section input from the vehicle weight change predicted value input device 40.
[0074]
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), as described above, the engine 2 and the motors 1 and 4 in each divided section way (i). 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 estimated 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 calculated. Can be predicted.
[0075]
In step 22, it is confirmed whether or not the predicted SOC (p_SOC (i)) of each 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, the SOC conversion efficiency index SOCc is corrected 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 (1). 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 Equation 2 until the upper limit value is not exceeded. 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.
[0076]
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 up to the destination, the target The actual SOC on 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. 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).
[0077]
When there is no new input or change of the destination, departure of the guidance route, change of the vehicle weight input value, or change of the traffic jam condition, the vehicle speed d_vsp is detected by the vehicle speed sensor 23 in step 11, and the accelerator is subsequently executed in step 12. The accelerator opening d_acc is detected by the 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.
[0078]
In step 14, at the end point of each divided section way (j), the 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 command of each divided section are determined. 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 determination reference value at the end point of each divided section way (i). Return to 9, and recalculate the SOC conversion efficiency index SOCc. 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. For example, ERR_3 shown in Equation 5 can be used as the deviation index.
[0079]
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 / lower limit value 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, and the SOC conversion efficiency index SOCc is recalculated. 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.
[0080]
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.
[0081]
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)) of each section way (i) is closest to the SOC upper / lower limit value, or the intersection PA of the change curve of the predicted SOC (p_SOC (i)) and the SOC upper / lower limit value Remember. When the current SOC (d_SOC) approaches the SOC upper or lower limit value or reaches the above point PA when the engine / motor operating point is determined based on the SOC conversion efficiency index SOCc and the vehicle is traveling, the subsequent SOC conversion The efficiency index SOCc is recalculated, 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.
[0082]
<< 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.
[0083]
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.
[0084]
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 there is a new input or change of the destination, a deviation of the guidance route, a change in the vehicle weight input value, or a change in the traffic condition. If not, go to step 11. 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, radius of curvature, 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.
[0085]
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, driving patterns are assumed for each road environment and vehicle weight, and these driving patterns are stored in advance in the memory as SOC change amount data (MAP2DSOC) per unit distance when driving with the SOC conversion efficiency index SOCc. Then, from this data (MAP2DSOC), the SOC change efficiency p_dSOC (j) corresponding to the SOC conversion efficiency index SOCc and the road environment and the vehicle weight for each section way (j) is subjected to a table calculation, and the current SOC (d_SOC) Is the initial value, and the SOC change amount p_dSOC (j) of each section way (j) is integrated, so that the predicted SOC (p_SOC (j)) of each section way (j) and the predicted SOC at the destination (p_SOC (m)) ) 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-equivalent efficiency index when both are almost the same is obtained as the final index SOCc. To do.
[0086]
In step 11, the vehicle speed sensor 23 detects the vehicle speed d_vsp, and in step 12, the accelerator sensor 22 detects the accelerator opening d_acc. 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.
[0087]
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.
[0088]
In step 15, it is determined whether 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. Note that the reference value ERR_3 can be used in Equation 3 as the determination reference value.
As an index of deviation shown, for example, there is the one shown in the following equation.
[0089]
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, if 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, priority is given to the protection of the battery 15, and the detected SOC is substituted for 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.
[0090]
The road environment information, vehicle weight 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. You may make it do. Thereby, it is possible to predict the SOC change amount for each more accurate section way (j).
[0091]
As described above, according to the third embodiment, assuming a travel pattern for each road environment and the vehicle weight, the SOC change per unit travel distance when the travel pattern is traveled with various SOC conversion efficiency indexes. Quantity data is previously stored in a memory. Then, from the SOC change amount data per unit travel distance, the SOC change efficiency index SOCc and the SOC change amount p_dSOC (j) corresponding to the road environment and the vehicle weight for each section way (j) are calculated and calculated. By integrating the SOC change amount p_dSOC (j) of each section way (j) using the current SOC (d_SOC) as an initial value, the predicted SOC (p_SOC (j)) of each section way (j) and the prediction at the destination are integrated. Obtain SOC (p_SOC (m)). This calculation is performed 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. The actual SOC change amount d_dSOC (k) and the calculated SOC change amount p_dSOC (k) in each section way (k) when the engine / motor operating point is determined based on the SOC conversion efficiency index SOCc. ), And if the deviation is large, the SOC conversion efficiency index (SOC) is corrected. Further, in each section way (j), the current SOC (d_SOC) and the predicted SOC (p_SOC (i)) are compared, 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.
[0092]
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.
[0093]
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” of 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.
[0094]
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.
[0095]
Furthermore, in the above-described embodiment, the continuously variable transmission has been described as an example. However, the transmission is not limited to a continuously variable transmission, and may be a stepped transmission. Further, the arrangement of the transmission is not limited to the above-described embodiment.
[0096]
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.
[0097]
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 substantially matching (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.
[0098]
In the above-described embodiment, an example in which the predicted value of the vehicle weight change is input on the guidance route display screen displayed on the display 41 of the navigation device 33 has been described. However, the input method of the predicted vehicle weight change value is described above. It is not limited to the input method of the embodiment. For example, in a parcel delivery truck, the loading / unloading information is managed at the delivery management center, and the loading / unloading point and loading weight are transmitted from the delivery management center, and the vehicle weight change point and the vehicle weight change amount on the guidance route are automatically transmitted. You may make it set to. In addition, a delivery route may be planned in advance according to management data from the delivery management center. In such a case, the delivery route may be searched for on the basis of the route and destination of the delivery truck on the delivery management center side, and the guidance route and waypoint of the search result may be transmitted to the delivery truck. Further, the home delivery management center may perform the calculation up to the SOC conversion efficiency index SOCc in consideration of the change in the vehicle weight. In that case, it is sufficient to receive the SOC conversion efficiency index SOCc on the delivery truck side and operate the engine and the motor according to the value, and it is necessary to search for the guidance route and to calculate the SOC conversion index SOCc with an on-board microcomputer. Therefore, it is possible to save processing time in the in-vehicle device and reduce the cost of the in-vehicle device. Of course, such an embodiment is not limited to a delivery truck, but can also be applied to a hire, a taxi, a bus, and the like that are operated according to operation information from an operation management center.
[0099]
In this way, the weight of the vehicle on the guidance route is set, and the SOC of each segment of the guidance route is calculated based on the road information, vehicle weight, and SOC detection value of each segment of the guidance route. Then, the braking / driving force command value is set based on the vehicle speed detection value and the accelerator opening detection value, and the operating points of the engine and the motor are determined based on the vehicle speed detection value, the braking / driving force command value, and the SOC calculation value. did. As a result, the SOC after traveling through the guide route can be kept within the target value or a predetermined range even for a hybrid vehicle having a large change in vehicle weight due to passengers getting on and off or loading and unloading luggage on the guide route. For the calculation method of the battery SOC, for example, in order to always ensure the braking / driving force by the motor, an SOC range (for example, 40 to 70%) in which power can be transferred between the battery and the motor over the entire section of the induction path is available. There is a way to maintain. In such a case, it becomes possible to plan and manage the battery SOC in consideration of the change in the vehicle weight, and even for a hybrid vehicle having a large change in the vehicle weight, the SOC after running the guide route is within the target value or a predetermined range. As a result, the braking / driving force of the motor can be secured and the braking / driving characteristics of the vehicle can be improved. In addition, since the SOC that runs through the guidance route with the lowest fuel consumption is calculated, it is possible to plan and manage the battery SOC that can achieve good fuel consumption even if there is a change in the vehicle weight along the guidance route. Can be reduced.
[0100]
The correspondence between the constituent elements of the claims and the constituent elements of the embodiment is as follows. That is, the weight change predicted value input device 40 serves as vehicle weight setting means, the battery SOC sensor 25 serves as SOC detection means, the vehicle controller 16 serves as SOC calculation means, braking / driving force command value setting means, and operating point determination means as vehicle speed sensors. Reference numeral 23 denotes vehicle speed detection means, and the accelerator sensor 22 constitutes accelerator opening detection means.
[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 an operating point of the engine.
FIG. 5 is a graph 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 and 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 the vehicle control program according to the third embodiment, following FIG. 13;
FIG. 15 is a diagram for explaining a method of setting an SOC upper / lower limit value according to a vehicle weight.
[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
40 Weight change prediction value input device
41 display

Claims (4)

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,
A navigation device for instructing a vehicle guidance route and providing road information on the guidance route;
Vehicle weight setting means for setting the weight of the vehicle in the guidance route;
SOC detection means for detecting the SOC of the battery;
SOC calculating means for dividing the guide route into a plurality of sections and calculating the SOC in each section of the guide route based on the road information, the vehicle weight and the SOC detection value of each section;
Vehicle speed detection means for detecting the vehicle speed;
An accelerator opening detecting means for detecting an accelerator pedal depression amount (hereinafter referred to as an accelerator opening);
Braking / driving force command value setting means for setting a braking / driving force command value based on the vehicle speed detection value and the accelerator opening detection value;
Operating point determination means for determining operating points of the engine and the motor based on the vehicle speed detection value, the braking / driving force command value, and the SOC calculation value ;
The SOC calculation means sets a lower limit value of the SOC calculation value in each section of the guidance route, increases the SOC lower limit value as the vehicle weight increases, and calculates the SOC calculation value in each section of the guidance route. control apparatus for a hybrid vehicle that sets an upper limit value, and wherein to Rukoto reduce the SOC upper limit value as the vehicle weight is large. In the hybrid vehicle control device according to claim 1,
The control device for a hybrid vehicle, wherein the SOC calculation means calculates an SOC that runs through the guidance route with minimum fuel consumption. In the hybrid vehicle control device according to claim 1 or 2,
The hybrid vehicle control device is characterized in that the vehicle weight setting means is set by a vehicle occupant manually inputting the vehicle weight . In the hybrid vehicle control device according to claim 1 or 2 ,
The hybrid vehicle control apparatus, wherein the vehicle weight setting means automatically sets the vehicle weight in accordance with a passenger's boarding / exiting and / or loading / unloading of a cargo planned in advance .

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