Control device for a hybrid vehicle
Patent Information
- Application Number
- DE102016122254
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2015-11-19
- Filing Date
- 2016-11-18
- Publication Date
- 2025-03-20
- Estimated Expiration
- 2036-11-18
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
BACKGROUND OF THE INVENTIONField of the invention
[0001] The present invention relates to a control device for a hybrid vehicle that controls a hybrid vehicle including both an internal combustion engine and a motor as a drive source of the hybrid vehicle. Description of the related art
[0002] A hybrid vehicle (hereinafter referred to simply as a "vehicle") that includes both an internal combustion engine (hereinafter referred to simply as a "power engine") and a motor as the vehicle's power sources is known. The vehicle includes a storage battery, or accumulator, which supplies electric power to the motor while being charged with the output of the internal combustion engine.
[0003] In addition, when rotation of an axle is transmitted to the motor, a generator generates electric power (namely, the motor generates electricity), and the battery is also charged by the electric power. That is, the vehicle's kinetic energy is converted into electrical energy, and the electrical energy is accumulated by the battery. This energy conversion may be referred to as "regeneration." When regeneration is performed, the braking force of the vehicle generated by the motor (namely, a torque that decelerates the vehicle speed) may be referred to as "regenerative braking force," and the braking of the vehicle using the regenerative braking force may be referred to as "regenerative braking."Electric power accumulated in the battery through regenerative braking may be referred to as "regenerative electric power." When energy is accumulated in the battery by performing regenerative braking at the time of vehicle deceleration, fuel consumption (specific fuel consumption) of the vehicle can be improved.
[0004] In contrast, a remaining capacity SOC (state of charge, hereinafter simply referred to as "SOC") of the battery changes during vehicle driving. If the remaining capacity SOC is repeatedly increased and decreased when the remaining capacity SOC is in one of a state where the remaining capacity SOC is high and a state where the remaining capacity SOC is low, deterioration of the battery is promoted. Therefore, during vehicle driving, a control device for a vehicle sets a target remaining capacity to an appropriate value between a residual capacity upper limit and a residual capacity lower limit, and controls the internal combustion engine and the motor such that the remaining capacity SOC approaches the target remaining capacity.
[0005] Incidentally, when a vehicle is traveling on a slope, a driver generally takes his foot off the accelerator pedal and, in some cases, also presses the brake pedal (depending on the circumstances). At this time, a control device for the vehicle suppresses an increase in vehicle speed by using regenerative braking force, thereby increasing the residual capacity (SOC).
[0006] As the remaining capacity SOC increases (i.e., as the amount of electric power charged into a storage battery increases), the distance the vehicle can travel with only the engine output while stopping the engine operation becomes longer. Therefore, if the remaining capacity SOC can be increased as much as possible within a range smaller than the remaining capacity limit when the vehicle is traveling on a slope, the vehicle's fuel consumption can be further increased.
[0007] However, since the remaining capacity SOC soon reaches the remaining capacity limit when a downhill slope is long, it becomes impossible to further increase the remaining capacity SOC. Therefore, the larger the difference between the remaining capacity SOC and the remaining capacity limit at the starting point of the downhill slope, the greater the fuel consumption improvement effect obtained by driving downhill.
[0008] Then, when a slope portion having a predetermined elevation difference exists on a planned travel route, one of conventional control devices for a hybrid vehicle (which may be referred to as a "conventional device" hereinafter) gives priority to travel in which operation of an internal combustion engine is stopped and only a motor is operated, over travel in which both an internal combustion engine and a motor are operated, so that a remaining capacity SOC approaches a remaining capacity lower limit as much as possible before a vehicle enters the slope portion (see Patent Publication JP 2005 - 160 269 A).Hereinafter, driving in which operation of an internal combustion engine is stopped and only a motor is operated may be referred to as “EV driving,” and driving in which both an internal combustion engine and a motor are operated may be referred to as “HV driving.”
[0009] According to this conventional device, since the remaining capacity SOC is made lower than that at a normal time during a period when the vehicle travels a section before the vehicle arrives at a starting point of the downhill section (which may be referred to as a "pre-use section" hereinafter), a usage frequency of the internal combustion engine during that period decreases. Furthermore, since the difference between the remaining capacity SOC and the remaining capacity upper limit becomes larger at the starting point of the downhill section, larger electric power can be accumulated during traveling on the downhill section. Consequently, the usage frequency of the internal combustion engine also decreases thereafter. As a result, the fuel consumption of the hybrid vehicle can be improved.
[0010] In contrast, a technology called "extended regeneration control" is also known in the art. When a vehicle is predicted to decelerate based on information about a driver's operating tendency (e.g., a deceleration action, etc.) and a vehicle's location, etc., a control device executing extended regeneration control sets a point at which the deceleration of the value is predicted to end as a target deceleration end point.Furthermore, the present control device increases a regenerated electric power amount by setting an appropriate deceleration start point and increasing a regenerative braking force from the deceleration start point so that the regenerated electric power amount becomes larger during a deceleration run to this target deceleration end point (in other words, so that a consumption amount of energy by braking using a friction braking force device resulting from execution of rapid deceleration becomes smaller) (see Patent Publication JP 2014 - 110 677 A).
[0011] Thus, since advanced regeneration control can further increase the residual capacity (SOC), the distance for which EV driving is possible becomes longer. Consequently, the fuel consumption of a hybrid vehicle can be further improved by applying advanced regeneration control.
[0012] US 2015 / 0 019 057 A1 describes a vehicle with a regenerative generator. The vehicle includes an energy storage unit, a regenerative generator, and an electronic control unit. The regenerative generator is connected to the energy storage unit and configured to perform regenerative power generation. The electronic control unit is configured to perform regeneration amount increase control, in which vehicle stopping and deceleration positions are predicted or set by inputting a driver's operation based on route information, regenerative power generation by the regenerative generator is controlled, and an amount of regeneration energy loaded into the energy storage unit is increased.The electronic control unit is configured to limit the regeneration amount increase control when a predetermined vehicle speed adjustment mode is executed by comparing when the predetermined vehicle speed adjustment mode is not selected, wherein the vehicle travels with automatic adjustment of the vehicle speed in the predetermined vehicle speed adjustment mode selected by an intentional input from the driver. SUMMARY OF THE INVENTION
[0013] In addition, when a vehicle travels through a congested section, the vehicle travels at low speed or repeatedly travels at low speed and stops. Consequently, when a vehicle travels through a congested section, the amount of regenerated electric power is small, as the frequency of EV travel increases and the frequency of deceleration from low speed travel increases. As a result, the residual capacity (SOC) decreases.
[0014] Consequently, since the remaining capacity SOC reaches the lower limit when the congestion section is long, EV driving becomes impossible, resulting in the need to switch to HV driving. Furthermore, "forced charging" can be performed, in which an internal combustion engine is operated to increase the remaining capacity SOC and a battery is forcibly charged with the output of the internal combustion engine. Thus, as the operating opportunity of an internal combustion engine increases, fuel consumption of a vehicle deteriorates. Consequently, the difference between the remaining capacity SOC and the lower limit at the starting point of a congestion section becomes smaller.
[0015] From such a viewpoint, control has been considered in which the remaining capacity SOC at a starting point of a congestion section is increased by setting a target remaining capacity SOC higher than that at a normal time until a vehicle arrives at the congestion section when the congestion section is expected to exist on a planned travel route. Such control may be referred to as "congestion control." Furthermore, the congestion control and the aforementioned slope control may be collectively referred to as "look-ahead assist control."
[0016] However, when the downhill control is used jointly as the look-ahead assist control and the extended regeneration control, the extended regeneration control may be executed in a period when a vehicle travels, for example, the above-mentioned pre-use section and a downhill section. In this case, even though the target remaining capacity is set to a value lower than that at a normal time in the pre-use section, there may be a case where the remaining capacity SOC at a starting point of the downhill section has not yet been sufficiently reduced by the extended regeneration control. Furthermore, there may be a case where the remaining capacity SOC increases more than expected by the extended regeneration control in a downhill section.As a result, a situation may occur in which the remaining capacity SOC reaches the remaining capacity upper limit and consequently cannot be increased further, whereby an electric power that could have been accumulated in a storage battery during driving on a slope section cannot be accumulated.
[0017] Furthermore, when congestion control is used jointly as the look-ahead assist control and the extended regeneration control, for example, a case may occur where the extended regeneration control is executed in a state where the remaining capacity SOC is high. Because the target remaining capacity is set to a large value by the congestion control, the remaining capacity SOC continues to increase and reaches the remaining capacity upper limit. Also in this case, since the remaining capacity SOC cannot be increased any further, electric power that could have been accumulated in the battery cannot be accumulated.
[0018] As is apparent from the above description, when the look-ahead assist control and the extended regeneration control are used together, there is a possibility that electric power that could have been collected cannot be collected.
[0019] Then, one of objects of the present invention is to provide a control device for a hybrid vehicle that can improve fuel consumption by accumulating more regenerative electric power in a “control device for a hybrid vehicle” that includes a control part configured to be capable of executing the look-ahead assist control (at least one of the slope control and the congestion control) and the extended regeneration control.
[0020] This object is achieved by a control device according to claim 1. An advantageous further development is specified in the dependent claim.
[0021] A control device for a hybrid vehicle according to a configuration for achieving the above-mentioned object is applied to a hybrid vehicle (10) comprising an internal combustion engine (23) as a drive source of a vehicle and motors (21, 22) as drive sources, and an accumulator (31) that supplies electric power to the motors, is configured to be capable of performing regenerative braking using the motors and charging the accumulator with electric power generated by the regenerative braking, and is configured to be capable of charging the accumulator with electric power generated using output power in the internal combustion engine.
[0022] In addition, the device according to the embodiment comprises a control part (40) configured to control the internal combustion engine and the motors such that a demand driving force required for the vehicle is satisfied and that the remaining capacity of the storage battery approaches a target remaining capacity (SOC*) set to a standard remaining capacity (Sn).
[0023] Furthermore, the control part includes: an information acquisition device configured to acquire information about a planned route of the vehicle and a location of the vehicle (40, 61, 63, step S101, S111), an assistance control device (40) configured to perform, as a look-ahead assistance control, at least one control from a slope control (routine according to Fig. 10 or Fig. 14) and a traffic jam control (routine according to Fig. 11 or Fig. 15) and an advanced regeneration control device configured to perform an advanced regeneration control (routine according to Fig. 12, Fig. 40).
[0024] Slope control is control in which the target remaining capacity is changed to a low-side remaining capacity (Sd) smaller than the standard remaining capacity (Sn) while the vehicle is traveling on a section including at least one pre-use section within a first section, when it is judged, based on information about the planned travel route, that "a planned travel route of the vehicle includes a slope section that satisfies a predetermined slope section condition." The pre-use section is a section from "a start point of the slope control" to "a start point of the slope section." The first section is a section from "the start point of the slope control" to "an end point of the slope section." The start point of the slope control is "a point a predetermined first distance ahead of the start point of the slope section."
[0025] Congestion control is a control in which the target remaining capacity is changed to a high-side remaining capacity (Sh) greater than the standard remaining capacity (Sn) while the vehicle is traveling in a second leg when, based on information about the planned travel route, it is judged that the vehicle's planned travel route includes a congestion leg that meets a predetermined congestion leg condition. The second leg is a leg from "a congestion control start point" to "a congestion leg start point." The congestion control start point is a point a predetermined second distance ahead of the congestion leg start point.
[0026] The extended regeneration control is a control in which a location at which the deceleration of the vehicle is predicted to end is set as a target deceleration end location, and the vehicle is decelerated by the regenerative braking such that an amount of electric power charged into the accumulator by the regenerative braking when the vehicle decelerates with the target deceleration end location set becomes larger compared to that when the vehicle decelerates with the target deceleration end location not set, when the vehicle is predicted to decelerate based on information about a location of the vehicle.
[0027] As described above, when the congestion control as the look-ahead support control and the extended regeneration control are used together, there may occur a case where the extended regeneration control is executed in a period when a vehicle travels the pre-use section and the downhill section and, as a result, the remaining capacity SOC reaches the remaining capacity upper limit.
[0028] Furthermore, when the congestion control as the look-ahead assist control and the extended regeneration control are used together, a case may occur in which the extended regeneration control is executed when the target remaining capacity is set to a large value by the congestion control, and as a result, the remaining capacity SOC further reaches the remaining capacity upper limit.
[0029] Then, the control part comprises a target residual capacity correction device (40) which is configured: correct the target remaining capacity to a value which is a first adjustment quantity (ΔS1, ΔS1a) which is smaller than the low-side remaining capacity (step S104 to step S106 according to Fig. 10 and steps S142 to S144 and step S105 according to Fig. 14), in a first case where it is assumed that an electric power amount charged into the accumulator by the extended regeneration control when the assistance control device is configured to execute the slope control as the look-ahead assistance control and the vehicle travels the first section is greater than a first threshold electric power amount (judgment as “Yes” in step S104 according to Fig. 10 and judgment as “Yes” in step S142 according to Fig. 14), and correct the target remaining capacity to a value which is a second adjustment amount (ΔS2, ΔS2a) which is smaller than the high-side remaining capacity (step S114 to step S116 according to Fig. 11 and step S152 to step S154 and step S115 according to Fig. 15), in a second case where it is assumed that an electric power amount charged into the accumulator by the extended regeneration control when the assistance control device is configured to execute the congestion control as the look-ahead assistance control and the vehicle travels the second section is greater than a second threshold electric power amount (judgment as “Yes” in step S114 according to Fig. 11 and judgment as “Yes” in step S152 according to Fig. 15).
[0030] According to the aforementioned target remaining capacity correction means, the target remaining capacity is corrected to a "value that is a first adjustment amount smaller than the low-side remaining capacity" in the first case when the assist control means is configured to execute the downhill control as the look-ahead assist control. Therefore, even in a case where the downhill control and the extended regeneration control are jointly used, since the target remaining capacity is corrected to a value smaller than a usual low-side remaining capacity in the pre-use section, a possibility that the remaining capacity SOC may reach the remaining capacity upper limit decreases even if the extended regeneration control is executed during a period when the vehicle travels in the pre-use section and / or the downhill section.Consequently, since a possibility that a situation may occur in which electric power that could have been accumulated in the accumulator while the vehicle travels on the slope portion cannot be accumulated is reduced, fuel consumption of the vehicle can be further improved.
[0031] Furthermore, according to the above-mentioned target remaining capacity correction means, when the assist control means is configured to execute the congestion control as the look-ahead assist control, the target remaining capacity is corrected to a "value that is a second adjustment amount smaller than the high-side remaining capacity" in the second case. Therefore, even in a case where the congestion control and the extended regeneration control are jointly used, since the target remaining capacity in a section before arriving at the congestion section is corrected to a value smaller than a usual high-side remaining capacity, a possibility that the remaining capacity SOC may reach the remaining capacity upper limit decreases even if the extended regeneration control is executed in a period when the vehicle travels the section before arriving at the congestion section.Consequently, since a possibility that a situation may occur in which electric power that could have been accumulated in the accumulator while the vehicle travels the section before arriving at the congestion section cannot be accumulated, fuel consumption of the vehicle can be further improved.
[0032] In one embodiment of the device the target residual capacity correction device is configured such that the larger a first index value having a correlation with an amount of electric power charged into the accumulator by executing the extended regeneration control in a period when the vehicle travels the first section is in the first case, the larger the value to which the first adjustment amount is changed, and In the second case, the larger a second index value having a correlation with an electric power amount charged into the accumulator by an execution of the extended regeneration control in a period when the vehicle travels the second section, the larger a value to which the second adjustment amount is changed.
[0033] According to this configuration, since the target remaining capacity can be set according to an amount of electric power predicted to be charged into the battery by executing the enhanced regeneration control, the possibility that the remaining capacity SOC may reach the upper limit of the remaining capacity further decreases. Consequently, since the possibility that a situation may occur where electric power that could have been accumulated in the battery cannot be accumulated decreases, the fuel consumption of the vehicle can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a schematic diagram of a vehicle to which a control device for a hybrid vehicle (the present control device) according to an embodiment of the present invention is applied. Fig. 2 shows a nomogram to show a relationship of a rotational speed between a first motor, a second motor, an internal combustion engine, and a ring gear. Fig. 3 shows a graph to show a change in a residual capacity when a vehicle travels on a slope section. Fig. 4 shows a graph to show a change of a remaining capacity when a vehicle enters a congestion section. Fig. 5 is a diagram to schematically show a transition of a vehicle speed when a vehicle decelerates. Fig. 6 shows a graph to show a change in a remaining capacity in a case where slope control and extended regeneration control are executed together. Fig. 7 shows a graph to show a change in a remaining capacity in a case where congestion control and extended regeneration control are executed jointly. Fig. 8 is a graph for describing an operation of the present control apparatus in a case where slope control and extended regeneration control are jointly executed. Fig. 9 is a graph for describing an operation of the present control apparatus in a case where congestion control and extended regeneration control are jointly executed. Fig. 10 is a flowchart to show a slope control routine that includes a Fig. 1 CPU shown. Fig. 11 shows a flowchart to show a congestion control routine that implements the Fig. 1 CPU shown. Fig. 12 shows a flowchart to show an extended regeneration control routine that implements the Fig. 1 CPU shown. Fig. 13 shows a diagram to describe the extended regeneration control routine that Fig. 1 CPU shown. Fig. 14 is a flowchart to show a slope control routine that a CPU executes in the present control apparatus according to a modification. Fig. 15 is a flowchart to show a congestion control routine that a CPU executes in the present control apparatus according to a modification. Fig. 16 shows a look-up table referred to by a CPU in the present control apparatus according to another modification. DESCRIPTION OF THE PREFERRED EMBODIMENTS (Configuration)
[0034] Hereinafter, a control device for a hybrid vehicle (which may be referred to as a “present control device”) according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1, a hybrid vehicle 10 to which the present control apparatus is applied includes a first motor 21, a second motor 22, and an internal combustion engine 23.
[0035] The vehicle 10 further includes a power split mechanism 24, a storage battery 31, a boost converter 32, a first inverter 33, a second inverter 34, and an ECU 40. The ECU 40 corresponds to the present control device.
[0036] The first motor 21 and the second motor 22 are three-phase synchronous generator motors that can function as a generator or a motor, respectively.
[0037] The first motor 21 is primarily used as a generator. Furthermore, the first motor 21 cranks the internal combustion engine 23 when the internal combustion engine 23 starts. The second motor 22 is primarily used as a motor and can generate driving force for the vehicle 10 (torque for driving the vehicle). The internal combustion engine 23 can also generate driving force for the vehicle 10. The internal combustion engine 23 is a four-cylinder, four-stroke gasoline engine.
[0038] The power split mechanism 24 is a well-known planetary gear mechanism. The power split mechanism 24 includes a ring gear, a plurality of power split planetary gears, a plurality of reduction planetary gears, a first sun gear, a second sun gear, a first pinion carrier, and a second pinion carrier (all not shown).
[0039] The power-splitting planetary gear and the reduction planetary gear each mesh with a ring gear. The first sun gear meshes with the power-splitting planetary gear. The second sun gear meshes with the reduction planetary gear. The first planetary carrier maintains a plurality of the power-splitting planetary gears in a state where they can rotate about their own axes and rotate around the sun gear. The second planetary carrier maintains a plurality of the reduction planetary gears in a state where they can rotate about their own axes.
[0040] The ring gear is connected to the axle 25 by a counter gear arranged on a circumference of the ring gear such that torque can be transmitted between them. An output axle of the internal combustion engine 23 is connected to the first planetary carrier such that torque can be transmitted between them. An output axle of the first motor 21 is connected to the first sun gear such that torque can be transmitted between them. An output axle of the second motor 22 is connected to the second sun gear such that torque can be transmitted between them.
[0041] A relationship between a rotational speed (MG1 rotational speed) Nm1 of the first motor 21, an engine rotational speed NE of the engine 23 and a ring gear rotational speed Nr of the power split mechanism 24 and a rotational speed (MG2 rotational speed) Nm2 of the second motor 22 and the ring gear rotational speed Nr is expressed by a well-known nomogram shown in Fig. 2. Two lines shown in the nomogram can be referred to as a common operating line L1 and a common operating line L2.
[0042] According to the common operating line L1, a relationship between the MG1 rotation speed Nm1, the engine rotation speed NE, and the ring gear rotation speed Nr can be expressed by the following equation (1). Here, a gear ratio ρ1 is a ratio of the number of teeth of the first sun gear to the number of teeth of the ring gear (namely, ρ1 = the number of teeth of the first sun gear / the number of teeth of the ring gear). Nm1=Nr−(Nr−NE)×(1+ρ1) / ρ1
[0043] On the other hand, according to the common operating line L2, a relationship between the MG2 speed Nm2 and the ring gear speed Nr can be expressed by the following equation (2). Here, a gear ratio ρ2 is a ratio of the number of teeth of the second sun gear to the number of teeth of the ring gear (namely, ρ2 = the number of teeth of the second sun gear / the number of teeth of the ring gear). Nm2=Nr×(1+ρ2) / ρ2−Nr
[0044] Again with reference to Fig. 1, an axle 25 is connected to drive wheels 27 via a differential gear 26 so that torque can be transmitted between them.
[0045] The battery 31 is a secondary battery (in this example, a lithium-ion battery) that can be charged and discharged. Direct current (DC) electrical power output by the battery 31 undergoes voltage conversion (step-up) into high-voltage electrical power by the boost converter 32. The first inverter 33 converts the high-voltage electrical power into alternating current (AC) electrical power and supplies it to the first motor 21. Similarly, the second inverter 34 converts the high-voltage electrical power into AC electrical power and supplies it to the second motor 22.
[0046] In contrast, when the first motor 21 operates as a generator, the first inverter 33 converts generated AC electric power into DC electric power and supplies it to the boost converter 32 and / or the second inverter 34. Similarly, when the second motor 22 operates as a generator, the second inverter 34 converts generated AC electric power into DC electric power and supplies it to the boost converter 32 and / or the first inverter 33. The boost converter 32 step-downs the DC electric power supplied by the first inverter 33 and / or the second inverter 34 and supplies it to the battery 31. As a result, the battery 31 is charged.
[0047] The ECU 40 is an electronic control circuit that has a microcomputer including a CPU (central processing unit), a ROM (read-only memory), a RAM (random access memory), a non-volatile memory, and an interface, etc., as its main component. The ECU is an abbreviation for an electrical control unit. The CPU realizes various functions described below by executing instructions (routines) stored in the memory (ROM). The ECU 40 is connected to and controls the internal combustion engine 23, the boost converter 32, the first inverter 33, and the second inverter 34. The ECU 40 can be divided into a plurality of ECUs according to functions.In this case, the plurality of ECUs are configured to be able to exchange (communicate) data with each other through communication and a sensor system CAN (Controller Area Network).
[0048] The ECU 40 is connected to a crank angle sensor 51, an ammeter (current meter) 52, a vehicle speed sensor 53, an accelerator opening sensor 54, and a brake opening sensor 55.
[0049] The crank angle sensor 51 measures the rotational position of the crankshaft of the internal combustion engine 23 and outputs a signal indicating the degree CA of a crank angle. The ECU 40 calculates the engine speed NE of the internal combustion engine 23 based on the degree CA of the crank angle. The ammeter 52 outputs a signal indicating the electric current IB flowing through the battery 31. The ECU 40 calculates a remaining capacity SOC, which is the amount of electric power charged into the battery, based on the electric current IB.
[0050] The vehicle speed sensor 53 detects a rotational speed of the axle 25 and outputs a signal representing a traveling speed (vehicle speed) Vs of the vehicle 10. The accelerator opening sensor 54 outputs a signal representing an operating amount (accelerator operating amount) Ap of the accelerator pedal 56. The brake opening sensor 55 outputs a signal representing an operating amount (brake operating amount) Bp of the brake pedal 57.
[0051] Furthermore, the ECU 40 is connected to a GPS receiving device 61, a traffic information receiving device 62, a database 63, a display device 64 and a friction brake device 65.
[0052] The GPS receiver 61 acquires a current position (location) Pn of the vehicle 10 based on a signal from a GPS (Global Positioning System) satellite and transmits a signal representing the current position Pn to the ECU 40.
[0053] The traffic information receiving device 62 receives road information including traffic jam information and speed limit information, etc. around the current position Pn, which a road and traffic information communication system (VICS (registered trademark): Vehicle Information Communication System, not shown in the drawing) offers via a radio beacon and an FM multiplex broadcast, etc.
[0054] The database 63 includes a hard disk (HDD) that stores map data (map information). The map data includes information about a "node" such as a point of an intersection and a dead end, etc., a "link" connecting the nodes, and a "facility" along the link such as a building and a parking lot, etc. Furthermore, the map data includes a length of a section of a road corresponding to each link, position coordinates of a node at one end (start point) and another node at the other end (end point) of a link, and an average gradient of a road corresponding to a link.The average gradient is a ratio of a “height difference between both ends of a road corresponding to a link” to a “distance between positions at both ends of a road corresponding to a link (namely, a distance between positions of both nodes)”.
[0055] The display device 64 is arranged in a center console (not shown) provided in a vehicle interior of the vehicle 10. The display device 64 includes a display and can display a map based on map data and the current position Pn of the vehicle 10, etc., on the display.
[0056] The display of the display device 64 functions as a touch panel that receives operational input. Furthermore, the display device 64 includes a pronunciation device (not shown). The display device 64 can reproduce an audible signal and an announcement, etc., according to an instruction from the ECU 40.
[0057] When a driver of the vehicle 10 inputs a destination using the display device 64, the ECU 40 searches for a path (planned route) from the current position Pn to the destination based on a map database. The planned route is formed by a set of nodes. The ECU 40 can provide guidance to a driver according to the planned route using an indication on the display device 64 and a voice generated by the pronunciation device.
[0058] The friction brake device 65 includes a master cylinder that pressurizes hydraulic oil by the stepping force of the brake pedal 57, a brake device including a well-known wheel cylinder provided in each wheel, and a brake actuator. The brake actuator applies a friction force to a brake disc by adjusting the oil pressure supplied to the wheel cylinder. Consequently, the ECU 40 can adjust the friction braking force generated at each wheel cylinder by controlling the brake actuator. (Operation)
[0059] Next, an operation of the present control device (ECU 40) will be described. The present control device is a device that solves a problem that occurs when "slope control and / or congestion control" and "extended regeneration control" are used together, which will be described below. First, a control that is a prerequisite for these controls will be described, followed by a description of these controls. In the present specification, the "slope control and congestion control" may be referred to as "look-ahead assist control" or simply as "assist control." 1. Drive force control by the ECU
[0060] The hybrid vehicle 10 controls the first motor 21, the second motor 22, and the internal combustion engine 23 in conjunction with each other. A basic content of this control is well known and is described, for example, in Japanese Patent Application Laid-Open No. JP 2009-126450 A (US Patent Application No. US 2010 / 0241297 A1) and Japanese Patent Laid-Open No. JP H09-308012 A (US Patent No. US 6,131,180 A, filed on March 10, 1997), etc.
[0061] In short, the ECU 40 determines a ring gear request torque Tr*, which is a target value of a torque (ring gear generation torque) Tr acting on a ring gear, based on the accelerator operation amount Ap and the vehicle speed Vs. Since the ring gear generation torque Tr has a proportional relationship with a torque acting on the drive wheels 27, the larger the torque acting on the drive wheels 27 becomes, the larger the ring gear generation torque Tr becomes. Therefore, the ring gear request torque Tr* is also a request driving force required for the vehicle 10. The ECU 40 controls the internal combustion engine 23, the boost converter 32, the first inverter 33, and the second inverter 34 such that the ring gear generation torque Tr becomes equal to the ring gear request torque Tr* and the remaining capacity SOC becomes identical (almost) to the target remaining capacity SOC*.
[0062] For example, when the remaining capacity SOC is approximately identical to the target remaining capacity SOC*, in an operating range where the operating efficiency of the internal combustion engine 23 is high, the ECU 40 causes both the internal combustion engine 23 and the second motor 22 to generate output power, with the first motor 21 generating electric power with a portion of the engine output power Pe generated by the internal combustion engine 23. In this case, the electric power generated by the first motor 21 is supplied to the second motor 22.
[0063] When the remaining capacity SOC is lower than the target remaining capacity SOC*, the ECU 40 increases the engine output Pe to increase a generation amount of electric power by the first motor 21. Thereby, the remaining capacity SOC increases and approaches the target remaining capacity SOC*.
[0064] In contrast, the ECU 40 stops operation of the internal combustion engine 23 and causes only the second motor 22 to generate output power in an operation range where the operation efficiency of the internal combustion engine 23 is low, such as when the vehicle 10 starts moving and when the vehicle 10 is running at a low load, etc. In this case, the remaining capacity SOC decreases.
[0065] Incidentally, in order to prevent premature deterioration of the secondary battery 31, it is desirable to maintain the remaining capacity SOC between a lower limit remaining capacity Smin and an upper limit remaining capacity Smax. Therefore, when the remaining capacity SOC becomes lower than the lower limit remaining capacity Smin, the ECU 40 operates the internal combustion engine 23 and causes the first motor 21 to generate electric power with the output of the internal combustion engine 23 to perform "forced charging" of the secondary battery 31. This causes the remaining capacity SOC to become greater than the lower limit remaining capacity Smin.
[0066] Furthermore, when the remaining capacity SOC becomes higher than the upper limit remaining capacity Smax, the ECU 40 stops the operation of the internal combustion engine 23 even in an operating range where the operating efficiency of the internal combustion engine 23 is high, except for a case where high output and high torque are required, and causes only the second motor 22 to generate output. This makes the remaining capacity SOC smaller than the upper limit remaining capacity Smax. 2. Brake force control by the ECU
[0067] When a driver requires braking force to decelerate the vehicle 10, the driver performs an operation to set both the accelerator operation amount Ap and the brake operation amount Bp to "0," or an operation to set the accelerator operation amount Ap to "0" and increase the brake operation amount Bp. When braking force is required, the ECU 40 determines a target braking force based on the accelerator operation amount Ap, the brake operation amount Bp, and the vehicle speed Vs, and generates "regenerative braking force and friction braking force" so that the actual braking force becomes almost identical to the target braking force. At this time, if the regenerative braking force is insufficient for the target braking force, the deficit is compensated with braking force.
[0068] When the ECU 40 generates regenerative braking force, the ECU 40 causes the first motor 41 and / or the second motor 22 to generate electric power. In other words, the ECU 40 converts kinetic energy of the vehicle 10 into electric power using the first motor 21 and / or the second motor 22. The generated electric power is charged into the secondary battery 31, thereby increasing the residual capacity SOC.
[0069] When a frictional braking force is generated, the ECU 40 controls the frictional braking device 65 to apply a frictional braking force to each of the wheels of the vehicle 10. In other words, the ECU 40 converts kinetic energy of the vehicle 10 into heat energy using the frictional braking device 65. The aforementioned "driving force control, braking force control, and residual capacity SOC control in conjunction therewith" are achieved by the CPU of the ECU 40 executing a "vehicle travel control routine" not shown. 3. Slope control
[0070] When a vehicle 10 travels down a slope, a driver often requests a large braking force. Consequently, as the amount of regenerated electric power becomes large, the remaining capacity SOC may increase and reach the remaining capacity upper limit Smax. When the remaining capacity SOC reaches the remaining capacity upper limit Smax, regenerative braking cannot be performed from the standpoint of protecting the battery 31. As a result, since braking is performed by the friction brake device 65, kinetic energy of the vehicle 10 is not converted into electric energy but is converted into heat energy. As a result, when the vehicle 10 travels down a slope, a situation may occur in which electric power that can be accumulated in the battery 31 cannot be accumulated.
[0071] Therefore, when a downhill section (which may be referred to as a "target downhill section" hereinafter) that satisfies a "downhill section condition" mentioned later exists in a planned travel route of the vehicle 10, the ECU 40 executes control in which the remaining capacity SOC has been decreased before a start point of the downhill section, that is, downhill control.
[0072] Specifically, after a planned travel route of the vehicle 10 is determined by a driver operating the display device 64, the CPU of the ECU 40 judges whether a downhill section (target downhill section) exists in the planned travel route. The target downhill section is a section where the regenerated electric power amount obtained by the vehicle 10 traveling the section is expected to be greater than an "electric power amount S20 equivalent to a predetermined proportion (for example, 20%) of the maximum charge amount (namely, an amount of accumulated electricity when the remaining capacity SOC is 100%) of the secondary battery 31." [Slope section condition]
[0073] A distance between a start point and an end point of a slope segment is longer than a distance threshold Dth1, an altitude of the start point is higher than an altitude of the end point beyond an altitude threshold Hth (the altitude of the start point is higher than the altitude of the end point, where a magnitude of a difference in altitude between the start point and the end point is greater than the threshold Hth).
[0074] For example, in an example shown in Fig. 3, links constituting a planned travel route of the vehicle 10 are Link 1 to Link 8. Furthermore, a distance Dd of a section consisting of Link 4 to Link 6 is longer than the distance threshold Dth1. In addition, an altitude of a start point of the section consisting of Link 4 to Link 6 (namely, a start point D3 of Link 4) is H1, an altitude of the end point of the section consisting of Link 4 to Link 6 (namely, an end point D6 of Link 6) is H2, and an altitude H1 of the start point is higher than the altitude H2 of the end point (ΔH = H1 - H2 > Hth), beyond the altitude threshold Hth. Consequently, the section formed by Link 4 to Link 6 corresponds to a downhill section (destination downhill section). Roads corresponding to link 1 to link 3, link 7 and link 8 are flat roads.
[0075] In a case where the CPU judges that the downhill section (target downhill section) exists in the planned travel route, the CPU starts downhill control when the vehicle 10 arrives at a point (point D1a) a predetermined pre-use distance (first distance) Dp before the starting point (point D3) of the downhill section. The downhill control is a control in which the target remaining capacity SOC*, which is set to the standard remaining capacity Sn at a normal time, is set to the low-side remaining capacity Sd, which is a predetermined value ΔSd smaller than the standard remaining capacity Sn (see polygonal line Lp1 in Fig. 3).
[0076] When the vehicle 10 arrives at the end point (point D6) of the downhill section, the CPU terminates the downhill control by returning the target remaining capacity SOC* to the standard remaining capacity Sn from the low-side remaining capacity Sd.
[0077] A section from the "point (point D1a) the pre-use distance Dp before the starting point (point D3) of the slope section" to the "starting point (point D3) of the slope section" can be referred to as a pre-use section. Furthermore, a combined section (point D1a to point D6) of the pre-use section and the slope section can be referred to as a "slope control section."
[0078] As a result, when the slope control is executed, the remaining capacity SOC changes as shown by a solid line LC1 in Fig. 3. On the other hand, when the slope control is not executed, the remaining capacity SOC changes as shown by a dashed line LC2 in Fig. 3. As can be seen from Fig. 3, since the remaining capacity SOC reaches the remaining capacity upper limit Smax at a time when the vehicle 10 arrives at a point D5a in the link 6, in a case where the slope control is not executed, regenerative electric power cannot be collected after the point D5a.
[0079] In contrast, when the downhill control is executed, since the target remaining capacity SOC* is set to the low-side remaining capacity Sd in the pre-use section, the remaining capacity SOC decreases deeper than the standard capacity Sn. Consequently, even if the remaining capacity SOC increases in the downhill section, the remaining capacity SOC does not reach the upper limit remaining capacity Smax. As a result, the amount of regenerative electric power that can be collected in the downhill section becomes large. Furthermore, priority is given to EV running over HV running (running using output power of the second motor 22 and the internal combustion engine 23) in the pre-use section. Consequently, fuel consumption of the vehicle 10 is improved.
[0080] A section in which the target residual capacity SOC* is set to the low-side residual capacity Sd (namely, a section in which slope control is performed) only needs to include a section from the start point of the pre-use section to the end point of the pre-use section (namely, the start point of the downhill section), where the target residual capacity SOC* can be returned to the standard residual capacity Sn in the middle of the downhill section.In other words, what is required is only to set the target remaining capacity SOC* to the low-side remaining capacity Sd in the first section, which includes at least a "section from the slope control start point to the slope section start point" of a section from the slope control start point (pre-use section start time), which is the predetermined first distance before the slope section start point included in the planned travel route, to the slope section end point. The above is an abbreviated version of the slope control. 4. Congestion control
[0081] In contrast, when the vehicle 10 travels through a congested section, the opportunity to travel using only the output of the second motor 22 without using the output of the internal combustion engine 23 (EV travel opportunity) increases. Furthermore, the amount of regenerated electric power in the congested section is not large. As a result, since a case occurs where the remaining capacity SOC decreases and reaches the lower limit of the remaining capacity Smin while the vehicle 10 travels through the congested section, and accordingly, "compulsory charging" is performed, fuel consumption deteriorates.
[0082] Then, the ECU 40 executes control in which the remaining capacity SOC has been increased before the start point of the congestion section, that is, the congestion control, when a congestion section satisfying the “congestion section condition” described below (which may be referred to as a “target congestion section” hereinafter) exists in the planned travel route of the vehicle 10.
[0083] Specifically, after a planned travel route is determined by a driver's operation, the CPU of the ECU 40 judges whether a congestion section (target congestion section) exists in the planned travel route. The target congestion section is a section where the remaining capacity SOC is expected to be reduced by an electric power amount greater than an "electric power amount S20 equivalent to a predetermined proportion (for example, 20%) of the maximum charge amount of the secondary battery 31" by the vehicle 10 traveling in the section. [Congestion section condition]
[0084] It is a section that a road and traffic information communication system identifies as delayed (congested) (for example, a section in which an average vehicle speed is several km / h or less), where a distance between a start point and an end point of the section is longer than a distance threshold Dth2.
[0085] For example, in an example shown in Fig. 4, links constituting a planned travel route of the vehicle 10, Link 1 to Link 8, wherein roads corresponding to the respective links are flat roads. Further, a traffic jam occurs in a section between a point D3b and a point D6. A distance Dj between a start point D3b and an end point D6 of this section is longer than a distance threshold Dth2. Therefore, a section from the start point D3b to the end point D6 is a congestion section (target congestion section). When the above-mentioned slope control and congestion control are not executed, the CPU sets the target remaining capacity SOC* to the standard remaining capacity Sn.
[0086] When the CPU judges that the congestion section (target congestion section) exists in the planned travel route, the CPU starts congestion control when the vehicle 10 arrives at a point (point D1b; a congestion control start point) a predetermined precharge distance (second distance) Dc before the start point (point D3b) of the congestion section. The congestion control is a control in which the target remaining capacity SOC*, which is set to the standard remaining capacity Sn at a normal time, is set to a high-side remaining capacity Sh that is a predetermined value ΔSh greater than the standard remaining capacity Sn (see polygonal line Lp2 in Fig. 4).
[0087] When the vehicle 10 arrives at the starting point (point D3b) of the congestion section, the CPU terminates the congestion control by returning the target remaining capacity SOC* to the standard remaining capacity Sn from the high-side remaining capacity Sh.
[0088] A section from the “point (point D1b) the pre-charge distance Dc before the starting point (point D3b) of the congestion section” to the “starting point (point D3b) of the congestion section” may be referred to as a pre-charge section or a second section.
[0089] As a result, when the congestion control is executed, the remaining capacity SOC changes as shown by a solid line Lc3 in Fig. 4. On the other hand, when the congestion control is not executed, the remaining capacity SOC changes as shown in a dashed line Lc4 in Fig. 4. As can be seen from Fig. As can be seen from Fig. 4, since the remaining capacity SOC reaches the remaining capacity lower limit Smin at a time when the vehicle 10 arrives at a point D5b in the link 6, in a case where slope control is not executed, the CPU executes forced charging using an output of the internal combustion engine 23. As a result, fuel consumption of the vehicle 10 deteriorates.
[0090] In contrast, when congestion control is executed, since the target remaining capacity SOC* is set to the high-side remaining capacity Sh in the pre-charging section, the remaining capacity SOC increases higher than the standard remaining capacity Sn. As a result, even if the remaining capacity SOC decreases in the congestion section, there is a high possibility that the remaining capacity SOC will not reach the lower limit remaining capacity Smin. As a result, since it becomes unlikely that forced charging is performed using an output of the internal combustion engine 23, fuel consumption of the vehicle 10 is improved. 5. Advanced regeneration control
[0091] For example, when a sudden hard braking operation is performed immediately before a stop line in a case where a driver stops a vehicle at an intersection, etc., it is necessary to temporarily output a large braking force to wheels. Since there is an upper limit in the electric charge current that can be passed through the accumulator 31, a regenerative braking force is also limited so that an electric charge current does not exceed the upper limit. Furthermore, since a demand braking force may temporarily exceed the maximum value of a regenerative braking force at the time of a sudden hard braking operation, a braking force insufficiency is compensated with a friction braking force by the friction braking device 65.Consequently, if a driver does not perform a heavy sudden braking operation by starting a braking operation earlier, an energy that could have been accumulated in the accumulator 31 as electric energy by regenerative braking is wasted in the form of heat energy generated by the friction brake device 65 by the heavy sudden braking operation.
[0092] In order to reduce such useless heat energy release, the CPU of the ECU 40 predicts a situation in which a driver performs a braking operation based at least on a current position Pn of a vehicle (own vehicle), and performs an accelerator-off induction at a predetermined timing (refer to point P1 in Fig. 5). The accelerator off induction serves to execute a notification to prompt a driver to release the accelerator pedal (reset a stepping force to the accelerator pedal) using the display device 64. Through the accelerator off induction, almost all drivers release the accelerator pedal 56.
[0093] At or after a point in time (see point P2 in Fig. 5) a predetermined time (Ts second) after the start time (refer to the point P1) of the accelerator-off induction, the CPU increases a regenerative braking force when the accelerator pedal 56 is released (a regenerative braking force equivalent to that called engine braking) more than usual and increases a regenerated energy at the accumulator 31. As a result, since the vehicle speed Vs at the time when a driver starts a braking operation (refer to a point P3 according to Fig. 5), the braking operation amount Bp becomes small thereafter. Consequently, since much of the demand braking force can be covered with regenerative braking force, the amount of heat energy emitted (released) by the friction brake device 65 can be reduced, and more electric energy can be collected. Consequently, fuel consumption of the vehicle 10 is improved.
[0094] Specifically, the CPU of the ECU 40 learns a position (location) on a map where a driver releases a brake pedal with a high frequency based on the driver's daily driving operation and registers the learned position in a non-volatile memory as a target deceleration end position. Furthermore, the CPU registers a vehicle speed Vs at the time of arrival at the target deceleration end position in a non-volatile memory as a target deceleration end vehicle speed in association with the target deceleration end position. As a position learned as the target deceleration end position with a high possibility, a stop position at an intersection point and a position where a driver shifts his / her foot from a brake pedal to an accelerator pedal when starting to escape from a curved lane in a case where the lane is curved, etc., can be cited.
[0095] The CPU judges whether the target deceleration end position registered as above exists within a predetermined distance (for example, hundreds of meters) from a current position of the vehicle 10 on a road in a planned travel route of the vehicle 10. At this time, if the judgment result is affirmative, the CPU sets the target deceleration end position as a target deceleration end position P0* and reads a target deceleration end vehicle speed V0* corresponding to the set target deceleration end position P0* from a non-volatile memory.
[0096] The CPU determines a timing for starting an accelerator-off induction based on the target deceleration end position P0* and the target deceleration end vehicle speed V0* according to a procedure explained in detail below. The CPU starts the accelerator-off induction at an accelerator-off induction timing (see a point P1 in Fig. 5).
[0097] Further, the CPU sets the regenerative braking force to a value larger than the “regenerative braking force when the accelerator pedal 56 is released at a normal time”, thereby causing the vehicle to decelerate from a time Ts (see a point P2 in Fig. 5) is increased when the accelerator pedal 56 is actually released after the accelerator-off induction timing and Ts seconds have passed since the accelerator-off induction timing. Namely, the CPU increases regenerated energy after time Ts. Thus, the "extended regeneration control" is control in which regenerated energy is increased so that deceleration of a vehicle becomes large when the accelerator-off induction is executed and the accelerator pedal 56 is released thereafter.
[0098] Since a vehicle speed at a time of braking operation when a driver depresses the brake pedal 57 becomes small by this extended regeneration control (see a point P3 in Fig. 5), the amount of heat energy released at the friction brake device 65 by subsequent braking operation decreases. In other words, more electrical energy can be collected through regenerative braking. As a result, fuel consumption of the vehicle 10 can be improved.
[0099] 6. Problems when slope control and / or accumulation control are used with the extended regeneration control
[0100] Incidentally, if the presence of the slope section (target slope section) is expected on the planned route, the CPU executes the slope control. As indicated by a solid line Lp10 in Fig. As shown in FIG. 6, when the vehicle 10 arrives at a starting point (D1a) of a pre-use section, the CPU changes the target remaining capacity SOC* to the low-side remaining capacity Sd from the standard remaining capacity Sn and starts the slope control. As a result, as shown by a dashed line Lc10, the remaining capacity SOC decreases and approaches the low-side remaining capacity Sd in the pre-use section.
[0101] However, as it is shown by quadrilaterals in Fig. 6, the extended regeneration control may be executed once or more during a period when the slope control is executed (in the slope control section).
[0102] In this case, when the extended regeneration control is executed in the pre-use section, the remaining capacity SOC does not sufficiently decrease to the low-side remaining capacity Sd. Furthermore, when the extended regeneration control is executed in the downhill section, an increase amount of the remaining capacity SOC is increased beyond an expectation. As a result, a case occurs where the remaining capacity SOC reaches the upper limit remaining capacity Smax (see a point Pa). As a result, a situation occurs where electric energy that could be accumulated in the accumulator 31 cannot be accumulated.
[0103] On the other hand, if the presence of the traffic jam section (target traffic jam section) is expected in the planned route, the CPU executes the traffic jam control. As indicated by a solid line Lp11 in Fig. As shown in Figure 7, when the vehicle 10 arrives at a starting point (D1b) of the pre-charge section, the CPU changes the target remaining capacity SOC* to the high-side remaining capacity Sh from the standard remaining capacity Sn and starts the congestion control. As a result, as shown by a dashed line Lc11, the remaining capacity SOC increases and approaches the high-side remaining capacity Sh in the pre-charge section.
[0104] As it is through quadrilaterals in Fig. However, as shown in FIG. 7, the extended regeneration control may be executed once or more during a period when the vehicle 10 travels in the pre-charge section. In this case, since the remaining capacity SOC has almost become the high-side remaining capacity Sh, a case occurs where the remaining capacity SOC reaches the upper limit remaining capacity Smax (see a point Pc). In this case, it means that the internal combustion engine 23 has been unnecessarily operated in the pre-charge section to bring the remaining capacity SOC close to the high-side remaining capacity Sh. Furthermore, since the remaining capacity SOC reaches the upper limit remaining capacity Smax, it means that electric power that can be collected at and after that time is rendered useless.
[0105] 7. Parallel use of slope control and / or congestion control with the extended regeneration control by the present control device
[0106] The present control device solves the above-mentioned problem as described below. As described in Fig. As shown in FIG. 8, the present control device anticipates an increase in the remaining capacity SOC in association with an increase in the regenerated electric power amount due to the extended regeneration control, and sets the target remaining capacity SOC* in the pre-use section to a "value Sd' that is the first adjustment amount ΔS1 smaller than the low-side remaining capacity Sd" when the extended regeneration control is expected to be executed while the vehicle 10 is traveling on the slope control section. This value Sd' may be referred to as a corrected low-side remaining capacity.
[0107] Since the residual capacity SOC decreases sufficiently in the pre-use section, as shown by a solid line Lc12 in Fig. As shown in FIG. 8, even when the extended regeneration control is executed in the downhill section (see a point Pb), the possibility that the remaining capacity SOC may reach the upper limit remaining capacity Smax is low. As a result, the possibility that a situation may occur where electric energy that could have been accumulated in the accumulator 31 cannot be accumulated can be reduced.
[0108] Furthermore, you can see how it is in Fig. As shown in FIG. 9, the present control device anticipates an increase in the remaining capacity SOC in association with an increase in regenerated energy due to the extended regeneration control, and sets the target remaining capacity SOC* in the pre-charge section to a "value Sh' that is larger than the standard remaining capacity SOC* and the second adjustment amount ΔS2 is smaller than the high-side remaining capacity Sh" when the extended regeneration control is expected to be executed in a period when the vehicle 10 travels in the pre-charge section for congestion control. This value Sh' may be referred to as a corrected high-side remaining capacity.
[0109] Accordingly, as shown by a solid line Lc13 in Fig. As shown in FIG. 9, even when the extended regeneration control is executed in the pre-charge section, a possibility that the remaining capacity SOC may reach the upper limit remaining capacity Smax is low. As a result, a possibility that the internal combustion engine 23 may generate useless output power to bring the remaining capacity SOC close to the high-side remaining capacity Sh, which is not corrected and thus remains high, and a possibility that a situation may occur where electric energy that could have been accumulated in the secondary battery 31 cannot be accumulated can be reduced. (Specific operation)
[0110] Next, a specific operation of the present control device will be explained. The CPU of the ECU 40 repeatedly executes a routine described in Fig. 10, at a predetermined time interval. Consequently, when it reaches a predetermined timing, the CPU starts processing from step S100 in Fig. 10 and proceeds to step S101, obtaining a planned travel route of the vehicle 10. Next, the CPU proceeds to step S102 and judges whether the "downhill section (target downhill section) satisfying the above-mentioned downhill section condition" is currently included in the planned travel route of the vehicle 10.
[0111] If the downhill section is not included in the planned travel route, the CPU judges "No" in step S102 and proceeds to step S103, setting the target remaining capacity SOC* to the standard remaining capacity Sn. Thereafter, the CPU proceeds to step S109, terminating this routine once. As a result, by executing a "vehicle travel control routine" not shown, the CPU controls the first motor 21, the second motor 22, and the internal combustion engine 23 so that a driving force (torque) required for the vehicle 10 is satisfied and the remaining capacity SOC is brought close to the standard remaining capacity Sn.
[0112] In a case where the downhill section is included in the planned travel route at a time when the CPU executes processing according to step S102, the CPU judges "Yes" in step S102. Then, the CPU proceeds to step S104 and judges (predicts) whether a point where the extended regeneration control is executed exists in the downhill control section corresponding to the downhill section (a section consisting of a combination of the pre-use section and the downhill section). More specifically, the CPU judges whether the above-mentioned target deceleration end position exists in a section within a predetermined distance (for example, hundreds of meters) from the current position of the vehicle 10 on the planned travel route of the vehicle 10, and judges whether the target deceleration end position exists in the downhill control section if the target deceleration end position exists.When the point at which the extended regeneration control is executed is present in the slope control section, it can be assumed that an electric power amount charged into the accumulator 31 by the extended regeneration control in the slope control section is larger than the first threshold electric power amount.
[0113] When the CPU judges that no point where the extended regeneration control is executed exists in the slope control section, the CPU proceeds to step S105 from step S104, sets the low-side remaining capacity Sd to a “value obtained by subtracting a predetermined value ΔSd from the standard remaining capacity Sn (= Sn - ΔSd)” and proceeds to step S107.
[0114] On the other hand, when the CPU judges that a point where the extended regeneration control is executed exists in the slope control section, the CPU proceeds to step S106 from step S104, sets the low-side remaining capacity Sd to the “corrected low-side remaining capacity Sd (=(Sn - ΔSd) - ΔS1)” and proceeds to step S107.
[0115] The CPU judges in step S107 whether a current position of the vehicle 10 is in the downhill control section (namely, the pre-use section and the downhill section). If the current position of the vehicle 10 is in the downhill control section, the CPU judges "Yes" in step S107 and proceeds to step S108, where it sets the target remaining capacity SOC* to the "low-side remaining capacity Sd set in step S105 or step S106." On the other hand, if the current position of the vehicle 10 is not in the downhill control section, the CPU judges "No" in step S107 and proceeds to step S103, where it sets the target remaining capacity SOC* to the standard remaining capacity SOC*.
[0116] As a result, when the current position of the vehicle 10 is not in the slope control section, by the CPU executing the "vehicle travel control routine" not shown, the first motor 21, the second motor 22, and the internal combustion engine 23 are controlled so that the driving force (torque) required for the vehicle 10 is satisfied and the remaining capacity SOC is brought close to the standard remaining capacity Sn. Furthermore, when the current position of the vehicle 10 is in the slope control section, the first motor 21, the second motor 22, and the internal combustion engine 23 are controlled so that the driving force (torque) required for the vehicle 10 is satisfied and the remaining capacity SOC is brought close to the "low-side remaining capacity Sd set in step S105 or step S106."
[0117] As apparent from the above description, since the remaining capacity SOC at the downhill starting point is sufficiently reduced even in a case where the extended regeneration control is executed in the downhill control section, a possibility that the remaining capacity SOC may reach the upper limit remaining capacity Smax in the downhill section can be reduced. Consequently, a probability of occurrence of a situation in which electric energy that could have been accumulated in the battery 31 cannot be accumulated can be reduced.
[0118] Furthermore, the CPU of the ECU 40 repeatedly executes a routine that Fig. 11, at a predetermined time interval. Consequently, when it reaches a predetermined timing, the CPU starts processing from step S110 in Fig. 10 and proceeds to step S111, where it acquires road information including the planned travel route of the vehicle 10 and congestion information. Next, the CPU proceeds to step S112, where it judges whether the "congestion section that satisfies the above-mentioned congestion section condition (target congestion section)" currently exists in the planned travel route of the vehicle 10.
[0119] If the congestion section is not included in the planned travel route, the CPU judges "No" in step S112 and proceeds to step S113, setting the target remaining capacity SOC* to the standard remaining capacity Sn. Thereafter, the CPU proceeds to step S119, terminating this routine once. As a result, by the CPU executing a "vehicle travel control routine" (not shown), the first motor 21, the second motor 22, and the internal combustion engine 23 are controlled so that the driving force (torque) required for the vehicle 10 is satisfied and the remaining capacity SOC is brought close to the standard remaining capacity Sn.
[0120] In a case where the congestion section is included in the planned travel route at a time when the CPU executes the processing of step S112, the CPU judges "Yes" in step S112. Then, the CPU proceeds to step S114, where it judges (predicts) whether a point at which the extended regeneration control is executed exists in the pre-charge section corresponding to the congestion section. More specifically, the CPU judges whether the above-mentioned target deceleration end position exists in a section within a predetermined distance (for example, hundreds of meters) from the current position of the vehicle 10 in the planned travel route of the vehicle 10, and judges whether the target deceleration end position is in the pre-charge section if the target deceleration end position exists.When a point at which the extended regeneration control is executed exists in the pre-charge section, it can be assumed that the electric power amount charged into the battery 31 by the extended regeneration control in the pre-charge section is larger than the second threshold electric power amount.
[0121] When the CPU judges that no point at which the extended regeneration control is executed exists in the precharge section, the CPU proceeds to step S115 from step S114, sets the high-side remaining capacity Sh to a “value obtained by adding a predetermined value ΔSh to the standard remaining capacity Sn (= Sn + ΔSh)” and proceeds to step S117.
[0122] On the other hand, when the CPU judges that a point at which the extended regeneration control is executed exists in the congestion section, the CPU proceeds to step S116 from step S114, sets the high-side remaining capacity Sh to the “corrected high-side remaining capacity Sh' (= (Sn + ΔSh) - ΔS2)” and proceeds to step S117.
[0123] The CPU judges in step S117 whether the current position of the vehicle 10 is in the pre-charge section. If the current position of the vehicle 10 is in the pre-charge section, the CPU judges "Yes" in step S117 and proceeds to step S118, where it sets the target remaining capacity SOC* to the "high-side remaining capacity Sh set in step S115 or step S116." On the other hand, if the current position of the vehicle 10 is not in the pre-charge section, the CPU judges "No" in step S117 and proceeds to step S113, where it sets the target remaining capacity SOC* to the standard remaining capacity SOC*.
[0124] As a result, when the current position of the vehicle 10 is not in the pre-charge section, by the CPU executing a "vehicle running control routine" not shown, the first motor 21, the second motor 22, and the internal combustion engine 23 are controlled so that the driving force (torque) required for the vehicle 10 is satisfied and the remaining capacity SOC is brought close to the standard remaining capacity Sn. Furthermore, when the current position of the vehicle 10 is in the pre-charge section, the first motor 21, the second motor 22, and the internal combustion engine 23 are controlled so that the driving force (torque) required for the vehicle 10 is satisfied and the remaining capacity SOC is brought close to the "high-side remaining capacity Sh set in step S115 or step S116."
[0125] As apparent from the above description, since the remaining capacity SOC in the pre-charge section is not excessively increased even in a case where the extended regeneration control is executed in the pre-charge section, a possibility that the remaining capacity SOC may reach the remaining capacity upper limit Smax in the pre-charge section can be reduced. Consequently, in the pre-charge section, a possibility that a situation may occur in which the internal combustion engine 23 generates useless output power and electric energy that could have been accumulated in the battery 31 cannot be accumulated can be reduced.
[0126] Furthermore, the CPU of the ECU 40 repeatedly executes a routine (Extended Regeneration Control Routine) which Fig. 12 at a predetermined time interval. However, the CPU also executes the routine in a case where Fig. 12 is executed, if it comes at a time or timing when another routine is being executed, the (other) routine is terminated by interrupt processing.
[0127] When it comes to a predetermined timing, the CPU starts processing from step S120 in Fig. 12 and judges whether a distance to the "nearest target deceleration end position P0* on the planned travel route of the vehicle 10" from a "current position of the vehicle 10" has become a predetermined distance or less. This predetermined distance has been set to a distance such that a timing when the vehicle 10 arrives at a position this position before the latest target deceleration end position P0* is sufficiently earlier than a timing when the accelerator-off induction is executed. The CPU repeats the processing of step S121 until the judgment in step S121 becomes affirmative.
[0128] If the CPU judges “Yes” in step S121, the CPU proceeds to step S122, where it calculates a position (accelerator-off induction position) Ps at which accelerator-off induction is carried out, based on the target deceleration end position P0* and the target deceleration end vehicle speed V0* (refer to Fig. 13).
[0129] Specifically, as described above, the target deceleration end position P0* is a position where a vehicle is predicted to stop or a position where deceleration of a vehicle on a curved road is predicted to be completed, and is registered in a non-volatile memory by learning. The target deceleration end vehicle speed V0* is zero when the target deceleration end position P0* is, for example, a stop position, and is registered in the non-volatile memory by learning.
[0130] The CPU calculates “a target braking position Pb* and a target braking vehicle speed Vb*” which are Fig. 13, based on the target deceleration end position P0* and the target deceleration end vehicle speed V0*. The target braking position Pb* is equivalent to a brake pedal operation start position in a case where an ideal driver (model driver) who does not waste energy decelerates the vehicle 10 at a predetermined deceleration such that the vehicle speed when the vehicle 10 reaches the target deceleration end position P0* becomes identical to the target deceleration end vehicle speed V0*.
[0131] Therefore, when the target deceleration end vehicle speed V0* is set, a distance from the target braking position Pb* to the target deceleration end position P0* (hereinafter referred to as a "target braking distance Db*") and the target braking vehicle speed Vb* are determined once. Then, the ECU 40 stores a predetermined relationship between the target deceleration end vehicle speed V0* and each of the target braking distance Db* and the target braking vehicle speed Vb* in a ROM in the form of a look-up table. Then, the CPU calculates the target braking distance Db* and the target braking vehicle speed Vb* by applying an actual target deceleration end vehicle speed V0* to the look-up table. Further, the CPU calculates the target braking position Pb* from the target braking distance Db* and the target deceleration end position P0*.
[0132] Next, based on an “ideal deceleration Ge desired during the extended regeneration control,” the target braking vehicle speed Vb*, and a current vehicle speed Va of the vehicle 10, the CPU obtains an extended regeneration distance De, which is a distance for which the vehicle 10 should be decelerated at the ideal deceleration Ge, as described below.
[0133] The ideal deceleration Ge is a deceleration obtained at the time of accelerator off, which is previously set to a larger deceleration (negative acceleration with a large magnitude) than a deceleration obtained at the time of accelerator off while driving without extended regeneration control (normal driving). Specifically, the deceleration at the time of accelerator off during normal driving changes depending on the vehicle speed.Consequently, the CPU calculates the ideal deceleration Ge by applying an average value of the actual vehicle speed Va of the vehicle 10 and the target braking vehicle speed Vb* to the lookup table that specifies a relationship between a vehicle speed and the ideal deceleration Ge as a vehicle speed as an argument of the lookup table.
[0134] From the above, since the target braking vehicle speed Vb* and the ideal deceleration Ge are obtained, the CPU obtains the extended regeneration distance De based on the following two equations (see Fig. 13). In the following equations, a = -Ge. Vb*=Va+a⋅t De=Va⋅t+(1 / 2)⋅a⋅t2
[0135] Furthermore, the CPU calculates a position (extended regeneration control starting point) Pj at which the extended regeneration control should be started based on the extended regeneration distance De and the target braking position Pb*.
[0136] The timing when the accelerator-off induction is executed is set to the predetermined time ts earlier than a time T when the vehicle 10 arrives at the extended regeneration control start point Pj. Therefore, the CPU calculates a distance obtained by multiplying the current vehicle speed Va of the vehicle 10 by the time ts as an induction period distance Dy, obtaining an accelerator-off induction start position Ps from the extended regeneration control start point Pj and the induction period distance Dy.
[0137] Next, the CPU proceeds to step S123 in Fig. 12 and judges whether the current position of the vehicle 10 reaches the accelerator-off induction start position Ps. The CPU repeats the processing of step S123 until the judgment in step S123 becomes affirmative.
[0138] If the judgment in step S123 becomes affirmative, the CPU proceeds to step S124 and starts the accelerator-off induction. Subsequently, the CPU proceeds to step S125 and judges whether the time ts has elapsed since the accelerator-off induction start time. The CPU repeats the processing in step S125 until the judgment in step S125 becomes affirmative.
[0139] When the time ts has elapsed since the accelerator-off induction start time, the CPU judges "Yes" in step S125 and proceeds to step S126, where it judges whether the accelerator pedal 56 is released (whether the accelerator-off is executed). The CPU repeats the processing of step S126 until the judgment in step S126 becomes affirmative.
[0140] If the accelerator pedal 56 has been released or the accelerator pedal 56 is released, the CPU judges "Yes" in step S126 and proceeds to step S127, starting the extended regeneration control. Specifically, the CPU generates a regenerative braking force so that the actual deceleration of the vehicle 10 becomes identical to the ideal deceleration calculated as described above.
[0141] Next, the CPU judges whether the current position of the vehicle 10 reaches the target deceleration end position P0*. The CPU repeats the processing in step S128 until the judgment in step S128 becomes affirmative (positive). Typically, a driver steps on a brake pedal in the middle of the extended regeneration control being executed. As a result, the CPU generates a regenerative braking force equal to the regenerative demand braking force corresponding to the braking operation amount Bp, and generates a friction braking force equal to the demand friction braking force corresponding to the braking operation amount Bp with the friction braking device 65.
[0142] When the current position of the vehicle 10 reaches the target deceleration end position P0*, the CPU judges "Yes" in step S128 and executes processing in step S129 and processing in step S130, which are described below in order, proceeding to step S131 and ending this routine once. After that, the CPU proceeds to step S120.
[0143] Step S129: The CPU terminates the accelerator turn-off induction.
[0144] Step S130: The CPU terminates the extended regeneration control.
[0145] As described above, according to the present control device, in the first case where it is assumed that the electric power amount charged into the accumulator 31 by the extended regeneration control in the slope control section is larger than the first threshold electric power amount (refer to the judgment “Yes” in step S104 in Fig. 10), the target remaining capacity SOC* set in the downhill control section is corrected to a value that is the first adjustment amount ΔS1 smaller than the target remaining capacity SOC* (namely, the low-side remaining capacity Sd = Sn - ΔSd) set when it is assumed that an electric power amount charged into the secondary battery 31 by the extended regeneration control in the downhill control section is smaller than the first threshold electric power amount (including a case where it is predicted that the extended regeneration control in the downhill control section is not executed) (step S106).
[0146] Consequently, since the remaining capacity SOC becomes a sufficiently small value in the pre-use section, even if the extended regeneration control is executed during a period when the vehicle 10 travels through the pre-use section and / or the downhill section (namely, the downhill control section), a possibility that the remaining capacity SOC may reach the remaining capacity upper limit Smax decreases. Consequently, since a situation in which electric power that could have been accumulated in the secondary battery cannot be accumulated does not occur while the vehicle travels through the downhill section, fuel consumption of the vehicle 10 can be further improved.
[0147] Furthermore, according to the present control device, in the second case where it is assumed that the electric power amount charged into the accumulator 31 by the extended regeneration control in the pre-charge section in which the congestion control is executed is larger than the second threshold electric power amount (refer to the judgment “Yes” in step S114 in Fig. 11), the target remaining capacity SOC* set in the pre-charge section is corrected to a value that is the second adjustment amount ΔS2 smaller than the target remaining capacity SOC* (namely, the high-side remaining capacity Sh = Sn + ΔSh) set when the electric power amount charged into the secondary battery 31 by the extended regeneration control in the pre-charge section is assumed to be smaller than the second threshold electric power amount (including a case where the extended regeneration control in the pre-charge control section is predicted not to be executed) (step S116).
[0148] Therefore, even if the extended regeneration control is executed in the pre-charge section, the possibility that the remaining capacity SOC may reach the remaining capacity upper limit Smax decreases. Therefore, since a situation in which electric power that could have been accumulated in the battery cannot be accumulated does not occur, fuel consumption of the vehicle 10 can be further improved.
[0149] Although the present control device is configured to execute both the "slope control and the congestion control" as the look-ahead support control, it may execute either the slope control or the congestion control. In this case, when the present control device executes the slope control and does not execute the congestion control, the CPU executes the Fig. 10 and executes the Fig. 11. On the other hand, when the present control device executes the congestion control and does not execute the slope control, the CPU executes the routine shown in Fig. 11 and executes the Fig. 10 shown routine is not sufficient. <Erste Modifikation des ersten Ausführungsbeispiels>
[0150] Next, a first modification of the embodiment according to the present invention will be explained. The control device for a hybrid vehicle according to the above-described embodiment sets the low-side remaining capacity Sd, which is set as the target remaining capacity SOC*, to the "value that is the predetermined value ΔSd smaller than the standard remaining capacity Sn" when it is predicted that the extended regeneration control will be executed in a period when the vehicle 10 travels the slope control section.
[0151] In contrast, the first modification differs from the above-described embodiment in that the "low-side remaining capacity Sd, which is set as the target remaining capacity SOC* when a predicted value of the electric power amount charged into the secondary battery by the extended regeneration control executed in a period when the vehicle 10 travels the slope control section (hereinafter referred to as a "first predicted regenerated electric power amount") is predicted to be greater than an electric power amount threshold" is set to a "value of a sum of a predetermined value ΔSd and a predetermined value (first adjustment amount) ΔS1a smaller than the standard remaining capacity Sn," and the predetermined value ΔS1a is adjusted according to a magnitude of the first predicted regenerated electric power amount.Specifically, in the first modification, the larger the first predicted regenerated electric power amount is, the larger the above-mentioned predetermined value ΔS1a is set. In other words, in the first modification, the larger the first predicted regenerated electric power amount is, the smaller a value of the target remaining capacity SOC* in the slope control is set in a range where it is larger than the remaining capacity lower limit Smin.
[0152] Further, specifically, the CPU acquires one of the parameters X1 to X5 listed below as an index value X, assuming that the larger the index value X, the larger the first predicted regenerated electric power amount. Then, the CPU sets the above-mentioned predetermined value ΔS1a such that the larger the index value X, the larger the predetermined value ΔS1a. Namely, the CPU sets the low-side remaining capacity Sd such that the larger the index value X, the smaller the low-side remaining capacity Sd. The index value X is a first index value that has a correlation with an electric power amount charged into the secondary battery 31 by the extended regeneration control executed in a period when the vehicle 10 travels on the slope control section (the larger the electric power amount, the larger the first index value).
[0153] (A1) The number X1 of the extended regeneration control expected to be executed in the slope control section. Namely, the number X1 of the target deceleration end position P0* in the slope control section, which is registered in the non-volatile memory.
[0154] (A2) A total distance X2 of a “combined distance of the extended regeneration distance De and the target braking distance Db*” corresponding to each extended regeneration control expected to be executed in the slope control section.
[0155] (A3) The number X3 of the expected regeneration control in which a difference between the current vehicle speed of the vehicle 10 and the target deceleration end vehicle speed V0* registered in the non-volatile memory exceeds a threshold value Vth in the slope control section. The threshold value Vth is determined based on the minimum value of a "difference between a vehicle speed and a target deceleration end vehicle speed" at which a regenerated electric power amount becomes a predetermined amount or more in the vehicle 10.
[0156] (A4) A value X4 (= a / b) obtained by dividing an average value a of the number of extended regeneration control executed in one trip after an ignition key switch of the vehicle 10 (or a power switch of a hybrid vehicle) is turned on until it is turned off by an average value b of a travel distance of the vehicle 10 in one trip.
[0157] (A5) A value X5 (= c / b) obtained by dividing an average value c of total distances of the “combined distance of the extended regeneration distance De and the target braking distance Db*” corresponding to each extended regeneration control executed in one trip by an average value b of a travel distance of the vehicle 10 in one trip.
[0158] The values X4 and X5 represent a driver's operating characteristic (a tendency to repeat a braking operation). (Specific operation)
[0159] The CPU in the first modification repeatedly executes a routine defined by a flowchart in Fig. 14, instead of Fig. 10 at a predetermined time interval. Among the steps described in Fig. 14, the same reference numerals as those shown in Fig. 10 are given the steps for carrying out processing identical to the processing carried out in the steps described in Fig. 10, with a corresponding explanation being omitted.
[0160] If the CPU in step S102 according to Fig. 14 judges "Yes" and proceeds to step S142, it is judged whether the index value X (one of the above-mentioned index values X1 to X5) is not less than the threshold value Xth. If the index value X is not less than the threshold value Xth, it can be assumed that the electric power amount charged into the battery 31 by the extended regeneration control in the slope control section is greater than the first threshold electric power amount.
[0161] If the index value X is smaller than the threshold value Xth, the CPU judges "No" in step S142 and proceeds to step S105, where it sets the low-side remaining capacity Sd to a "value obtained by subtracting a certain value ΔSd (for example, 5% of the maximum charge of the battery 31) from the standard remaining capacity Sn." In this case, the first adjustment amount ΔS1a can be said to be "zero."
[0162] On the other hand, if the index value X is not smaller than the threshold value Xth, the CPU judges "Yes" in step S142 and proceeds to step S143, where it calculates the first adjustment amount ΔS1a (= f(X)) by substituting the index value X for a function f. The function f is a monotonically increasing function, where the larger the index value X, the larger the value f(X). Therefore, the larger the index value X, the larger the first adjustment amount ΔS1a becomes.
[0163] Next, the CPU proceeds to step S144 and sets the low-side remaining capacity Sd to a "value (= (Sn - ΔSd) - ΔS1a) obtained by subtracting the first adjustment amount ΔS1a from a value (Sn - ΔSd) obtained by subtracting a certain value ΔSd from the standard remaining capacity Sn." As a result, the larger a predicted value of an electric power amount charged into the secondary battery 31 by the extended regeneration control having the index value X of not less than the threshold value Xth and executed in a period when the vehicle 10 travels the downhill control section (namely, the first predicted regenerated electric power amount), the larger the first adjustment amount ΔS1a becomes, and the smaller the target remaining capacity SOC* set in the downhill control becomes.
[0164] Therefore, according to the first modification, the possibility that the remaining capacity SOC may reach the remaining capacity upper limit Smax by the extended regeneration control during the period when the vehicle 10 travels on the slope control section can be further reduced. Consequently, the possibility of a situation in which electric energy that could have been stored in the battery cannot be stored can be reduced. <Zweite Modifikation des Ausführungsbeispiels>
[0165] Next, a second modification of the embodiment of the present invention will be explained. The control device for a hybrid vehicle according to the above-described embodiment sets the high-side remaining capacity Sa, which is set as the target remaining capacity SOC*, to the "value that is the predetermined value ΔSa greater than the standard remaining capacity Sn" when it is predicted that the extended regeneration control will be executed in a period when the vehicle 10 travels the pre-charging section before the congestion section.
[0166] In contrast, the second modification differs from the above-mentioned embodiment in that the “high-side remaining capacity Sh, which is set as the target remaining capacity SOC* when a predicted value of the electric power amount charged into the secondary battery by the extended regeneration control executed in a period when the vehicle 10 travels the pre-charging section (hereinafter referred to as a “second predicted regenerated electric power amount”) is predicted to be larger than an electric power amount threshold value” to a “value obtained by subtracting a predetermined value (second adjustment amount) ΔS2a from a value obtainedby adding a predetermined value ΔS2a to the standard remaining capacity Sn" and adjusting the predetermined value ΔS2a according to a magnitude of the second predicted regenerated electric power amount. More specifically, in the second modification, the larger the second predicted regenerated electric power amount, the larger the above-mentioned predetermined value ΔS2a is set. In other words, in the second modification, the larger the second predicted regenerated electric power amount, the smaller a value to which the target remaining capacity SOC* is set in the slope control in a range where it is larger than the standard remaining capacity Sn.
[0167] Further, the CPU specifically acquires one of the parameters listed below as an index value Y, assuming that the larger the index value Y, the larger the second predicted regenerated electric power amount. Then, the CPU sets the above-mentioned predetermined value ΔS2a such that the larger the index value Y, the larger the predetermined value ΔS2a. Namely, the CPU sets the high-side remaining capacity Sh such that the larger the index value Y, the smaller the high-side remaining capacity Sh. The index value Y is the second index value that has a correlation with an electric power amount charged into the secondary battery 31 by the extended regeneration control executed in a period when the vehicle 10 travels the pre-charge section (the larger the electric power amount, the larger the second index value).
[0168] (B1) The number Y1 of the extended regeneration control expected to be executed in the precharge section. In other words, the number Y1 of the target deceleration end position P0* in the precharge section, which is registered in the non-volatile memory.
[0169] (B2) A total distance Y2 of a “combined distance of the extended regeneration distance De and the target braking distance Db*” corresponding to each of the extended regeneration controls expected to be executed in the pre-charge section.
[0170] (B3) The number Y3 of extended regeneration control in which a difference between the current vehicle speed of the vehicle 10 and the target deceleration end vehicle speed V0* registered in the non-volatile memory exceeds a threshold value Vth in the pre-charge section. The threshold value Vth is determined based on the minimum value of a "difference between a vehicle speed and a target deceleration end vehicle speed" at which a regenerated electric power amount becomes a predetermined amount or more in the vehicle 10.
[0171] (B4) A value Y4 that is identical to the value X4.
[0172] (B5) A value Y5 that is identical to the value X5. (Specific operation)
[0173] The CPU in the second modification repeatedly executes a routine represented by a flowchart in Fig. 15, instead of Fig. 11 at a predetermined time interval. Among the steps described in Fig. 15, the same reference numerals as those shown in Fig. 11 the steps for carrying out the processing which is identical to the processing carried out in the steps described in Fig. 11, a description thereof being omitted.
[0174] If the CPU in step S112 according to Fig. 15 judges "Yes" and proceeds to step S152, it judges whether the index value Y (one of the above-mentioned index values Y1 to Y5) is not less than the threshold value Yth. If the index value Y is not less than the threshold value Yth, it can be assumed that the electric power amount charged into the secondary battery 31 by the extended regeneration control in the precharge section is greater than the second threshold electric power amount.
[0175] If the index value Y is less than the threshold value Yth, the CPU judges "No" in step S152 and proceeds to step S115, where it sets the high-side remaining capacity Sh to a "value obtained by adding a certain value ΔSh (for example, 5% of the maximum charge of the battery 31) to the standard remaining capacity Sn." In this case, the second adjustment amount ΔS2a can be said to be "zero."
[0176] On the other hand, if the index value Y is not smaller than the threshold value Yth, the CPU judges "Yes" in step S125 and proceeds to step S153, where it calculates the second adjustment amount ΔS2a (= g(Y)) by substituting the index value Y for a function g. The function g is a monotonically increasing function, where the larger the index value Y, the larger the value g(Y). Therefore, the larger the index value Y, the larger the second adjustment amount ΔS2a becomes. However, when the second adjustment amount ΔS2a becomes the specified value ΔSh or more corresponding to the function g, the CPU sets the second adjustment amount ΔS2a to the specified value ΔS2a.
[0177] Next, the CPU proceeds to step S154, where it sets the high-side remaining capacity Sh to a “value (= Sn + ΔSh) - ΔS2a) obtained by subtracting the second adjustment amount ΔS2a from a value (Sn + ΔSh) obtained by adding the determined value ΔSh to the standard remaining capacity Sn.” As a result, the larger the predicted value of an electric power amount charged into the secondary battery 31 by the extended regeneration control having the index value Y not smaller than the threshold value Yth and executed in a period when the vehicle 10 travels the pre-charging section (namely, the second predicted regenerated electric power amount), the larger the second adjustment amount ΔS2a becomes, and the smaller the target remaining capacity SOC* set in the pre-charging section becomes in a range where it is larger than the standard remaining capacity Sn.
[0178] Therefore, according to the second modification, the possibility that the remaining capacity SOC may reach the remaining capacity upper limit Smax by the extended regeneration control during the period when the vehicle 10 travels in the pre-charging section can be further reduced. Consequently, useless operation of the internal combustion engine 23 in the pre-charging section can be eliminated, and the possibility of a situation where electric energy that could be stored in the secondary battery cannot be stored can be reduced.
[0179] The present invention is not limited to the above-mentioned embodiments, and various modifications can be applied within the scope of the present invention. For example, the present invention can also be implemented according to a modification that is a combination of the first modification and the second modification.
[0180] Furthermore, in the first modification, the first adjustment amount ΔS1a may be changed based on two or more index values in the above-mentioned values X1 to X5. For example, when X1 and X2 are used as the index value X, the first adjustment amount ΔS1a may be determined such that the larger the index value X1 is, the larger the first adjustment amount ΔS1a becomes, and such that the larger the index value X2 is, the larger the first adjustment amount ΔS1a becomes, as shown in Fig. 16 is shown.
[0181] Similarly, in the second modification, the second adjustment amount ΔS2a may be changed based on two or more index values in the above-mentioned values Y1 to Y5. For example, when Y1 and Y2 are used as the index value Y, the second adjustment amount ΔS2a may be determined such that the larger the index value Y1 is, the larger the second adjustment amount ΔS2a becomes, and such that the larger the index value Y2 is, the larger the second adjustment amount ΔS2a becomes, as shown in Fig. 16 is shown. List of reference symbols
[0182] 10: vehicle or hybrid vehicle, 21: first motor, 22: second motor, 23: internal combustion engine, 24: power split mechanism, 25: axle, 26: differential gear, 27: drive wheels, 31: accumulator, 32: boost converter, 33: first inverter, 34: second inverter, 40: ECU, 51: crank angle sensor, 52: ammeter, 53: vehicle speed sensor, 54: accelerator opening sensor, 55: brake opening sensor, 61: GPS receiving device, 62: traffic information receiving device, 63: database, 64: display device, 65: friction brake device.
[0183] When judging that a downhill section exists in a planned travel route, the control device of a hybrid vehicle sets a target remaining capacity SOC* in a pre-use section, a downhill section, and the downhill section to a "low-side remaining capacity Sd that is ΔSd smaller than the standard remaining capacity Sn" (step S105). Furthermore, when assuming that an increase amount of a remaining capacity by extended regeneration control is large in the pre-use section and the downhill section (refer to a "Yes" judgment in step S104), the target remaining capacity SOC* is set to a "low-side remaining capacity Sd that is a sum of ΔSd and ΔS1 smaller than the standard remaining capacity Sn" (step S106).
Claims
[1] A control device for a hybrid vehicle (10) applied to the hybrid vehicle (10) comprising an internal combustion engine (23) as a drive source of a hybrid vehicle (10) and motors (21, 22) as drive sources, and an accumulator (31) that supplies electric power to the motors (21, 22), wherein it is configured to be capable of performing regenerative braking using the motors (21, 22) and charging the accumulator (31) with electric power generated by the regenerative braking, and is configured to be capable of charging the accumulator (31) with electric power generated using an output of the internal combustion engine (23), and the control device for a hybrid vehicle (10) comprises a control part (40) configured to control the internal combustion engine (23) and the motors (21, 22) such that a demand driving force required for the hybrid vehicle (10) is satisfied, and to control such that a remaining capacity (SOC) of the accumulator (31) approaches a target remaining capacity (SOC*) set to a standard remaining capacity (Sn), which is the target remaining capacity (SOC*) at a normal time, wherein the control part (40) comprises: a traffic information receiving device (62) configured to obtain information about a planned route of the hybrid vehicle (10) and a location of the hybrid vehicle (10), an assistance control device (40) configured to execute, as a look-ahead assistance control, at least one control from: a downhill control in which the target remaining capacity (SOC*) is changed to a low-side remaining capacity (Sd) that is smaller than the standard remaining capacity (Sn) while the hybrid vehicle (10) is traveling on a section that includes at least one pre-use section within a first section, when it is judged, based on information about the planned travel route, that a planned travel route of the hybrid vehicle (10) includes a downhill section that satisfies a predetermined downhill section condition, wherein the pre-use section is a section from a start point of the downhill control to a start point of the downhill section, the first section is a section from the start point of the downhill control to an end point of the downhill section, and the start point of the downhill control is a predetermined first distance before the start point of the downhill section, and a congestion control in which the target remaining capacity (SOC*) is changed to a high-side remaining capacity (Sh) that is greater than the standard remaining capacity (Sn) while the hybrid vehicle (10) is traveling a second section when it is judged, based on information about the planned travel route, that the planned travel route of the hybrid vehicle (10) includes a congestion section that satisfies a predetermined congestion section condition, wherein the second section is a section from a start point of the congestion control to a start point of the congestion section, and the start point of the congestion control is a predetermined second distance before the start point of the congestion section, and an extended regeneration control device is configured to execute extended regeneration control, wherein the extended regeneration control is a control in which a location at which deceleration of the hybrid vehicle (10) is predicted to end based on everyday driving by a driver of the hybrid vehicle (10) is set as a target deceleration end location, a deceleration start location is set, and regenerative braking is intensified from the deceleration start location, so that an amount of electric power charged into the accumulator (31) by regenerative braking from the deceleration start location to the target deceleration end location becomes larger compared to an amount of electric power charged into the accumulator (31) by everyday driving by the driver when predicted based on information about a location of the hybrid vehicle (10),that the hybrid vehicle (10) slows down, whereby:, the control part (40) comprises a target residual capacity correction device (40) which is configured correct the target remaining capacity (SOC*) to a value that is a first adjustment amount (ΔS1, ΔS1a) smaller than the low-side remaining capacity (Sd) in a first case, which is a case in which an electric power amount charged into the accumulator (31) by the extended regeneration control when the hybrid vehicle (10) travels the first section including the section in which the slope control is executed is greater than a first threshold electric power amount, and correct the target remaining capacity (SOC*) to a value that is a second adjustment amount (ΔS2, ΔS2a) smaller than the high-side remaining capacity (Sh) in a second case, which is a case where an electric power amount charged into the accumulator (31) by the extended regeneration control when the hybrid vehicle (10) travels the second section including the section in which the congestion control is executed is larger than a second threshold electric power amount. [2] Control device according to claim 1, wherein the target residual capacity correction device (40) is configured such that the first adjustment amount (ΔS1, ΔS1a) increases as a first index value (X) increases, which has a correlation with an amount of electric power charged into the accumulator (31) by an execution of the extended regeneration control in a period when the hybrid vehicle (10) travels the first section in the first case, and that the second adjustment amount (ΔS2, ΔS2a) increases as a second index value (Y) increases which has a correlation with an electric power amount charged into the accumulator (31) by an execution of the extended regeneration control in a period when the hybrid vehicle (10) travels the second section in the second case.
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