JP5939197B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to the technical field of hybrid vehicle control devices.

  Some hybrid vehicles including an internal combustion engine and a rotating electric machine as a power source can run only with power supplied from the rotating electric machine with the internal combustion engine stopped. As a reference to the starting conditions of the internal combustion engine during the engine stop running, there is Patent Document 1. Patent Document 1 discloses a configuration for displaying the current traveling power and engine starting power in order to notify the driver of the starting timing.

  Further, there is Patent Document 2 as a reference to the starting condition of the internal combustion engine while the engine is stopped. Patent Document 2 discloses a configuration in which a state quantity related to the propulsive force of the vehicle and a threshold value of the state quantity that requires starting of the internal combustion engine are calculated based on the running power and running torque of the hybrid vehicle. Further, Patent Document 2 includes a dead zone so that the display of the traveling power does not change due to the influence of creep torque in a low speed region in a CD (Charge Depleting) mode (that is, a traveling mode in which electric power traveling by external charging power is performed). The provided configuration is also disclosed.

  Patent Document 3 discloses a configuration that indicates to the driver the accelerator opening at which switching between EV (Electric Vehicle) mode (CD mode in terms of the above) and HV (Hybrid Vehicle) mode occurs. Has been.

WO2011 / 030444 gazette JP 2011-157115 A JP 2008-074321 A

  In recent years, with the expansion of charging infrastructure facilities and the improvement of battery performance, the travel area in the CD mode has been increasing in PHVs (Plug-in Hybrid Vehicles) that can be charged from an external power source.

  The expansion of the traveling area of the CD mode is economical because low-cost electric power supplied from the outside can be used, but on the other hand, the internal combustion engine other than that caused by the conventional output requirement is started. Specifically, when the traveling area of the CD mode is expanded, the frequency of occurrence of the internal combustion engine start request (start request based on the drive force requirement) due to insufficient drive force increases.

  For this reason, as disclosed in Patent Document 1, when only the start timing of the internal combustion engine according to the output requirement (power, that is, output) is notified, the internal combustion engine at an unexpected timing by the driver. May start.

  The driving force corresponds one-to-one with the driving torque if the physical configuration of the driving force transmission path does not change. Therefore, the start request based on the driving force requirement means another start request based on the torque requirement.

  For such a problem, according to the configuration of Patent Document 2, both information related to the start timing based on the output requirement and information related to the start timing based on the driving force (travel torque in the document) requirement are displayed. At first glance it is meaningful.

  By the way, in Patent Document 2, a first calculation value indicating a ratio of an actual output value to a start threshold value according to an output requirement (output value for which start is required) and a start threshold value based on a driving force requirement (start is required). A configuration is also disclosed in which a second calculated value indicating the ratio of the actual driving force value to the driving force (running torque value in the literature) is calculated, and the larger one of these values is displayed.

  However, from the viewpoint of the driver, it is not desirable that the information display based on the output requirement and the information display based on the driving force requirement are switched irregularly. In particular, for a general driver, the difference between the output and the driving force (driving torque) is not clear, and such measures may cause confusion for the driver.

  Here, in view of the fact that the driving force or the driving torque can be easily converted into an output by considering the vehicle speed, it is meaningful to convert the starting threshold value based on the driving force requirement into the starting threshold value based on the output requirement. In this case, the current output value may be compared with both the start threshold value of the output requirement and the start threshold value of the driving force requirement, and the larger of these ratios (that is, the current output) in consideration of the configuration of Patent Document 2. If the value of the value closer to the starting threshold value is displayed, it is visually clear.

  However, since the output value converted from the driving force naturally increases as the vehicle speed increases, for example, in the process of increasing the vehicle speed while maintaining the accelerator opening constant, the starting threshold value of the driving force requirement Gradually shifts to the high output side.

  For this reason, when trying to notify the start timing based on the ratio of the current output value to the start threshold value, the ratio decreases relatively with the shift of the start threshold value to the high output side, the accelerator opening is constant, and the vehicle speed is constant. This results in giving the driver the impression that the starting timing is moving away from the actual situation that is rising.

  Therefore, the display content of the information related to the start timing is not consistent with the driver's feeling, which causes the driver to feel uncomfortable or uncomfortable. That is, in the category of conventional technical ideas including those disclosed in the above-mentioned patent documents, it is possible to sufficiently suppress discomfort and discomfort given to the driver when notifying the start timing of the internal combustion engine during the CD mode traveling. Can not.

  The present invention has been made in view of such problems, and provides a hybrid vehicle control device capable of notifying a driver of information related to the start timing of an internal combustion engine without causing discomfort or discomfort in a hybrid vehicle. This is the issue.

  In order to solve the above-described problems, a hybrid vehicle control device according to the present invention is a hybrid vehicle control device that controls a hybrid vehicle including display means, an internal combustion engine, and at least one rotating electrical machine, A first required output value of the hybrid vehicle that requires starting of the internal combustion engine due to a lack of torque of the rotating electrical machine during a period in which the hybrid vehicle travels using only the rotating electrical machine as a power source is calculated. The first calculation means, the second calculation means for calculating the current output value of the hybrid vehicle, and the ratio between the calculated first required output value and the calculated current output value are displayed. Display control means for controlling the display means, and suppression means for suppressing changes in the displayed ratio based on vehicle speed and accelerator opening. It characterized the door (claim 1).

  According to the hybrid vehicle control apparatus of the present invention, the first calculation means calculates the first required output value that requires the internal combustion engine to start due to insufficient torque of the rotating electrical machine. The insufficient torque of the rotating electrical machine means that the driving force acting on the driving wheel is unsatisfactory in view of the correlation between the torque and the driving force. That is, the first required output value is an output value at which a request for starting the internal combustion engine based on the driving force requirement is generated.

  The display means that can take the form of an indicator or the like installed in the passenger compartment displays the ratio between the first required output value and the current output value of the hybrid vehicle. This ratio includes the meaning of the ratio of the current output value to the first required output value.

  In addition, the display mode of the ratio is arbitrary, and may be a numerical value or a graph, for example. In addition, any visual effect may be given when the ratio is displayed. In addition to the ratio, other information may be displayed.

  Here, since the first required output value is a start required output value based on the driving force requirement, it changes according to the vehicle speed.

  Therefore, if the degree of increase in the current output value in the process of increasing the vehicle speed is smaller than the degree of increase in the first required output value in the process of increasing vehicle speed, the accelerator opening is constant. Even so, the ratio decreases as the vehicle speed increases. Such a phenomenon occurs particularly remarkably in a medium vehicle speed region (for example, a vehicle speed region of about 30 to 70 km / h), a middle accelerator opening region (for example, an accelerator opening region of about 20 to 60%), and the like.

  Conversely, if the degree of increase in the current output value in the process of increasing the vehicle speed is greater than the degree of increase in the first required output value in the process of increasing vehicle speed, the accelerator opening is constant. However, the ratio increases as the vehicle speed increases. Such a phenomenon occurs remarkably particularly in the region of low vehicle speed and low accelerator opening (for example, when slowly accelerating from creep running). Such a change in the ratio deviates from the driver's feeling, and does not necessarily notify the driver of the accurate start timing of the internal combustion engine.

  Therefore, in the hybrid vehicle control device according to the present invention, the suppression means suppresses the change in the ratio based on the vehicle speed and the accelerator opening. Therefore, according to the control apparatus for a hybrid vehicle according to the present invention, the change in the ratio that deviates from the driver's feeling is suppressed, and the uncomfortable feeling or discomfort given to the driver can be suppressed.

  In addition, about the concrete suppression aspect which concerns on a suppression means, numerically defining and defining a vehicle speed and an accelerator opening degree reduces the essential technical idea of this invention. That is, the present invention has been made by newly finding out that the start required output value of the driving force requirement cannot sufficiently serve as a threshold value depending on the traveling condition of the hybrid vehicle defined by the accelerator opening and the vehicle speed. And has an inventive step to suppress the change in the displayed ratio.

  However, if a preferred embodiment is described from a qualitative viewpoint, for example, when the accelerator opening is constant or increases and the vehicle speed increases, the suppression means is in the middle vehicle speed region and the middle accelerator opening region. The change to the decreasing side of the ratio is suppressed. This is because the change to the increase side of the ratio means that the current output approaches the start request output accompanying an increase in the required drive force, and it may be considered that there is no need to suppress it.

  In one aspect of the hybrid vehicle control device according to the present invention, the first calculation means is configured such that the output of the rotating electrical machine is insufficient during a period in which the hybrid vehicle travels using only the rotating electrical machine as a power source. Further calculating a second required output value of the hybrid vehicle that requires starting of the internal combustion engine, and the display control means is the smaller one of the calculated first required output value and second required output value. The display means is controlled so that a ratio between the calculated value and the calculated current output value is displayed, and the suppressing means controls the calculated first requested output value and the calculated current value. When the ratio with the output value is displayed, the change of the displayed ratio is suppressed (Claim 2).

  According to this aspect, the second required output value that is required to start the internal combustion engine due to the insufficient output of the rotating electrical machine is calculated, and is smaller between the first required output value and the second required output value. This value is applied to calculate the ratio. In other words, the larger value of the ratio based on the driving force requirement and the ratio based on the output requirement is displayed. Therefore, the driver can grasp the start timing of the internal combustion engine more accurately.

  In addition, unlike the first required output value, the second required output value is a value determined by the output requirement, so that it is not affected by the driving conditions of the vehicle except for the SOC of the battery and the charge / discharge limit value. . Therefore, the ratio to which the second required output value is applied does not show a behavior deviating from the driver's feeling. That is, for the period in which the ratio to which the second required output value is applied is displayed, no measure for suppressing the change in the ratio relating to the suppressing means is required. According to this aspect, only the ratio to which the first required output value is applied is taken for measures for suppressing the change in the ratio, so that it is efficient and accurate.

  In another aspect of the control device for a hybrid vehicle according to the present invention, the suppression means may display the displayed ratio when the travel region of the hybrid vehicle determined by the vehicle speed and the accelerator opening corresponds to a predetermined region. (Claim 3).

  According to this aspect, when the traveling region determined by the accelerator opening and the vehicle speed corresponds to the predetermined region, the displayed ratio is maintained. Therefore, it is possible to enjoy the practical benefits of the present invention in a relatively simple manner.

  In another aspect of the hybrid vehicle control device according to the present invention, the suppression means suppresses a decrease in the ratio when the accelerator opening is constant or increasing and the vehicle speed is increasing. (Claim 4).

  The ratio based on the driving force requirement shows an unnatural decrease in change when the vehicle speed is increased and the first start request output value is increased, and the current output value is the conventional value. This is a case where the accelerator opening is constant or increased without greatly changing from the value of.

  According to this aspect, a decrease in the ratio is suppressed when the accelerator opening is constant or increasing and when the vehicle speed is increasing. Therefore, the uncomfortable feeling or discomfort given to the driver can be efficiently and effectively suppressed.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

1 is a schematic configuration diagram conceptually illustrating a configuration of a hybrid vehicle according to a first embodiment of the present invention. It is a schematic block diagram of the hybrid drive device in the hybrid vehicle of FIG. It is a figure which illustrates the display contents of the indicator in the hybrid vehicle of FIG. It is a flowchart of the indicator control process performed in the hybrid vehicle of FIG. It is a figure explaining the concept of the hysteresis value in the indicator control process of FIG. It is a flowchart of the indicator control process which concerns on 2nd Embodiment of this invention. It is a figure explaining the concept of the reflection coefficient in the indicator control process of FIG.

<Embodiment of the Invention>
Hereinafter, various embodiments of the present invention will be described with reference to the drawings.

<Configuration of Embodiment>
First, the configuration of the hybrid vehicle 1 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the hybrid vehicle 1.

  In FIG. 1, a hybrid vehicle 1 includes an ECU (Electronic Control Unit) 100, a hybrid drive device 10, a PCU (Power Control Unit) 20, a battery 30, an indicator 40, a sensor group 50, a switching device 60, and a plug 61. Is an example of a “hybrid vehicle” according to the present invention.

  The ECU 100 is an electronic control unit that includes a CPU, a ROM, a RAM, and the like, and is configured to be able to control the operation of each part of the hybrid vehicle 1, and is an example of the “hybrid vehicle control device” according to the present invention. The ECU 100 can execute an “indicator control process” to be described later according to a control program stored in the ROM.

  The PCU 20 converts DC power extracted from the battery 30 into AC power and supplies it to a motor generator MG1 and a motor generator MG2, which will be described later, and converts AC power generated by the motor generator MG1 and the motor generator MG2 into DC power. Inverter 22 (not shown) configured to be able to be supplied to battery 30, the power input / output between battery 30 and each motor generator, or the power input / output between each motor generator (that is, in this case) The control unit is configured to be capable of controlling power transfer between the motor generators without using the battery 30. The PCU 20 is electrically connected to the ECU 100 and its operation is controlled by the ECU 100.

  The battery 30 is a rechargeable secondary battery unit that functions as a power supply source related to power for powering the motor generator MG1 and the motor generator MG2. The battery 30 has a configuration in which a plurality (for example, several hundreds) of unit battery cells such as lithium ion battery cells are connected in series.

  The indicator 40 is an example of the “display unit” according to the present invention including a display unit (not shown) installed near the driver's seat of the hybrid vehicle 1 (for example, in a console panel or a meter hood). The display unit of the indicator 40 is configured to display engine start timing information in an indicator control process described later. The indicator 40 is electrically connected to the ECU 100, and the display content of the display unit on the indicator 40 is controlled by the ECU 100.

  The sensor group 50 is a collective name for various sensors that detect the state of the hybrid vehicle 1. The sensor group 50 includes at least a battery temperature sensor 51, an accelerator opening sensor 52, an SOC sensor 53, and a vehicle speed sensor 54.

  The battery temperature sensor 51 is a sensor that detects a battery temperature Tbat that is the temperature of the battery 30. The battery temperature sensor 51 is electrically connected to the ECU 100, and the detected battery temperature Tbat is appropriately referred to by the ECU 100.

  The accelerator opening sensor 52 is a sensor that detects an accelerator opening Ta that is an opening of an accelerator pedal. The accelerator opening sensor 52 is electrically connected to the ECU 100, and the detected accelerator opening Ta is appropriately referred to by the ECU 100.

  The SOC sensor 53 is a sensor that detects the SOC that is the remaining charge capacity of the battery 30. The SOC sensor 53 is electrically connected to the ECU 100, and the detected SOC is appropriately referred to by the ECU 100.

  The vehicle speed sensor 54 is a sensor that detects the vehicle speed V of the hybrid vehicle 1. The vehicle speed sensor 54 is electrically connected to the ECU 100, and the detected vehicle speed V is appropriately referred to by the ECU 100.

  The switching device 60 is a switching device for switching the charging mode of the battery 30 between external charging and internal charging. A charging plug 61 is connected to the switching device 60. The charging plug 61 is a plug for receiving power supply from an external power supply source such as a charging stand as infrastructure equipment or a household power source. When the charging plug 61 is inserted into the insertion port, the switching state of the switching device 60 is switched to the external charging side. The switching device 60 is electrically connected to the ECU 100, and the switching state of the switching device 60 is controlled by the ECU 100. The hybrid vehicle 1 can receive power supply from the external power source as described above, and constitutes an example of a so-called plug-in hybrid vehicle.

  The hybrid drive device 10 is a power train of the hybrid vehicle 1. Here, the detailed configuration of the hybrid drive apparatus 10 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram conceptually showing the configuration of the hybrid drive apparatus 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  The hybrid drive device 10 includes an engine 200, a power split mechanism 300, an input shaft 400, a drive shaft 500, a speed reduction mechanism 600, a motor generator MG1 (hereinafter referred to as “MG1” where appropriate), a motor generator MG2 (hereinafter referred to as “MG2” as appropriate). For short).

  The engine 200 is a gasoline engine that functions as a main power source of the hybrid vehicle 1 and is an example of the “internal combustion engine” according to the present invention.

  The engine 200 includes a piston that reciprocates inside the cylinder in response to an explosive force generated when the air-fuel mixture burns in a combustion chamber formed inside the cylinder. The reciprocating motion of the piston is converted into the rotational motion of the crankshaft via the connecting rod, and is taken out from the input shaft 400 connected to the crankshaft. Note that the detailed configuration of the engine 200 is omitted here because it has a low relationship with the present invention. Although the engine 200 is a gasoline engine here, there are a wide variety of practical aspects that can be taken by the “internal combustion engine” according to the present invention. For example, the “internal combustion engine” according to the present invention is free in fuel type, cylinder arrangement, number of cylinders, fuel supply mode, valve system configuration, intake / exhaust system configuration, and the like.

  Motor generator MG1 is a motor generator having a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy.

  Motor generator MG2 is a motor generator having a larger physique than motor generator MG1, and, like motor generator MG1, has a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy. 1 is an example of a “rotary electric machine” according to the present invention.

  The motor generators MG1 and MG2 are configured as synchronous motor generators and include, for example, a rotor having a plurality of permanent magnets on the outer peripheral surface and a stator wound with a three-phase coil that forms a rotating magnetic field. You may have the structure of.

  The power split mechanism 300 is a known planetary gear mechanism that includes a plurality of rotating elements that have a differential action with respect to each other.

  The power split mechanism 300 is disposed between the sun gear S1 provided at the center, the ring gear R1 provided concentrically on the outer periphery of the sun gear S1, and the sun gear S1 and the ring gear R1. A plurality of pinion gears (not shown) that revolve while rotating, and a carrier C1 that supports the rotation shaft of each pinion gear.

  Sun gear S1 is a reaction force element for bearing reaction torque against engine torque Te, which is output torque of engine 200, and is fixed to an output rotation shaft to which the rotor of motor generator MG1 is fixed. Therefore, the rotational speed of sun gear S1 is equivalent to MG1 rotational speed Nmg1, which is the rotational speed of motor generator MG1.

  The ring gear R1 is an output element of the power split mechanism 300, and is connected to a drive shaft 500, which is a power output shaft of the power split mechanism 300, in a manner sharing its rotational axis. The drive shaft 500 is indirectly connected to the drive wheels DW of the hybrid vehicle 1 through a differential or the like.

  The carrier C1 is connected to the input shaft 400 connected to the crankshaft of the engine 200 via the torsion damper TDP so as to share the rotation shaft, and the rotation speed is equal to the engine speed NE of the engine 200. Is equivalent.

  In the power split mechanism 300, the engine torque Te supplied from the engine 200 to the input shaft 400 is transferred to the sun gear S1 and the ring gear R1 by the carrier C1 with the predetermined ratio (the gear ratio between the gears). It is possible to divide the power of the engine 200 into two systems.

  At this time, in order to make the operation of the power split mechanism 300 easy to understand, when the gear ratio ρ as the number of teeth of the sun gear S1 with respect to the number of teeth of the ring gear R1 is defined, the engine torque Te is applied from the engine 200 to the carrier C1. In this case, the torque Tes acting on the sun gear S1 is expressed by the following equation (1), and the direct torque Tep appearing on the drive shaft 500 is expressed by the following equation (2).

Tes = −Te × ρ / (1 + ρ) (1)
Tep = Te × 1 / (1 + ρ) (2)
Deceleration mechanism 600 is a planetary gear mechanism that includes rotation elements of sun gear S2, ring gear R2, pinion gear (not shown), and carrier C2 interposed between drive shaft 500 and motor generator MG2.

  In reduction mechanism 600, sun gear S2 is fixed to an output rotation shaft fixed to the rotor of motor generator MG2. The carrier C2 is fixed to the outer case of the hybrid drive device 10 so as not to rotate. Further, the ring gear R <b> 2 is connected to the drive shaft 500. In such a configuration, reduction mechanism 600 transmits MG2 rotation speed Nmg2, which is the rotation speed of motor generator MG2, to drive shaft 500 while reducing the speed according to the reduction ratio determined according to the gear ratio of each rotation element (gear). I can do it. In the hybrid drive device 10, the MG2 rotational speed Nmg2 is uniquely related to the vehicle speed V.

  It should be noted that the configuration of speed reduction mechanism 600 is merely one form that can be adopted by a mechanism that decelerates the rotation of motor generator MG2, and this type of speed reduction mechanism can have various forms in practice. Further, this type of reduction mechanism is not necessarily provided in the hybrid drive device. That is, motor generator MG2 may be directly connected to drive shaft 500.

<Operation of Embodiment>
Next, the operation of this embodiment will be described.

<Driving mode of hybrid vehicle 1>
The hybrid vehicle 1 has a CS (Charge Sustaining) mode and a CD (Charge Depleting) mode as travel modes that define the power transmission mode between the hybrid drive device 10 and the drive wheels DW.

  The CS mode (also referred to as HV (Hybrid Vehicle) mode or the like) uses the power split action of the power split mechanism 300 to generate a direct torque Ter that is a part of the engine torque Te and an output torque of the motor generator MG2. In this mode, a certain MG2 torque Tmg2 is cooperatively applied to the drive shaft 500. In the CS mode, electric power regeneration, that is, power generation is also performed by MG1 torque Tmg1, which is an output torque of motor generator MG1, using reaction force torque Tes which is another part of engine torque Te.

  At this time, the operating point of the engine 200 (the operating condition defined by the engine speed NE and the engine torque Te) is an electric CVT (Continuously Variable Transmission) of the hybrid drive device 10 using the MG1 torque Tmg1 as a reaction torque. It can be set freely depending on the function. The operating point of the engine 200 is controlled to an optimum fuel efficiency operating point at which the fuel consumption rate (fuel efficiency) of the engine 200 is minimized as a preferred embodiment.

  On the other hand, MG2 torque Tmg2 is basically controlled to compensate for the shortage of direct torque Tep with respect to drive shaft required torque Tpn required for drive shaft 500. That is, in the CS mode, cooperative control between the MG2 torque Tmg2 and the engine torque Te is performed.

  For example, in this cooperative control, the power generation amount of motor generator MG1 and the discharge amount of motor generator MG2 or further the discharge amount of the auxiliary device are set so that the SOC of battery 30 is maintained at the target SOC as the target value. Constantly adjusted. For example, if the SOC of the battery 30 is higher than the target SOC, the ratio of the MG2 torque Tmg2 to the drive shaft required torque is increased, or the discharge limit value of the battery 30 is increased, so that the power balance is inclined toward the discharge side. On the contrary, if the ratio is lower than the target SOC, the ratio is decreased, or the charge request value of the battery 30 is increased, and the power balance is inclined toward the charging side.

  In contrast, the CD mode (also referred to as EV (Electric Vehicle) mode) is a mode in which only the MG2 torque Tmg2 is applied to the drive shaft 500 and the hybrid vehicle 1 is driven only by the power of the motor generator MG2. In the CD mode, the engine 200 is basically in the engine stop state (in some cases, the minimum engine operation for supplying power to the auxiliary equipment may be performed), so the fuel consumption is zero or ignored. There is little to do. However, since the CD mode is a traveling mode inclined to the discharge side in the power balance of the battery 30, the SOC of the battery 30 basically continues to decrease. Therefore, whether or not the CD mode can be executed is determined in consideration of the SOC of the battery 30.

<Overview of indicator control processing>
Except when accompanied by engine operation for auxiliary power generation, during the CD mode travel in which the engine 200 is in the engine stop state, the engine 200 is started when a predetermined condition is satisfied. Notifying the driver of the engine start timing is useful both in the sense of encouraging economical driving and in the sense of providing judgment criteria to a driver who intends to drive economically. For this reason, in the hybrid vehicle 1, information related to the engine start timing is displayed on the indicator 40.

  Here, the display content of the indicator 40 will be described visually with reference to FIG. Here, FIG. 3 is a diagram illustrating the display content of the indicator 40. In the figure, the same reference numerals are assigned to the same parts as those in FIG. 1, and the description thereof is omitted as appropriate.

  In FIG. 3, an output bar 41 is displayed on the display unit of the indicator 40. The output bar 41 is a display frame whose left end corresponds to an output 0 (kW) and whose right end corresponds to a maximum output value Pmax that can travel in the CD mode. The output bar 41 is a current output value that is the current output value of the hybrid vehicle 1 with respect to the maximum output value Pmax (that is, an example of the “current output value” according to the present invention). For the sake of convenience, the ratio (% treated as being equal to the required output value Pn of the hybrid vehicle 1) is displayed as a display value I (see hatching display in the figure).

  When the display value I reaches the maximum output value Pmax (that is, 100%) corresponding to the right end of the output bar 41 or exceeds the maximum output value, the engine 200 is started. Therefore, the driver can continue the economical driving by keeping an eye on the transition of the display value I and keeping in mind that the display value I does not reach the maximum value.

  Note that when the engine 200 is started, the traveling mode shifts to the CS mode. Therefore, the display content of the indicator 40 is mainly the display bar for the CS mode located on the right side of the output bar 41 (see the CS area in the drawing). When the output value of the hybrid vehicle 1 becomes zero, the hybrid vehicle 1 is recognized as a non-running state, and the display content of the indicator 40 is mainly a display bar for charging (refer to the CHG area shown in the drawing). However, various changes can be made individually and specifically to the display content and display method of information in the indicator 40.

  By the way, the maximum output value Pmax corresponding to the right end of the output bar 41 includes a first maximum output value Pmax1 (an example of “first required output value” according to the present invention) and a second maximum output value Pmax2 (main There are two types of “second required output value” according to the invention.

  The second maximum output value Pmax2 is a physical maximum output value of the motor generator MG2, and is a value determined according to the discharge limit value Wout, SOC, battery temperature Tbat, etc. of the battery 30 in addition to the specifications of the motor generator MG2. It is. If the SOC of the battery 30 is sufficiently high, the second maximum output value Pmax basically hardly changes during one CD mode traveling period. Accordingly, the display value I of the indicator 40 when the maximum output value Pmax is the second maximum output value Pmax2 increases when the required output value Pn increases, for example, when the accelerator opening degree Ta increases, and the accelerator opening degree Ta. Decreases if the required output value Pn decreases, for example, by decreasing. That is, the display value I does not show an unnatural change, and the display value I is consistent with the driver's feeling.

  On the other hand, the first maximum output value Pmax1 is a value determined by the driving force F required by the driving wheel DW (that is, the required driving force Ft). The driving force can be converted into the required torque of the drive shaft 500, that is, the above-described drive shaft required torque Tpn by considering the tire diameter, the differential gear ratio, the gear ratio of the speed reduction mechanism 600, and the like. When the drive shaft required torque Tpn exceeds the physical limit value of the MG2 torque Tmg2, which is the output torque of the motor generator MG2, the drive force requirement (torque requirement) even if the required output value Pn is within the output possible range of MG2. Is not satisfied, engine 200 starts.

  Here, since the output value is proportional to the product of the torque value and the rotational speed, the value of the drive shaft required torque Tpn can be converted into an output value in consideration of the vehicle speed. As a result, the first maximum output value Pmax1 increases as the vehicle speed increases even if the drive shaft required torque Tpn is constant.

  Therefore, when the first maximum output value Pmax1 is applied as the maximum output value Pmax, the value at the right end of the output bar 41 changes as the vehicle speed increases. As a result, the display value I decreases as the vehicle speed increases. Such an unnaturally decreasing change in the display value I is not consistent with the driver's feeling, and thus causes the driver to feel uncomfortable or uncomfortable. Such a phenomenon and a problem can occur remarkably, for example, when the required output value Pn does not change greatly, for example, when the accelerator opening is constant and only the vehicle speed increases.

  Such a problem is a problem that occurs when the output bar 41 of the indicator 40 is to be shared by the output scale. However, from the viewpoint of the driver, it is only necessary to be able to determine the starting point of the engine 200. Therefore, it is not desirable to display a plurality of information related to the starting timing of the engine 200. That is, in practical operation, the indicator 40 has a start timing based on the output requirement (a start timing defined by the display value I when the second maximum output value Pmax2 is applied as the maximum output value Pmax), and driving. One of the start timings based on the force requirement (start timing defined by the display value I when the first maximum output value Pmax1 is applied as the maximum output value Pmax) is determined to come earlier (that is, simply) It is desirable to display the relatively larger display value I). Therefore, processing for solving the above-described problem is required. The indicator control process is a process for solving such a problem.

<Details of indicator control processing>
Next, details of the indicator control process will be described. FIG. 4 is a flowchart of the indicator control process. The indicator control process is a process that is repeatedly executed at a predetermined cycle during the CD mode traveling.

  In FIG. 4, the ECU 100 acquires various information necessary for display control of the indicator 40 (step S101). In the present embodiment, the vehicle speed V, the accelerator opening degree Ta, the first maximum output value Pmax1, and the second maximum output value Pmax2 are acquired.

  The first maximum output value Pmax1 is the maximum output value based on the driving force requirement as described above, and is obtained by multiplying the maximum value Tmg2max of the MG2 torque Tmg2 by the MG2 rotational speed Nmg2. The MG2 rotational speed Nmg2 may be calculated by time-differentiating the rotational angle detected by a resolver (not shown) in FIG. 2, but the MG2 rotational speed Nmg2 is the rotational speed of the drive shaft 500 as described above. Therefore, the rotational speed of the drive shaft 500 obtained from the vehicle speed V and the speed reduction ratio of the speed reduction mechanism 600 may be substituted. The second maximum output value Pmax2 is a maximum value based on the output requirement, and is obtained from the specifications of the motor generator MG2, the SOC of the battery 30, the charge / discharge limit value, and the like as described above.

  When various types of information are acquired, the maximum output value Pmax is determined (step S102). The maximum output value Pmax is determined to be the smaller one of the first maximum output value Pmax1 and the second maximum output value Pmax2 acquired in step S101.

  When the maximum output value Pmax is determined, a reference display value Ib (%) that is a reference value of the display value I of the indicator 40 is calculated according to the following equation (3) (step S103).

Ib = Pn / Pmax · 100 (3)
In the above equation (3), Pn is the required output value of the hybrid vehicle 1 as described above. Since the required output is covered by the motor generator MG2 in the CD mode, the required output value Pn is equivalent to the current output value of the motor generator MG2.

  The required output value Pn is determined by a known method from the vehicle speed V and the accelerator opening degree Ta. For example, in obtaining the required output value Pn, the required driving force Ft of the hybrid vehicle 1 is determined from the vehicle speed V and the accelerator opening degree Ta. The required driving force Ft is performed, for example, by selecting a corresponding value from the required driving force map. When the required drive force Ft is obtained, the required drive force Ft is converted into a drive shaft request torque Tpn that is a request torque of the drive shaft 500. When the drive shaft request torque Tpn is obtained, the drive shaft request output value is obtained from the drive shaft request torque Tpn and the rotational speed of the drive shaft 500. Strictly speaking, the required output value Pn of the hybrid vehicle 1 is a value obtained by adding the output value for consumption of auxiliary equipment to the drive shaft required output value, but here, the output value for consumption of auxiliary equipment is ignored. Therefore, here, the drive shaft required output value is treated as the required output value Pn. This is an example of control.

  When the reference display value Ib is determined, the hysteresis value hs is determined (step S104). The hysteresis value hs is a kind of correction value for suppressing a change in the display value Ib of the indicator 40. The hysteresis value hs is stored in advance in a storage unit such as a ROM or a flash memory in association with the vehicle speed V and the accelerator opening degree Ta (for example, as a control map).

  When the hysteresis value hs is obtained, the ECU 100 performs a hysteresis process based on the hysteresis value hs and determines a final display value I (step S105). When the display value I is determined, this display value I is displayed on the display unit of the indicator 40, and the indicator control process is ended. As already described, the indicator control process is a process that is repeated at a predetermined cycle, and is executed again from step S101 after a predetermined interval after the end.

  Here, the details of the hysteresis value hs will be described with reference to FIG. FIG. 5 is a diagram for explaining the concept of the hysteresis value.

  In FIG. 5, the hysteresis value hs is given a value of 0 to 18 for each concentric rectangular annular region defined by the vehicle speed V and the accelerator opening degree Ta (that is, each region surrounded by a broken line). . As shown in the figure, the hysteresis value hs is smaller in the outer concentric rectangular annular region, and takes a maximum value of 18 at an intermediate vehicle speed of about 50 km / h and an intermediate accelerator opening of about Ta = 35%.

  In FIG. 5, traveling conditions in which the hysteresis value hs falls within a certain range (for example, 16 to 18) are collectively displayed as one concentric rectangular annular region. However, the actual hysteresis value hs is determined based on the vehicle speed V and the accelerator. One fixed value is taken for one traveling condition defined by the opening degree Ta. In the region outside the outermost concentric rectangular annular region, the hysteresis value hs = 0 (that is, the minimum value).

  The meaning of the hysteresis value hs varies depending on the contents of the hysteresis processing. In the present embodiment, the larger the hysteresis value hs, the more the change in the display value I of the indicator 40 is suppressed.

  Here, a specific hysteresis process is illustrated.

<First example of hysteresis processing>
The hysteresis processing according to the present embodiment is executed, for example, according to the following equations (4) and (5). Note that the current display value of the indicator 40 is I (i), and the display value of the indicator 40 after the update is I (i + 1).

I (i + 1) = Ib (4)
I (i + 1) = I (i) − (I (i) −Ib) + hs (5)
Here, when the above formula (4) is applied, the reference display value Ib is used as it is as the update value I (i + 1), so that the change of the display value I is not suppressed. The above expression (4) is applied when the following condition (4a) or (4b) is satisfied.

Pmax = Pmax2 (4a)
I (i) ≦ Ib (4b)
That is, when the second maximum output value Pmax2 based on the output requirement is applied as the maximum output value Pmax, the reliability of the display value I does not decrease, and therefore the change in the display value I is not suppressed (Condition 4a ). In addition, regarding the change on the increase side of the display value I, the reliability of the display value I does not decrease, so the change of the display value I is not suppressed (condition 4b).

  When the above equation (5) is applied, the change in the display value I is suppressed according to the hysteresis value hs. The above equation (5) is applied when the following conditions (5a) and (5b) are satisfied.

Pmax = Pmax1 (5a)
I (i)> Ib (5b)
That is, only when the first maximum output value Pmax1 based on the driving force requirement is applied as the maximum output value Pmax (condition 5a) and the display value I changes to the decreasing side (condition 5b), the change in the display value I Is suppressed. When the above equation (5) is applied, the maximum value of the update value I (i + 1) is the current value I (i). That is, any decrease in the display value I whose absolute value does not exceed the hysteresis value hs is ignored, and the display value I is maintained. Further, for a decrease change in which the absolute value exceeds the hysteresis value hs, the decrease width of the display value I is canceled by the hysteresis value hs.

<Second example of hysteresis processing>
The above formula (5) may be replaced by the following formula (6).

I (i + 1) = I (i) − (I (i) −Ib) / hs (6)
When the above equation (6) is applied, the display value I decreases in response to a request to decrease the display value I (that is, when the reference display value Ib obtained in step S103 is smaller than the current value I (i)). However, the amount of decrease is canceled according to the hysteresis value hs. Therefore, the decrease change of the display value I is suppressed. Needless to say, the minimum value of the hysteresis value hs is “1” on the assumption that the above equation (6) is applied.

As described above, according to the indicator control process according to the present embodiment, the first maximum output value Pmax1 based on the driving force requirement is a function of the vehicle speed V, which is remarkable in the intermediate vehicle speed region and the intermediate accelerator opening region. The unnatural decrease in the display value I of the indicator 40 occurring in the above is suppressed by the hysteresis process. For this reason, the discomfort and discomfort that the display value I gives to the driver is alleviated and ideally prevented.

  Although not illustrated in FIG. 4, the change in the display value I of the indicator 40 to an unnatural decrease side occurs remarkably when the vehicle speed V increases and the accelerator opening degree. This is a case where the increase range of Ta is within a predetermined value. In view of this point, in FIG. 4, a determination process for the vehicle speed V and the accelerator opening degree Ta may be inserted between step S103 and step S104. More specifically, the reference display value Ib may be determined as the display value I when the vehicle speed V has not increased, or when the accelerator opening degree Ta has decreased or has increased significantly. .

Second Embodiment
In the first embodiment, a method for suppressing an unnatural decrease in the display value I that occurs remarkably mainly in the middle vehicle speed region and the intermediate accelerator opening region has been described. In the second embodiment, while maintaining the effect of the first embodiment, an indicator control process capable of suppressing an unnatural increase in the display value I that may occur in a low vehicle speed region and a small accelerator opening region, This will be described with reference to FIG. FIG. 6 is a flowchart of the indicator control process according to the second embodiment. In the figure, the same parts as those in FIG. 4 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  In FIG. 6, when the reference display value Ib is determined (step S103), the reflection coefficient K is determined (step S201). The reflection coefficient K is a coefficient representing the degree of reflection of the reference display value Ib to the display value I. The reflection coefficient K is stored in advance in a storage unit such as a ROM or a flash memory in association with the vehicle speed V and the accelerator opening degree Ta (for example, as a control map).

  When the reflection coefficient K is determined, the ECU 100 calculates the correction reference display value Ibc according to the following equation (7) (step S202).

Ibc = K · Ib (7)
When the correction reference display value Ibc is calculated, a hysteresis process similar to that of the first embodiment is executed based on the correction reference display value Ibc (steps S104 and S105).

  Here, the reflection coefficient K will be described with reference to FIG. FIG. 7 is a diagram for explaining the concept of the reflection coefficient K.

  In FIG. 7, the reflection coefficient K is given a value of 0 to 1 for each illustrated band-like region (each hatched region surrounded by a broken line) defined by the vehicle speed V and the accelerator opening degree Ta. As shown in the figure, the reflection coefficient K has a smaller value on the lower vehicle speed side and on the smaller accelerator opening side.

  In FIG. 7, traveling conditions in which the reflection coefficient K falls within a certain range (for example, 0 to 0.1) are collectively displayed as one band-like region. However, the actual reflection coefficient K is calculated based on the vehicle speed V and the accelerator. One fixed value is taken for one traveling condition defined by the opening degree Ta. The reflection coefficient K = 1 (maximum value) in the region outside the outermost strip region where the reflection coefficient K takes a value of 0.9 to 1.0.

  Here, when the corrected reference display value Ibc calculated according to the above equation (7) is applied, the reference display of the indicator 40 is displayed in a travel region (for example, a creep travel region) corresponding to a low vehicle speed and a small accelerator opening. The value Ib is a small value substantially corresponding to zero. That is, the reference display value Ib is hardly reflected in the display value I.

  As described above, the first maximum output value Pmax1 based on the driving force requirement increases or decreases according to the level of the vehicle speed. For this reason, contrary to the unnatural decrease change of the display value I in the intermediate vehicle speed region and the intermediate accelerator opening region described in the first embodiment, the first maximum output value Pmax1 is extremely low and small. In the accelerator opening region, the display value I of the indicator 40 increases unnaturally.

  In response to such a problem, according to the indicator control process according to the present embodiment, the reference display value Ib of the indicator 40 is corrected to be decreased by the reflection coefficient K in the travel region where the unnatural increase change occurs. For this reason, the discomfort and discomfort that the display value I gives to the driver is alleviated and ideally prevented.

  In addition, the values of the vehicle speed V and the accelerator opening degree Ta referred to in the first and second embodiments are all examples, and specific numerical values thereof can be freely changed.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and control of a hybrid vehicle involving such a change. The apparatus is also included in the technical scope of the present invention.

  The present invention is applicable to battery protection for hybrid vehicles.

  DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle, 10 ... Hybrid drive device, 20 ... PCU, 30 ... Battery, 40 ... Indicator, MG1, MG2 ... Motor generator, 100 ... ECU, 200 ... Engine, 300 ... Power split mechanism, 400 ... Input shaft, 500 ... drive shaft, 600 ... deceleration mechanism.

Claims (4)

Display means;
An internal combustion engine;
A hybrid vehicle control device for controlling a hybrid vehicle including at least one rotating electric machine,
A first required output value of the hybrid vehicle that requires starting of the internal combustion engine due to a lack of torque of the rotating electrical machine during a period in which the hybrid vehicle travels using only the rotating electrical machine as a power source is calculated. First calculating means;
Second calculating means for calculating a current output value of the hybrid vehicle;
Display control means for controlling the display means so that a ratio between the calculated first required output value and the calculated current output value is displayed;
A control device for a hybrid vehicle, comprising: suppression means for suppressing a change in the displayed ratio based on a vehicle speed and an accelerator opening. The first calculating means is a second hybrid vehicle that requires starting of the internal combustion engine due to insufficient output of the rotating electrical machine during a period in which the hybrid vehicle travels using only the rotating electrical machine as a power source. Further calculate the required output value of
The display control means displays the ratio between the smaller one of the calculated first required output value and the second required output value and the calculated current output value. Control
The suppression means suppresses a change in the displayed ratio when a ratio between the calculated first requested output value and the calculated current output value is displayed. The hybrid vehicle control device according to claim 1. The said suppression means maintains the said ratio displayed when the driving | running | working area | region of the said hybrid vehicle determined by the said vehicle speed and accelerator opening corresponds to a predetermined | prescribed area | region. Control device for hybrid vehicle. The said suppression means suppresses the reduction | decrease of the said ratio when the said accelerator opening is constant or is increasing, and the said vehicle speed is rising. Any one of Claim 1 to 3 characterized by the above-mentioned. The control apparatus of a hybrid vehicle as described in the item.

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