JP2014040199A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control device which performs reverse traveling with a driving force satisfying a driver's requirement and prevents the driver from feeling discomfort due to insufficient driving force.SOLUTION: In charging reverse traveling, a target engine speed Net is set based on an accelerator opening Acc and a temperature K of an electric motor MG2, and an engine and an electric generator MG1 are controlled so that an actual engine speed Ne equals the target engine speed Net (S1 to S12). Thus, even if a torque Tm2r of the electric motor MG2 is restricted with increase of the temperature K of the electric motor MG2, charging reverse traveling can be performed with a driving force corresponding to the accelerator opening Acc required by a driver.

Description

  The present invention relates to a vehicle control device used in a so-called hybrid vehicle equipped with an internal combustion engine and an electric motor as drive sources.

  Conventionally, as this type of hybrid vehicle, a planetary gear mechanism in which three rotating elements are connected to a driving shaft coupled to an axle, an output shaft of an engine, and a rotating shaft of a motor generator MG1, and power can be output to the driving shaft There is a known motor generator MG2 (see, for example, Patent Document 1).

  The vehicle control device mounted on this hybrid vehicle changes the required power for the engine according to the uphill slope at the time of reverse running on the uphill road while charging the battery using the power from the engine. ing. For example, when the uphill slope is large, the charging power is reduced and the required power for the engine is set smaller than when the climbing slope is small. This makes it possible to reduce the torque in the forward direction that acts on the drive shaft out of the torque output from the engine when traveling reversely on an uphill road with a large climbing slope, which increases the climbing performance during reverse traveling. Can be improved.

JP 2010-195255 A

  However, in the conventional vehicle control device described in Patent Document 1, although the climbing performance when traveling reversely on the climbing road while charging the battery using the power from the engine is considered, No consideration has been given to how to compensate for the driving force that decreases when the torque output from the motor generator MG2 decreases due to its temperature characteristics when the motor generator MG2 becomes hot during traveling.

  For this reason, in the conventional vehicle control device, when the motor generator MG2 becomes high temperature during reverse running and the output torque of the motor generator MG2 decreases, it becomes impossible to output the driving force that meets the driver's request, and the driver feels uncomfortable. There was a problem.

  The present invention has been made in order to solve the above-described problems, and can perform reverse traveling with a driving force that meets the driver's request and prevents the driver from feeling uncomfortable due to insufficient driving force. An object of the present invention is to provide a vehicular control device.

  In order to achieve the above object, a vehicle control apparatus according to the present invention includes (1) an internal combustion engine, a generator capable of inputting / outputting power, an output shaft of the internal combustion engine, a rotating shaft of the generator, and a drive wheel. A planetary gear mechanism in which three rotating elements are connected to three shafts connected to a drive shaft, an electric motor capable of inputting / outputting power to / from the drive shaft, and a power storage means for exchanging electric power with the generator and the electric motor And an electric vehicle temperature detecting means for detecting the temperature of the electric motor, and charging the power storage means using a part of the power output from the internal combustion engine. If the motor torque output from the motor is limited when the temperature of the motor reaches a predetermined temperature during reverse running, the drive shaft is limited by the motor torque limit. Out As the power to be increased, has a configuration and a control means for executing a charge reverse drive control for increasing the engine speed of the internal combustion engine while maintaining the engine output of the internal combustion engine.

  With this configuration, in the vehicle control device according to the present invention, the motor torque is limited by the temperature of the motor reaching a predetermined temperature when traveling reversely while charging the power storage means using the power from the internal combustion engine. In this case, charge reverse running control is executed to increase the engine speed while maintaining the engine output so that the power output to the drive shaft is increased by the limit of the motor torque.

  For this reason, even if the motor torque is limited when performing reverse running while the internal combustion engine is operated, the drive shaft out of the engine torque output from the internal combustion engine by increasing the engine speed It is possible to reduce the forward torque acting on the. As a result, the power output to the drive shaft can be increased by the limit of the motor torque.

  Therefore, the vehicle control apparatus according to the present invention can perform reverse traveling with a driving force that meets the driver's request, and can prevent the driver from feeling uncomfortable due to insufficient driving force.

  Further, the vehicle control device according to the present invention is the vehicle control device according to (1), wherein (2) the control means is the motor detected by the motor temperature detection means in the charging reverse travel control. As the temperature of the engine increases, the engine speed increases.

  With this configuration, the vehicle control device according to the present invention increases the increase amount of the engine speed as the temperature of the motor increases in the charge reverse travel control. That is, when the limit amount of the motor torque increases as the temperature of the motor increases, the increase amount of the engine speed is increased along with the increase of the limit amount.

  As a result, the amount of decrease in the forward torque acting on the drive shaft among the engine torque output from the internal combustion engine can be increased as the motor torque limit amount increases. Therefore, by appropriately changing the amount of decrease in the forward torque acting on the drive shaft in accordance with the change in the motor torque limit amount, even if a change in the motor torque limit amount occurs, the drive that meets the driver's request Reverse running can be done with force.

  The vehicle control device according to the present invention is the vehicle control device according to (1) or (2), further comprising: (3) an accelerator opening detection unit that detects an accelerator opening of the vehicle; The control means has a configuration in which the amount of increase in the engine speed is increased as the accelerator opening detected by the accelerator opening detection means in the charging reverse travel control is larger.

  With this configuration, the vehicle control device according to the present invention increases the amount of increase in the engine speed as the accelerator opening increases in the charge reverse travel control. As a result, reverse traveling can be performed with a driving force corresponding to the accelerator opening required by the driver.

  The vehicle control device according to the present invention is the vehicle control device according to any one of the above (1) to (3), wherein (4) the control means performs the charge reverse travel control, A target engine speed is set based on the accelerator opening detected by the accelerator opening detecting means and the motor temperature detected by the motor temperature detecting means, and the engine speed becomes the target engine speed. The internal combustion engine and the generator are controlled.

  With this configuration, the vehicle control device according to the present invention sets the target engine speed based on the accelerator opening and the temperature of the electric motor when the charging reverse travel control is executed, and the engine speed becomes the target engine speed. Control the internal combustion engine and generator. Thereby, even if it is a case where an electric motor torque is restrict | limited with the temperature rise of an electric motor, reverse driving | running | working can be performed with the driving force according to the accelerator opening which a driver | operator requires.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle control apparatus which can perform reverse driving | running | working with the driving force corresponding to a driver | operator's request | requirement, and can prevent a driver | operator from feeling uncomfortable by lack of driving force can be provided. .

1 is a schematic configuration diagram of a hybrid vehicle to which a vehicle control device according to an embodiment of the present invention is applied. (A) is the graph which showed the relationship between the conventional accelerator opening and MG2 torque according to MG2 temperature, (b) is the graph which showed the relationship between the conventional accelerator opening and driving force according to MG2 temperature. is there. It is explanatory drawing which shows a mode that an example of the operating line of the engine which concerns on embodiment of this invention, a target engine speed, and a target engine torque are set. It is a flowchart which shows charge reverse running control performed by HVECU which concerns on embodiment of this invention. It is explanatory drawing which shows an example of the map for request | requirement torque setting which concerns on embodiment of this invention. It is explanatory drawing which shows an example of the alignment chart for demonstrating dynamically the rotation element of the power division | segmentation integration mechanism which concerns on embodiment of this invention. It is a graph which shows MG2 torque according to MG2 temperature. It is a map for target engine speed calculation used for charge reverse running control of an embodiment of the invention. (A) is a graph which shows the relationship between MG2 temperature and engine speed in embodiment of this invention, (b) is a graph which shows the relationship between MG2 temperature and engine torque in embodiment of this invention. It is. It is a graph which shows the change of the driving force with respect to the accelerator opening degree when the charge reverse running control of embodiment of this invention is performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  With reference to FIGS. 1-10, the vehicle control apparatus which concerns on embodiment of this invention is demonstrated. The vehicle control device according to the present embodiment is applied to a vehicle equipped with an internal combustion engine and an electric motor (generator) as a power source for generating a driving force of the vehicle, a so-called hybrid vehicle.

  As shown in FIG. 1, the hybrid vehicle 1 includes an engine 2, a power distribution and integration mechanism 3, motor generators MG <b> 1 and MG <b> 2, a reduction gear 4, a battery 80, and a vehicle control device 10. ing.

  The vehicle control apparatus 10 includes a hybrid electronic control apparatus (hereinafter simply referred to as HVECU) 100, an engine electronic control apparatus (hereinafter simply referred to as engine ECU) 200, and a motor electronic control apparatus (hereinafter simply referred to as motor ECU). ) 300 and a battery electronic control device (hereinafter simply referred to as a battery ECU) 400. HVECU 100 in the present embodiment constitutes a control means according to the present invention.

  The engine 2 is configured as an internal combustion engine capable of outputting power using a hydrocarbon fuel such as gasoline or light oil. The engine 2 injects gasoline from a fuel injection valve (not shown), mixes the sucked air and gasoline, and sucks this mixture into the fuel chamber. Next, the engine 2 explosively burns the intake air-fuel mixture, and converts the reciprocating motion of a piston (not shown) that is pushed down by the energy into the rotational motion of the crankshaft 27.

  The engine 2 is controlled by the engine ECU 200. Various sensors such as a crank angle sensor and a water temperature sensor are connected to the engine ECU 200. The engine ECU 200 calculates the engine speed based on a signal input from, for example, a crank angle sensor. The engine ECU 200 outputs various control signals for driving the engine 2, such as a drive signal to the fuel injection valve, a drive signal to the throttle motor that adjusts the throttle opening degree, and a control signal to the ignition coil. To output.

  The engine ECU 200 is in communication with the HVECU 100, controls the operation of the engine 2 by a control signal from the HVECU 100, and outputs data related to the operating state of the engine 2 as necessary.

  The power distribution and integration mechanism 3 is a triaxial power distribution and integration mechanism connected to the crankshaft 27 via a damper 30. The power distribution and integration mechanism 3 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and the ring gear 32, and a plurality of pinion gears 33. And a carrier 34 that is rotatably and revolved. That is, the power distribution and integration mechanism 3 is configured as a planetary gear mechanism that performs a differential action with the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. As will be described later, these three rotating elements are connected to driving wheels 63a and 63b via a sun gear 31 connected to a rotating shaft 36 of motor generator MG1 so as to be integrally rotatable, a counter drive gear 35 and a gear mechanism 60. The ring gear shaft 32a serving as a drive shaft and the crankshaft 27 serving as the output shaft of the engine 2 are connected to three shafts, respectively.

  Carrier 34 is connected to crankshaft 27, and sun gear 31 is connected to motor generator MG1. The ring gear 32 is coupled to the reduction gear 4 via a ring gear shaft 32a. A counter drive gear 35 is connected to the ring gear shaft 32a. The counter drive gear 35 meshes with the gear mechanism 60.

  When motor generator MG1 functions as a generator, power distribution integration mechanism 3 distributes power from engine 2 input from carrier 34 to sun gear 31 side and ring gear 32 side according to the gear ratio. On the other hand, power distribution integration mechanism 3 integrates the power from engine 2 input from carrier 34 and the power from motor generator MG1 input from sun gear 31 when motor generator MG1 functions as an electric motor. Output to the side. The power output to the ring gear 32 is finally output from the counter drive gear 35 to the drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  The reduction gear 4 includes a sun gear 41 connected to the motor generator MG2, a ring gear 42 disposed concentrically with the sun gear 41, a plurality of pinion gears 43 that mesh with the sun gear 41 and the ring gear 42, and one end fixed to the body case. The other end includes a carrier 44 having a support shaft that rotatably supports the pinion gear 43. The reduction gear 4 constitutes a planetary gear mechanism that decelerates the rotation transmitted from the motor generator MG2 using the sun gear 41, the ring gear 42, and the pinion gear 43 as rotational elements to amplify the drive torque.

  When the motor generator MG2 functions as an electric motor, the reduction gear 4 decelerates the rotation transmitted from the motor generator MG2, amplifies the drive torque, and outputs it from the ring gear 42. On the other hand, the reduction gear 4 causes the motor generator MG2 to function as a generator by accelerating the rotation by the power input to the ring gear 42 to attenuate the drive torque and outputting it from the sun gear 41.

  The motor generators MG1 and MG2 are known synchronous generator motors that have a function as an electric motor that converts supplied electric power into mechanical power and a function as an electric generator that converts input mechanical power into electric power. It is configured. That is, motor generators MG1 and MG2 are configured as a generator and an electric motor that can input and output power. Motor generator MG1 is mainly used as a generator, and motor generator MG2 is mainly used as an electric motor. Motor generator MG1 in the present embodiment constitutes a generator according to the present invention, and motor generator MG2 constitutes an electric motor according to the present invention.

  Motor generators MG 1 and MG 2 exchange power with battery 80 via inverters 81 and 82. The power line 83 connecting the inverters 81 and 82 and the battery 80 is configured as a positive and negative bus shared by the inverters 81 and 82, and other power generated by the motor generators MG1 and MG2 is used. It can be consumed by motor generators. Therefore, battery 80 is charged / discharged by electric power generated from one of motor generators MG1 and MG2 or insufficient electric power. In addition, if the balance of electric power is balanced by motor generators MG1 and MG2, battery 80 is not charged / discharged.

  Motor generators MG1 and MG2 are both driven and controlled by motor ECU 300. The motor ECU 300 includes signals necessary for driving and controlling the motor generators MG1 and MG2, such as signals from rotational position detection sensors 85 and 86 for detecting the rotational positions of the rotors of the motor generators MG1 and MG2, and current sensors (not shown). The phase current applied to the motor generators MG1 and MG2 detected by the above is input. The motor ECU 300 outputs a switching control signal to the inverters 81 and 82.

  Motor ECU 300 is in communication with HVECU 100, and controls driving of motor generators MG1 and MG2 by a control signal from HVECU 100, and outputs data relating to the operating state of motor generators MG1 and MG2 to HVECU 100 as necessary. Motor ECU 300 calculates rotational speeds Nm1 and Nm2 of motor generators MG1 and MG2 based on signals from rotational position detection sensors 85 and 86.

  In addition, motor temperature sensor 87 for detecting the temperature of motor generator MG2 (hereinafter referred to as MG2 temperature K) is connected to motor ECU 300. The motor temperature sensor 87 is configured to transmit the detected MG2 temperature K to the motor ECU 300. The motor temperature sensor 87 in the present embodiment constitutes a motor temperature detecting means according to the present invention. The “motor temperature detection means” is not limited to the motor temperature sensor 87 directly attached to the motor generator MG2, and for example, the MG2 temperature K is estimated based on the temperature of the cooling medium that cools the motor generator MG2. As long as the MG2 temperature K can be detected, any method may be used.

  Further, motor ECU 300 also calculates upper limit torque Tm2lim, which is an upper limit value of torque that may be output from motor generator MG2, based on MG2 temperature K from motor temperature sensor 87. Although not shown in detail, the upper limit torque of motor generator MG1 is calculated in the same manner.

  The battery 80 is configured as a chargeable / dischargeable secondary battery made of nickel metal hydride, lithium ions, or the like. Battery 80 exchanges power with motor generators MG1 and MG2. Battery 80 in the present embodiment constitutes a power storage unit according to the present invention.

  The battery 80 is managed by the battery ECU 400. The battery ECU 400 is attached to a signal necessary for managing the battery 80, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 80, and a power line 83 connected to the output terminal of the battery 80. The charging / discharging current from the current sensor (not shown), the battery temperature Tb from the battery temperature sensor 88 attached to the battery 80, and the like are input.

  Battery ECU 400 outputs data related to the state of battery 80 to HVECU 100 by communication as necessary. Further, the battery ECU 400 calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 80, or calculates the remaining capacity (SOC) and the battery temperature Tb. The input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 80, are calculated based on the above. For example, these input / output limits Win and Wout can be set by multiplying the temperature dependent values based on the respective battery temperatures Tb by the input limiting correction coefficient or the output limiting correction coefficient based on the remaining capacity (SOC) of the battery 80. is there. Further, these input / output limits Win and Wout may be obtained by calculation, for example, by referring to an input / output limit map in which the remaining capacity (SOC) and the battery temperature Tb are related in advance.

  The HVECU 100 is configured as a microprocessor centered on the CPU 100a, and includes a ROM 100b that stores a processing program, a RAM 100c that temporarily stores data, and an input / output port and a communication port (not shown).

  An ignition switch 101, an accelerator pedal position sensor 102, a vehicle speed sensor 103, and a shift position sensor 104 are connected to the HVECU 100. The ignition switch 101 outputs an ignition signal to the HVECU 100 in accordance with a user operation. The accelerator pedal position sensor 102 detects the accelerator opening Acc based on the operation amount of the accelerator pedal 8 and outputs a signal corresponding to the accelerator opening Acc to the HVECU 100. The vehicle speed sensor 103 detects the vehicle speed V of the hybrid vehicle 1 and outputs a signal corresponding to the vehicle speed V to the HVECU 100. The accelerator pedal position sensor 102 in the present embodiment constitutes an accelerator opening detecting means according to the present invention.

  Shift position sensor 104 detects the operating position (shift position SP) of shift lever 9 and outputs a signal corresponding to shift position SP to HVECU 100. Examples of the shift position SP include a parking position (P position) for parking, a traveling position (D position) for forward traveling, and a reverse position (R position) for reverse traveling.

  As described above, the HVECU 100 is connected to the engine ECU 200, the motor ECU 300, and the battery ECU 400 via a communication port, and exchanges various control signals and data with the engine ECU 200, the motor ECU 300, and the battery ECU 400.

  In the hybrid vehicle 1 configured as described above, the user request power is calculated based on the accelerator operation amount Acc and the vehicle speed V, and the request power corresponding to the user request power is output to the counter drive gear 35. 2 and motor generators MG1 and MG2 are controlled. Moreover, as a driving mode of the hybrid vehicle 1, there are a hybrid driving mode, a motor driving mode, a regenerative driving mode, etc., for example.

  In the hybrid travel mode, the hybrid vehicle 1 is caused to travel using both the engine 2 and the motor generator MG2 as driving force sources while the motor generator MG1 generates power using the engine output of the engine 2. In the motor travel mode, the hybrid vehicle 1 is traveled using the motor generator MG2 as a driving force source while the engine 2 is stopped. The regenerative travel mode is a travel mode in which the motor generator MG2 generates power using energy input via the gear mechanism 60 when a predetermined condition such as a deceleration request is established.

  Next, the operation of the hybrid vehicle 1 according to the present embodiment configured as described above, in particular, the operation when traveling reversely while charging the battery 80 using the power from the engine 2 will be described.

  In the hybrid vehicle 1, during reverse running, when the remaining capacity (SOC) of the battery 80 is equal to or greater than a predetermined value (for example, 40%), the torque (hereinafter referred to as “this”) from the motor generator MG2 while the operation of the engine 2 is stopped. The torque is referred to as MG2 torque Tm2. On the other hand, when the remaining capacity (SOC) of the battery 80 reaches less than a predetermined value, it is necessary to charge the battery 80. Therefore, while driving the motor generator MG2, the engine 2 is operated to charge the battery 80. However, it becomes the drive control that reverse travels. Hereinafter, such reverse traveling is referred to as “charging reverse traveling”.

  Here, motor generator MG2 has the property that the output characteristics of MG2 torque Tm2 differ depending on MG2 temperature K, which is its own temperature.

  FIG. 2A is a graph showing how the MG2 torque Tm2 [N · m] output according to the accelerator opening Acc during reverse charging travel varies depending on the height of the MG2 temperature K. Note that the MG2 torque Tm2 [N · m] in FIG. 2A shows a negative value corresponding to the reverse running.

  As shown in FIG. 2 (a), when the MG2 temperature K rises from K1 [° C.] to K2 [° C.] in the range where the accelerator opening Acc is equal to or greater than a predetermined value, the MG2 torque Tm2 [N・ It can be seen that m] decreases. The MG2 temperature K1 [° C.] is a temperature at which the MG2 torque Tm2 [N · m] does not decrease even when the accelerator opening degree Acc increases.

  When the MG2 torque Tm2 [N · m] decreases as the MG2 temperature K increases, as shown in FIG. 2B, the driving force [N ] Also decreases.

The driving force F [N] of the hybrid vehicle 1 during reverse charging travel can be expressed by the following equation (1). In the following equation (1), Tm2 is the MG2 torque [N · m], Gr is the reduction ratio of the reduction gear 4, Te is the engine torque [N · m], ρ is the planetary gear ratio, and ρ _def is the differential ratio of the differential gear 62. , Rt is the tire diameter [m].

  During reverse charging, the sum of the MG2 torque Tm2 [N · m] and the engine torque Te [N · m] is divided by the tire diameter Rt [m] as shown in the above equation (1). This value is output as the driving force F [N].

  Here, of the torque output from the engine 2, the torque (direct torque) acting on the ring gear shaft 32 a via the power distribution and integration mechanism 3 acts on the ring gear shaft 32 a as a forward torque. In the above formula (1), the MG2 torque Tm2 [N · m] is a negative value, whereas the engine torque Te [N · m] is a positive value. For this reason, during charging reverse traveling, the direct torque acts as torque in the direction opposite to the traveling direction (reverse direction).

  Therefore, in normal times (for example, when the MG2 torque Tm2 is not limited), in order to output the required torque to the ring gear shaft 32a when charging reverse travel, the sum of the torque for canceling the direct torque and the required torque Is output from the motor generator MG2. At this time, as shown in FIG. 3, the engine 2 is controlled so as to be operated at a relatively high engine torque Te1 and a relatively low engine speed Ne1 corresponding to the intersection between the required engine power Pe and the optimum operation line. Is done. That is, at the time of normal charge reverse running, the engine 2 is operated in a low rotation high torque region to achieve fuel efficiency.

  However, when the MG2 temperature K increases, the MG2 torque Tm2 decreases due to the temperature characteristics. In this case, motor generator MG2 cannot output MG2 torque Tm2 that is originally required.

  In such a case, as can be seen from the above equation (1), if the engine torque Te can be reduced along with the reduction in the MG2 torque Tm2, the reduction in the driving force F can be suppressed.

  Therefore, in the present embodiment, in order to compensate for the decrease in MG2 torque Tm2 due to the temperature characteristics of motor generator MG2, the operating point of engine 2 is reduced from the normal operating point to a high rotational speed while maintaining engine power Pe constant. Move to the torque range. That is, as shown in FIG. 3, the engine 2 is operated at an engine torque Te2 lower than the engine torque Te1 and an engine speed Ne2 higher than the engine speed Ne1. As a result, the engine torque Te decreases, so the direct torque also decreases. For this reason, the reverse torque acting on the ring gear shaft 32a is increased by the decrease in the direct torque, and as a result, the decrease in the driving force F can be suppressed.

  Next, with reference to FIG. 4, the charge reverse running control executed by the HVECU 100 during the charge reverse running will be described. This charging reverse running control is repeatedly executed at predetermined time intervals (for example, every several msec).

  As shown in FIG. 4, the HVECU 100 determines whether the shift position SP is the R position based on the detection result of the shift position sensor 104 (step S1).

  When the HVECU 100 determines that the shift position SP is not the R position, the HVECU 100 ends this control.

  On the other hand, when the HVECU 100 determines that the shift position SP is the R position, the accelerator opening Acc from the accelerator pedal position sensor 102, the engine speed Ne calculated by the engine ECU 200, and the MG2 from the motor temperature sensor 87. Processing for inputting various data necessary for reverse charging traveling such as temperature K, vehicle speed V from vehicle speed sensor 103, and rotation speeds Nm1, Nm2 of motor generators MG1, MG2 is executed (step S2). The rotational speeds Nm1 and Nm2 of the motor generators MG1 and MG2 are calculated by the motor ECU 300 based on the rotational position of the rotor detected by the rotational position detection sensors 85 and 86, and input from the motor ECU 300 by communication. .

  Next, the HVECU 100 sets a required torque Tr to be output to the ring gear shaft 32a as a torque required for the hybrid vehicle 1 based on the accelerator opening Acc and the vehicle speed V (step S3). As shown in FIG. 5, the required torque Tr is set by deriving the relationship among the accelerator opening Acc, the vehicle speed V, and the required torque Tr from a predetermined required torque setting map. This required torque setting map is stored in advance in the ROM 100b. In the required torque setting map shown in FIG. 3, since the vehicle is running in reverse, both the vehicle speed V and the required torque Tr are negative values.

  Next, the HVECU 100 sets a required power (engine power) Pe corresponding to the charging power Wb (step S4). Specifically, the HVECU 100 subtracts a value obtained by multiplying the required torque Tr by the rotation speed Nr (= Nm2 / Gr) of the ring gear shaft 32a from a value obtained by multiplying the charging power Wb by the conversion factor k, and further, as a device loss. A value obtained by adding the loss Loss is set as the required power Pe to be output from the engine 2. The charging power Wb is a negative value of power.

  Then, the HVECU 100 sets the base target engine speed Neb and the target engine torque Teb based on the set required power Pe and the optimum operation line shown in FIG. 3 (step S5). The target engine speed Neb and the target engine torque Teb set at this time are the engine speed and the engine torque corresponding to the operating point at which the engine 2 is efficiently operated (the intersection of Pe and the operating line). For example, when the motor generator MG2 is not at a high temperature and the MG2 torque does not decrease, the engine 2 based on the target engine speed Neb and the target engine torque Teb set in step S5. Is controlled to operate.

  Here, the required torque Tr is a negative value as described above, and the rotation speed Nr (= Nm2 / Gr) of the ring gear shaft 32a is also a negative value because the traveling is reverse. Therefore, the power required for traveling expressed as a product of these is a positive value. Further, since the charging power Wb is a negative value, subtracting the value obtained by multiplying this by the conversion factor k adds the absolute value of the charging power Wb multiplied by the conversion factor k. Therefore, the required power Pe is calculated as the sum of the power necessary for traveling, the power necessary for charging the battery 80, and the power corresponding to the loss. The rotational speed Nr of the ring gear shaft 32a can be obtained by dividing the rotational speed Nm2 of the motor generator MG2 by the reduction ratio Gr, or by multiplying the vehicle speed V by the conversion factor k.

Next, the HVECU 100 sets the target motor rotation speed Nm1r and the MG1 required torque Tm1r (step S6). Specifically, the HVECU 100 calculates the target motor rotation speed Nm1r by the following equation (2) using the set target engine rotation speed Neb, the rotation speed Nr of the ring gear shaft 32a, and the planetary gear ratio ρ. Further, HVECU 100 calculates MG1 required torque Tm1r of motor generator MG1 by the following equation (3) based on the calculated target motor rotation speed Nm1r and current rotation speed Nm1.

  Expression (2) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 3. Here, FIG. 6 shows a collinear diagram showing a dynamic relationship between the rotational speed and torque in the rotating element of the power distribution and integration mechanism 3 during reverse charging travel.

  In FIG. 6, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor generator MG1, the C-axis indicates the rotation speed of the carrier 34 that is the engine rotation speed Ne, and the R-axis indicates the rotation speed of the motor generator MG2. The rotation speed Nr of the ring gear shaft 32a obtained by dividing the rotation speed Nm2 by the reduction gear ratio Gr of the reduction gear 4 is shown. The above equation (1) can be easily derived by using this alignment chart.

  Of the two thick arrows on the R axis, the upward arrow indicates the torque at which the torque Tm1 output from the motor generator MG1 acts as a forward torque on the ring gear shaft 32a. This torque can be replaced with a direct torque that acts on the ring gear shaft 32a as a forward torque in the engine torque Te.

  Of the two thick arrows on the R axis, the downward arrow indicates the torque that the MG2 torque Tm2 output from the motor generator MG2 acts on the ring gear shaft 32a via the reduction gear 4. When the MG2 temperature K increases and the MG2 torque Tm2 decreases, the torque acting in the reverse direction decreases.

  Expression (3) is a relational expression in feedback control for rotating the motor generator MG1 at the target motor rotational speed Nm1r. In Expression (3), “k1” in the second term on the right side is the gain of the proportional term, and “k2” in the third term on the right side is the gain of the integral term.

When the target motor speed Nm1r and the MG1 required torque Tm1r are calculated in this way, the MG2 request is output as the torque to be output from the motor generator MG2 using the required torque Tr, the MG1 required torque Tm1r, and the planetary gear ratio ρ from the following equation (4). Torque Tm2r is calculated (step S7). In addition, following Formula (4) can be easily derived from the alignment chart of FIG. 6 mentioned above.

  Next, the HVECU 100 determines whether or not the set MG2 required torque Tm2r is greater than a predetermined torque threshold Tth that is set in advance (step S8). Here, since the MG2 required torque Tm2r is a negative value, the fact that the MG2 required torque Tm2r is larger than the torque threshold value Tth indicates that it is larger on the negative side. That is, when the absolute value of the MG2 required torque Tm2r is compared with the absolute value of the torque threshold Tth, it means that the absolute value of the MG2 required torque Tm2r is larger than the absolute value of the torque threshold Tth.

  Hereinafter, the torque threshold value Tth will be described with reference to FIG. FIG. 7 is a graph showing how the MG2 torque Tm2 [N · m] corresponding to the accelerator opening Acc [%] varies depending on the MG2 temperature [° C.].

  As shown in FIG. 7, the motor generator MG2 has an output characteristic that the MG2 torque Tm2 increases as the accelerator opening Acc increases, but the MG2 temperature K rises to a predetermined temperature Kmin [° C.]. When it reaches, it also has a temperature characteristic in which the MG2 torque Tm2 is limited in a region greater than a predetermined accelerator opening.

  Further, this temperature characteristic has a property that the limited region of the MG2 torque Tm2 is expanded as the MG2 temperature K becomes higher. For example, when the MG2 temperature K is Kmin [° C.], the MG2 torque Tm2 is limited from a region where the accelerator opening Acc is relatively large. On the other hand, when the MG2 temperature K is Kmax [° C.] higher than Kmin [° C.], the MG2 torque Tm2 is limited from a region where the accelerator opening Acc is relatively small. That is, at the MG2 temperature Kmin [° C.], the MG2 torque Tm2 is not limited unless the accelerator opening degree Acc is relatively large, whereas at the MG2 temperature Kmax [° C.], the MG2 torque Tm2 even if the accelerator opening degree Acc is small. Will be limited. Thus, the MG2 torque Tm2 is limited from the stage where the accelerator opening degree Acc is small as the MG2 temperature K becomes higher.

  For this reason, in the present embodiment, when MG2 torque Tm2 exceeding MG2 torque corresponding to accelerator opening Acc1 shown in FIG. 7 is required, MG2 torque Tm2 to be output can be limited depending on MG2 temperature K. There will be sex. Conversely, when MG2 torque Tm2 equal to or lower than MG2 torque corresponding to accelerator opening Acc1 is requested, regardless of MG2 temperature K, MG2 torque Tm2 is not limited. This is because when the accelerator opening Acc is small, the MG2 torque Tm2 is limited, that is, even if the accelerator opening Acc is reduced, the influence on the driving force is small.

  Therefore, in the present embodiment, the above torque threshold Tth is set to the same value as the MG2 torque corresponding to the accelerator opening Acc1 shown in FIG. As a result, when the MG2 required torque Tm2r is equal to or less than the torque threshold Tth, the MG2 torque Tm2 is not limited. Therefore, the engine 2 is operated at the operating point set in step S5 and the charging reverse traveling is performed. it can.

  That is, when the HVECU 100 determines that the set MG2 required torque Tm2r is equal to or less than a predetermined torque threshold Tth set in advance, the target engine speed is set so that the engine 2 is operated at the operating point set in step S5. Neb, target engine torque Teb, and MG1 required torque Tm1r are output, and MG2 required torque Tm2r calculated in step S7 is output (step S12), and this process is terminated.

  On the other hand, if the HVECU 100 determines that the set MG2 required torque Tm2r is greater than a predetermined torque threshold Tth, is the MG2 temperature K higher than a predetermined temperature threshold Kth [° C.]? It is determined whether or not (step S9). Here, the temperature threshold Kth [° C.] is set to the lowest value among the MG2 temperatures K at which the MG2 torque Tm2 is limited, that is, the same value as the MG2 temperature Kmin [° C.] shown in FIG. The temperature threshold Kth [° C.] in the present embodiment corresponds to the predetermined temperature in the present invention.

  When the HVECU 100 determines that the set MG2 required torque Tm2r is equal to or less than a predetermined torque threshold Tth that is set in advance, the MG2 torque Tm2 is not limited, that is, there is no possibility of lowering, so the process proceeds to step S12. Then, this process is terminated.

  On the other hand, when the HVECU 100 determines that the set MG2 required torque Tm2r is greater than a predetermined torque threshold Tth set in advance, the target engine speed Net is substituted for the target engine speed Neb set in step S5. Is set (step S10).

  Specifically, the HVECU 100 calculates the target engine speed Net using a map for calculating the target engine speed shown in FIG. 8 defined so that the target engine speed Net increases as the MG2 temperature K increases. This is set as the target engine speed in place of the target engine speed Neb. This target engine speed calculation map is experimentally obtained in advance and stored in the ROM 100b. The target engine speed Net set by this map is the engine speed that can increase the power output to the ring gear shaft 32a by the limit (decrease) of the MG2 torque Tm2.

  When the target engine speed Net is set, the operating point of the engine 2 deviates from the optimum operating line as shown in FIG. 3, and moves to a high rotation / low torque region such as Ne2 and Te2. That is, in the present embodiment, by increasing the target engine speed Net, the target engine torque Tet can be made lower than the target engine torque Teb set in step S5 while maintaining the engine power Pe.

  Next, the HVECU 100 outputs the set target engine speed Net and MG2 required torque Tm2r (step S11), and ends this process. Although not shown here, a target engine torque Tet lower than the target engine torque Teb is output as the target engine torque. Further, MG1 required torque Tm1r lower than that set in step S6 is output as a motor torque command. The MG1 required torque Tm1r output here decreases with a decrease in the target engine torque based on the relational expression “(−1 / ρ) × Tm1 = {1 / (1 + ρ)} × Te”. It is a thing.

  Next, the effect | action of the vehicle control apparatus 10 which concerns on this Embodiment is demonstrated using FIG. 9, FIG.

  In the present embodiment, as described above, the target engine speed is changed according to the temperature characteristics of motor generator MG2 when performing reverse charging travel. As a result, for example, as shown in FIG. 9A, the engine speed Ne at the MG2 temperature K2 [° C.] at which the decrease in the MG2 torque Tm2 occurs is the MG2 temperature K1 at which the MG2 torque does not decrease. It becomes larger than the engine speed Ne at [° C.].

  For this reason, as shown in FIG. 9B, the engine torque Te at the MG2 temperature K2 [° C.] can be reduced compared to the engine torque Te at the MG2 temperature K1 [° C.].

  When the engine torque Te is thus reduced, the torque (= 1 / (1 + ρ)} × Te) acting as the forward torque on the ring gear shaft 32a is reduced on the R axis of the collinear chart shown in FIG. Can do.

  As a result, as shown in FIG. 10, for example, the driving force [N] of the hybrid vehicle 1 does not change between the MG2 temperature K1 [° C.] and the MG2 temperature K2 [° C.]. That is, even if the MG2 temperature K rises and the MG2 torque Tm2 is limited, that is, lowered, the driving force [N] that meets the driver's request is output.

  As described above, the vehicle control apparatus 10 according to the present embodiment has the MG2 torque Tm2 limited when the MG2 temperature K reaches the temperature threshold Kth [° C.] during reverse charging travel. Charge reverse running control is executed to increase the engine speed Ne while maintaining the engine power Pe so that the power output to the ring gear shaft 32a is increased by the limit of the MG2 torque Tm2.

  For this reason, even when the MG2 torque Tm2 is limited when performing reverse charging, the engine torque Te output from the engine 2 by increasing the engine speed Ne acts on the ring gear shaft 32a. The forward torque can be reduced. Thereby, the power output to the ring gear shaft 32a can be increased by the limit of the MG2 torque Tm2.

  Therefore, the vehicle control apparatus 10 according to the present embodiment can perform reverse charging traveling with a driving force that meets the driver's request, and can prevent the driver from feeling uncomfortable due to insufficient driving force. .

  Moreover, the vehicle control apparatus 10 according to the present embodiment increases the increase amount of the engine speed Ne as the MG2 temperature K becomes higher in the charge reverse travel control. That is, when the limit amount of the MG2 torque Tm2 increases as the MG2 temperature K increases, the increase amount of the engine speed Ne is increased in accordance with the increase of the limit amount.

  As a result, the amount of decrease in the forward torque acting on the ring gear shaft 32a of the engine torque Te output from the engine 2 can be increased as the limit amount of the MG2 torque Tm2 increases. Therefore, by appropriately changing the amount of decrease in the forward torque acting on the ring gear shaft 32a in accordance with the change in the limit amount of the MG2 torque Tm2, even if the limit amount of the MG2 torque Tm2 changes, the driver's request It is possible to carry out reverse charging with a driving force suitable for.

  Further, the vehicle control apparatus 10 according to the present embodiment increases the amount of increase in the engine speed Ne as the accelerator opening Acc is larger in the charge reverse travel control. As a result, the charging reverse traveling can be performed with the driving force corresponding to the accelerator opening degree Acc requested by the driver.

  Furthermore, the vehicle control apparatus 10 according to the present embodiment sets the target engine speed Net based on the accelerator opening Acc and the MG2 temperature K when the charge reverse travel control is executed, and the actual engine speed Ne is The engine 2 and the motor generator MG1 are controlled so as to achieve the target engine speed Net. Thereby, even if the MG2 torque Tm2 is limited as the MG2 temperature K increases, the reverse charging traveling can be performed with the driving force corresponding to the accelerator opening Acc requested by the driver.

  As described above, the vehicle control device according to the present invention can perform reverse traveling with a driving force that meets the driver's request, and can prevent the driver from feeling uncomfortable due to insufficient driving force. This is useful for a vehicle control device used in a hybrid vehicle.

DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle (vehicle), 2 ... Engine (internal combustion engine), 3 ... Power distribution integration mechanism (planetary gear mechanism), 8 ... Accelerator pedal, 9 ... Shift lever, 10 ... Control device for vehicles, 27 ... Crankshaft ( Output shaft), 32a ... Ring gear shaft (drive shaft), 36 ... Rotating shaft, 63a, 63b ... Drive wheel, 80 ... Battery (power storage means), 87 ... Motor temperature sensor (motor temperature detection means), 100 ... HVECU (control) Means), 102 ... Accelerator pedal position sensor (accelerator opening detection means), 103 ... Vehicle speed sensor, 104 ... Shift position sensor, 200 ... Engine ECU, 300 ... Motor ECU, 400 ... Battery ECU, MG1 ... Motor generator (generator) ), MG2 ... Motor generator (electric motor)

Claims (4)

A planet in which three rotating elements are connected to three axes of an internal combustion engine, a generator capable of inputting / outputting power, an output shaft of the internal combustion engine, a rotating shaft of the generator, and a driving shaft connected to driving wheels. A vehicle control device applied to a vehicle including a gear mechanism, an electric motor capable of inputting / outputting power to / from the drive shaft, and a power storage means for exchanging electric power with the generator and the electric motor,
Motor temperature detecting means for detecting the temperature of the motor;
The motor torque output from the motor when the temperature of the motor reaches a predetermined temperature when reverse running while charging the power storage means using a part of the power output from the internal combustion engine Is limited, the charging to increase the engine speed of the internal combustion engine while maintaining the engine output of the internal combustion engine so that the power output to the drive shaft is increased by the limit of the motor torque. And a control means for executing reverse running control.   2. The vehicle according to claim 1, wherein the control unit increases the amount of increase in the engine speed as the temperature of the electric motor detected by the electric motor temperature detection unit in the reverse charging traveling control increases. Control device. Accelerator opening detection means for detecting the accelerator opening of the vehicle,
3. The control device according to claim 1, wherein the control means increases the amount of increase in the engine speed as the accelerator opening detected by the accelerator opening detection means in the charging reverse travel control increases. The vehicle control device described in 1.   The control means determines a target engine speed based on the accelerator opening detected by the accelerator opening detection means and the temperature of the electric motor detected by the electric motor temperature detection means during execution of the reverse charging traveling control. 4. The vehicle according to claim 1, wherein the internal combustion engine and the generator are controlled so that the engine speed is set to the target engine speed. 5. Control device.

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