JP2012062027A - Vehicle control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fully demand to a driver, switching from an EV travel mode.SOLUTION: A vehicle control system includes: a travel mode selection device which makes a driver select manually an engine travel mode using power of an engine 10, an EV travel mode using power of a motor/generator 20, or a hybrid travel mode using power of both the engine 10 and the motor/generator 20; and a hybrid ECU 100 and a motor/generator ECU 102 which set the output characteristic of the motor/generator 20 according to vehicle speed when the driver selects the EV travel mode by the travel mode selecting device, and suppress or prohibit output from the motor/generator 20 when the efficiency of operating the engine 10 is superior to the motor/generator 20.

Description

  The present invention includes a mechanical power source powered by mechanical energy and an electrical power source powered by mechanical energy converted from electrical energy, and includes an engine traveling mode using the mechanical power source and an EV using the electrical power source. The present invention relates to a vehicle control system for manually switching between a traveling mode and a hybrid traveling mode using a mechanical power source and an electric power source.

  Conventionally, a vehicle including a mechanical power source and an electric power source as a power source is known. For example, in Patent Document 1 below, an optimal torque distribution ratio is set by taking advantage of the characteristics of the engine (mechanical power source) and motor (electric power source) with respect to the driver's driving intention (rate of change in required torque). A technique for optimally controlling the engine and the motor with the torque distribution ratio is disclosed. Patent Document 2 below discloses a technique in which a hybrid vehicle equipped with an automatic manual transmission is started by a motor and is driven by an engine at a predetermined vehicle speed or higher.

JP 2006-050877 A JP 2000-272360 A

  By the way, a hybrid vehicle in which the vehicle side automatically selects a travel mode such as an engine travel mode (in other words, a power source) is widely known. On the other hand, in a hybrid vehicle, it is also conceivable that the driving mode is left to the driver. However, in this type of hybrid vehicle, it is necessary for the driver to select a driving mode with a power source with good driving efficiency based on the current or future driving conditions such as the vehicle speed. It is difficult as a real problem to leave it to a person.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vehicle control system that can improve the disadvantages of the conventional example and can travel in a travel mode using a power source with good driving efficiency.

  In order to achieve the above object, the present invention generates an engine driving mode using the power of a mechanical power source that generates mechanical driving force using mechanical energy, and generates driving force using mechanical energy converted from electric energy. A driving mode selection device that allows a driver to manually select an EV driving mode using the power of an electric power source or a hybrid driving mode using the power of both the mechanical power source and the electric power source; When the output characteristics of the electric power source are set according to the vehicle speed when the EV driving mode is selected by the driving mode selection device, and the operating efficiency of the mechanical power source is superior to the electric power source And an electric power source control device that suppresses or prohibits the output from the electric power source.

  Here, the electric power source control device may change the output characteristic of the electric power source from the output characteristic at the time of selecting the EV driving mode according to the vehicle speed changed during the driving in the EV driving mode. desirable.

  Further, it is desirable that the electric power source control device changes the output characteristic at the intersection of the output of the electric power source in each of the output characteristics.

  When the vehicle control system according to the present invention is selected by the driver to perform EV travel, if it is found that the mechanical power source has better driving efficiency and better fuel efficiency than the electric power source, the electric power By suppressing or prohibiting the output from the source, it is difficult to match the driver's accelerator operation with the movement of the vehicle. In this control system, this makes the driver feel uncomfortable and prompts the switching operation from the EV travel mode to the engine travel mode or the hybrid travel mode. Therefore, since the possibility that the driver switches from the EV traveling mode to the engine traveling mode or the hybrid traveling mode is increased, this control system can cause the vehicle to travel in a traveling mode using a mechanical power source with good driving efficiency. .

FIG. 1 is a diagram illustrating an example of a hybrid vehicle to which a vehicle control system according to the present invention is applied. FIG. 2 is a diagram illustrating an example of the travel mode selection device when the neutral state is selected. FIG. 3 is a diagram illustrating an example of the travel mode selection device when the EV travel mode is selected. FIG. 4 is a diagram showing an example of an output characteristic map of the motor / generator in the EV traveling mode at the time of starting (at the time of low vehicle speed). FIG. 5 is a diagram showing an example of an output characteristic map of the motor / generator in the EV traveling mode at the middle vehicle speed. FIG. 6 is a diagram illustrating an example of switching from an output characteristic map at medium vehicle speed to an output characteristic map at start (at low vehicle speed). FIG. 7 is a diagram for explaining another example of switching from the output characteristic map at medium vehicle speed to the output characteristic map at start (at low vehicle speed).

  Embodiments of a vehicle control system according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

[Example]
An embodiment of a vehicle control system according to the present invention will be described with reference to FIGS.

  The vehicle to which the control system according to the present invention is applied includes a mechanical power source powered by mechanical energy and an electrical power source powered by mechanical energy converted from electrical energy, and uses only the power of the mechanical power source. The driver can manually switch between the engine driving mode, the EV driving mode using only the power of the electric power source, and the hybrid driving mode using the power of both the mechanical power source and the electric power source. It is a hybrid vehicle.

  First, an example of this hybrid vehicle will be described with reference to FIG. Reference numeral 1 in FIG. 1 indicates a hybrid vehicle of the present embodiment.

  The hybrid vehicle 1 includes an engine 10 that outputs mechanical power (engine torque) from an output shaft (crankshaft) 11 as a mechanical power source. The engine 10 may be an internal combustion engine, an external combustion engine, or the like. The operation of the engine 10 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 101. The engine 10 is provided with a starter motor 12 that is driven and controlled by the engine ECU 101 at the time of starting. Here, an engine control device (mechanical power source control device) is configured by the engine ECU 101 and functions related to engine control of the hybrid ECU 100 described later.

  Further, the hybrid vehicle 1 includes a motor, a generator capable of powering driving, or a motor / generator capable of driving both powering and regeneration as an electric power source. Here, the motor / generator 20 will be described as an example. The motor / generator 20 is configured, for example, as a permanent magnet AC synchronous motor, and its operation is controlled by a motor / generator electronic control device (hereinafter referred to as “motor / generator ECU”) 102. . Here, a motor / generator control device (electric power source control device) is configured by the motor / generator ECU 102 and functions related to motor / generator control of the hybrid ECU 100 described later. During power running, it functions as a motor (electric motor), converts electrical energy supplied via the secondary battery 25 and the inverter 26 into mechanical energy, and outputs mechanical power (motor power running torque) from the rotating shaft 21. To do. On the other hand, at the time of regenerative driving, it functions as a generator (generator) and converts mechanical energy into electrical energy when mechanical power (motor regenerative torque) is input from the rotary shaft 21, and power is supplied via the inverter 26. Is stored in the secondary battery 25.

  The hybrid vehicle 1 is provided with a battery monitoring unit 27 that detects a state of charge (SOC) of the secondary battery 25. The battery monitoring unit 27 transmits to the motor / generator ECU 102 a signal related to the detected state of charge of the secondary battery 25 (in other words, a signal related to the amount of state of charge (SOC amount)). The motor / generator ECU 102 determines the charging state of the secondary battery 25 based on the signal, and determines whether or not the secondary battery 25 needs to be charged.

  The hybrid vehicle 1 includes a power transmission device including a stepped manual transmission 30 and the like. The power transmission device transmits the power of the engine 10 and the motor / generator 20 (engine torque and motor power running torque) to the driving wheels WL and WR as a driving force.

  The manual transmission 30 includes an input shaft 41 to which engine torque is input, an output shaft 42 that is disposed in parallel to the input shaft 41 at an interval and outputs torque to the drive wheels WL and WR, Is provided.

  Engine torque is input to the input shaft 41 via the clutch 50. The clutch 50 is in an engaged state in which the output shaft 11 and the input shaft 41 of the engine 10 are engaged, and in a released state (not engaged) in which the output shaft 11 and the input shaft 41 are released (not engaged) from the engaged state. For example, a friction clutch device configured to be able to switch between the engaged state and the engaged state. The engaged state referred to here is a state where torque can be transmitted between the output shaft 11 and the input shaft 41, and the released state (non-engaged state) refers to the output shaft 11 and This is a state where torque cannot be transmitted to the input shaft 41. In the clutch 50, the switching operation between the engaged state and the released state is mechanically performed through a link mechanism, a wire, or the like according to the operation of the clutch pedal 51 by the driver.

  In this embodiment, the motor / generator 20 is connected to the output shaft 42 via a gear pair 60 as an EV gear. The gear pair 60 includes a first gear 61 and a second gear 62 that are in mesh with each other. The first gear 61 is attached so as to rotate integrally with the rotating shaft 21 of the motor / generator 20. On the other hand, the second gear 62 has a larger diameter than the first gear 61 and is attached to the output shaft 42 of the manual transmission 30 so as to rotate integrally. As a result, the gear pair 60 operates as a reduction gear when torque is input from the rotating shaft 21 side of the motor / generator 20, while rotating torque is input from the output shaft 42 side of the manual transmission 30. Operates as a speed increasing device. Accordingly, when the motor / generator 20 is driven by power running, the motor power running torque is transmitted to the manual transmission 30 via the gear pair 60 functioning as a reduction gear. In contrast, when the motor / generator 20 is regeneratively driven, the output torque from the output shaft 42 of the manual transmission 30 is transmitted to the rotor of the motor / generator 20 via the gear pair 60 that functions as a speed increasing device. Is done. Here, the gear pair 60 is located at any position on the shift gauge 81b, that is, a shift lever 81a, which will be described later, that is, at a shift position 1 to 4, R, an EV travel mode selection position EV, or a neutral position. Assume that they are engaged. The motor / generator 20 may directly connect the rotary shaft 21 to the output shaft 42 of the manual transmission 30 without using the gear pair 60.

  Further, the manual transmission 30 exemplified here has four forward speeds and one reverse speed, and the first speed gear stage 31, the second speed gear stage 32, the second speed stage as the forward speed stages. A third gear stage 33 and a fourth gear stage 34 are provided, and a reverse gear stage 39 is provided as a reverse gear stage. The forward gear is configured such that the gear ratio decreases in the order of the first speed gear stage 31, the second speed gear stage 32, the third speed gear stage 33, and the fourth speed gear stage 34. Note that the manual transmission 30 in FIG. 1 is a simple description of the configuration, and the arrangement of each gear stage is not necessarily in the form of FIG.

  In the power transmission device of the present embodiment, the engine torque input to the input shaft 41 is set to any one of the gear positions (gear stages 31 to 34, 39) by engaging the clutch 50. And is transmitted to the output shaft 42. In this power transmission device, the motor power running torque is transmitted to the output shaft 42 via the gear pair 60. In this power transmission device, the torque output from the output shaft 42 is decelerated by the final reduction mechanism 71 and transmitted to the driving wheels WL and WR as a driving force via the differential mechanism 72.

  Here, the first speed gear stage 31 is constituted by a gear pair of a first speed drive gear 31a and a first speed driven gear 31b that are in mesh with each other. The first speed drive gear 31 a is disposed on the input shaft 41, while the first speed driven gear 31 b is disposed on the output shaft 42. Also for the second speed gear stage 32 to the fourth speed gear stage 34, the second speed drive gear 32a to the fourth speed drive gear 34a and the second speed driven gear 32b to the fourth speed driven similar to the first speed gear stage 31 are used. A gear 34b is provided.

  On the other hand, the reverse gear stage 39 includes a reverse drive gear 39a, a reverse driven gear 39b, and a reverse intermediate gear 39c. The reverse drive gear 39 a is disposed on the input shaft 41, and the reverse driven gear 39 b is disposed on the output shaft 42. The reverse intermediate gear 39c is in mesh with the reverse drive gear 39a and the reverse driven gear 39b, and is disposed on the rotation shaft 43.

  In the configuration of the manual transmission 30, one of the drive gears of each gear stage is disposed so as to rotate integrally with the input shaft 41, while the remaining drive gear is relative to the input shaft 41. Are arranged to rotate relative to each other. In addition, the driven gear of each shift stage is arranged so that any one of them is rotated integrally with the output shaft 42, while the rest is arranged so as to rotate relative to the output shaft 42. The

  The input shaft 41 and the output shaft 42 are provided with sleeves (not shown) that move in the axial direction in accordance with the driver's speed change operation. The sleeve on the input shaft 41 is disposed between the drive gears of the two shift stages that can rotate relative to the input shaft 41. On the other hand, the sleeve on the output shaft 42 is disposed between the driven gears of the two gears that can rotate relative to the output shaft 42. The sleeve moves in the axial direction via a link mechanism or a fork (not shown) connected to the speed change operation device 81 when the driver operates the speed change operation device 81. Then, the moved sleeve rotates the drive gear and the driven gear, which can be relatively rotated, located in the moved direction, together with the input shaft 41 and the output shaft 42. In the manual transmission 30, the sleeve moves in a direction corresponding to the speed change operation of the driver's speed change operation device 81, thereby switching to a gear position according to the speed change operation or a neutral state (that is, the input shaft 41. And a state in which torque cannot be transmitted between the output shaft 42 and the output shaft 42).

  As shown in FIG. 2, the shift operation device 81 includes a shift lever 81a used when the driver performs a shift operation, a so-called shift gauge 81b for guiding the shift lever 81a for each shift stage, the link mechanism, It has a fork. FIG. 2 shows the position of the shift lever 81a when the manual transmission 30 is operated to the neutral state. Note that “1-4” and “R” on the shift gauge 81b in FIG. 2 indicate the shift positions (select positions) of the first gear stage 31 to the fourth gear stage 34 and the reverse gear stage 39, respectively. Show.

  In the hybrid vehicle 1, at least an engine travel mode, an EV travel mode, and a hybrid travel mode are prepared as travel modes.

  In the hybrid vehicle 1, the engine travel mode or the hybrid travel mode is selected when the shift lever 81a is located in any one of the shift positions 1 to 4 and R on the shift gauge 81b.

  On the other hand, the hybrid vehicle 1 uses an EV travel mode switching device that is operated by the driver when the EV travel mode is selected. Here, the shift operation device 81 is provided with the function as the EV traveling mode switching device. That is, the shift operation device 81 of the present embodiment not only allows the driver to switch the gear position of the manual transmission 30, but also functions as an EV travel mode switching device when the driver switches to the EV travel mode. Yes. For example, this shift operation device 81 is provided with an EV travel mode selection position EV on the shift gauge 81b, which is the select position of the shift lever 81a similar to the shift positions 1 to 4 and R, and for switching to the EV travel mode. Yes. In the hybrid vehicle 1 of the present embodiment, when the shift lever 81a is operated to the EV travel mode selection position EV as shown in FIG. 3, the manual transmission 30 is in a neutral state by a sleeve or the like, and the travel mode is EV travel mode is set.

  The shift operation device 81 is provided with an EV travel mode selection position detector 82 that detects whether or not the shift lever 81a is located at the EV travel mode selection position EV. The EV travel mode selection position detector 82 is, for example, a position information detection sensor that can detect that the shift lever 81a is at the EV travel mode selection position EV as shown in FIG. The detection signal of the EV traveling mode selection position detection unit 82 is transmitted to an electronic control unit (hereinafter referred to as “hybrid ECU”) 100 that comprehensively controls the operation of the entire vehicle.

  The hybrid ECU 100 can exchange information such as detection signals of various sensors and control commands between the engine ECU 101 and the motor / generator ECU 102. In this embodiment, at least the hybrid ECU 100, the engine ECU 101, and the motor / generator ECU 102 are constituent requirements of the vehicle control system.

  Further, the shift operation device 81 detects which shift position 1 to 4 or R of the shift lever 81a is on the shift gauge 81b, that is, which shift stage the driver has selected. Part 83 is provided. The shift position detection unit 83 may use, for example, a position information detection sensor that can detect which shift positions 1 to 4 and R the shift lever 81a is at. The detection signal is sent to the hybrid ECU 100. The hybrid ECU 100 determines the speed selected by the driver and the current speed based on the detection signal. Here, for the sake of convenience, the shift position detection unit 83 is illustrated as being different from the EV travel mode selection position detection unit 82, but these are replaced with a shift lever position detection unit (not shown) integrated into one. May be. Here, the hybrid ECU 100 may estimate the current shift speed from the engine torque, the wheel speed, or the like using a known technique known in this technical field.

  When the shift lever 81a is operated to the shift positions 1 to 4 and R, the hybrid ECU 100 selects either the engine travel mode or the hybrid travel mode. For example, the hybrid ECU 100 includes a set driver's drive request (required driving force), information on the state of charge of the secondary battery 25 (SOC amount) sent from the motor / generator ECU 102, and information on the vehicle running state (illustrated). On the basis of the vehicle lateral acceleration detected by the vehicle lateral acceleration detection device and information on the slip state of the drive wheels WL and WR detected by the wheel slip detection device), the engine travel mode and the hybrid travel mode are switched.

  When the engine running mode is selected, the hybrid ECU 100 sends a control command to the engine ECU 101 and the motor / generator ECU 102 so as to generate the required driving force only with the engine torque. In this case, as a control command to the engine ECU 101, for example, information on the engine torque that satisfies the required driving force at the current shift stage or the shift stage after the shift operation is transmitted. As a result, the engine ECU 101 controls the fuel injection amount of the engine 10 so as to generate the engine torque. On the other hand, a control command is sent to the motor / generator ECU 102 so that the motor / generator 20 does not operate as a motor or a generator.

  On the other hand, when the hybrid travel mode is selected, the hybrid ECU 100 causes the engine ECU 101 and the motor / generator ECU 102 to generate the required driving force based on the engine torque and the output of the motor / generator 20 as a motor or a generator. Send a control command. In this case, when both the engine torque and the motor power running torque are used, as a control command to the engine ECU 101 and the motor / generator ECU 102, for example, an engine torque that satisfies the required driving force at the current shift stage or the shift stage after the shift operation. And motor power running torque information is transmitted to each. Thereby, the engine ECU 101 controls the engine 10 so as to generate the engine torque, and the motor / generator ECU 102 controls the power supply amount to the motor / generator 20 so as to generate the motor power running torque. When the motor / generator 20 performs power regeneration, a control command is sent to the motor / generator ECU 102 to operate the motor / generator 20 as a generator. At that time, for example, information on the engine torque increased by the amount of the motor regeneration torque is sent to the engine ECU 101.

  When the shift lever 81a is operated to the EV travel mode selection position EV, the hybrid ECU 100 sends a control command to the engine ECU 101 and the motor / generator ECU 102 so that the required driving force is generated only by the motor power running torque. In this case, information on the motor power running torque that satisfies the required driving force is transmitted as a control command to the motor / generator ECU 102. If the engine 10 is operating when the manual transmission 30 is in the neutral state, the fuel efficiency is deteriorated. Therefore, a control command for stopping the operation of the engine 10 is sent to the engine ECU 101 in order to improve the fuel efficiency. Further, in this EV travel mode, control is performed so that regenerative braking can be performed on the motor / generator ECU 102 when the driver removes his or her foot from the accelerator pedal 91 or when a request for deceleration of the hybrid vehicle 1 is made by a brake operation or the like. A command may be sent.

  In the hybrid vehicle 1 of the present embodiment, the switching between the engine travel mode or the hybrid travel mode and the EV travel mode is executed in response to the operation of the clutch 50 and the operation of the speed change operation device 81 by the driver. That is, it can be said that the clutch 50, the clutch pedal 51, and the speed change operation device 81 of this embodiment are travel mode selection devices for allowing the driver to manually select the travel mode. When the driver switches from the engine travel mode or the hybrid travel mode to the EV travel mode, the driver releases the clutch 50, operates the shift lever 81a from the shift position 1 to 4 to the EV travel mode selection position EV, and engages the clutch 50. Combine operations in sequence. At this time, the detection signal received by the hybrid ECU 100 changes from the detection signal of the shift position detection unit 83 to the detection signal of the EV travel mode selection position detection unit 82. On the other hand, when switching from the EV travel mode to the engine travel mode or the hybrid travel mode, the clutch 50 is released, the EV travel mode selection position EV is operated to the shift positions 81 to 4 of the shift lever 81a, and the clutch 50 is engaged. Joint operations are performed in order. At this time, the detection signal received by the hybrid ECU 100 changes from the detection signal of the EV travel mode selection position detection unit 82 to the detection signal of the shift position detection unit 83.

  Incidentally, the engine 10 and the motor / generator 20 each have a vehicle speed range with good driving efficiency suitable for improving fuel efficiency, although it depends on the specifications. For this reason, in order to improve fuel efficiency, it is preferable to drive using a power source with good driving efficiency. In the hybrid vehicle 1, when the operating efficiency of the engine 10 and the operating efficiency of the motor / generator 20 are compared for each vehicle speed, the operating efficiency of the motor / generator 20 is higher than that of the engine 10 at the time of starting, that is, at a low vehicle speed. Is better. Further, the motor / generator 20 has a driving efficiency higher than that of the engine 10 even during steady running in a low vehicle speed range (for example, a vehicle speed range when running on a general road within the legal speed range), that is, at a medium vehicle speed. Are better. Therefore, at low vehicle speeds and medium vehicle speeds, the fuel consumption performance is higher than when the engine 10 is driven by running by using the output of the motor / generator 20. On the other hand, in other vehicle speed ranges, that is, at high vehicle speeds (during high speed driving), the operating efficiency of the engine 10 is superior to the motor / generator 20, and by using the output of the engine 10 to drive Fuel efficiency is improved.

  Therefore, in this control system, when the EV traveling mode is selected, if the vehicle speed at the time of selection is a vehicle speed range in which the motor / generator 20 is more excellent in driving efficiency than the engine 10, it is determined by the driver. The vehicle is driven using the power of the motor / generator 20 as desired. On the other hand, in this control system, if the vehicle speed at the time of selection is a vehicle speed range in which the driving efficiency of the engine 10 is superior to that of the motor / generator 20, the driver is instructed to improve fuel efficiency. The user is prompted to switch from the EV travel mode to the engine travel mode using the power of the engine 10 or the hybrid travel mode.

  For example, the hybrid vehicle 1 is recommended to use the EV traveling mode at the time of starting, which tends to increase the fuel consumption of the engine 10. For this reason, this control system is provided with an output characteristic map (FIG. 4) of the motor / generator 20 in the EV traveling mode at the time of starting (at the time of low vehicle speed). The output characteristic map at the time of starting (at the time of low vehicle speed) generates the maximum motor power running torque Tmg within the range not exceeding the output upper limit value of the motor power running torque Tmg when the rotation speed Nmg (vehicle speed V) is the lowest, The output characteristic is that the motor power running torque Tmg is gradually reduced as the rotational speed Nmg (vehicle speed V) increases.

  Here, the motor / generator 20 can output the motor power running torque Tmg to the maximum output upper limit value until the rotational speed Nmg (vehicle speed V) exceeds a certain rotational speed Nmg1 (vehicle speed V1). When Nmg1 (vehicle speed V1) is exceeded, the output upper limit value of the motor power running torque Tmg gradually decreases. The output upper limit varies depending on the specifications of the motor / generator 20. In the motor / generator 20, a time lower than the rotational speed Nmg1 (vehicle speed V1) is a low vehicle speed corresponding to a start.

  In this output characteristic map, at the end of the starting operation (low vehicle speed), specifically, the motor power running is set so that the rotation speed Nmg (vehicle speed V) becomes 0 around the predetermined rotation speed Nmg1 (predetermined vehicle speed V1). Torque Tmg is reduced. That is, in this output characteristic map, the output from the motor / generator 20 is prohibited when the start operation is finished. In this output characteristic map, the maximum motor power running torque Tmg that can improve the fuel efficiency is set.

  In the control system in this case, when the vehicle speed V (detected by the vehicle speed detection device 95 such as a vehicle speed sensor) when the EV travel mode is selected is in the low vehicle speed range (Nmg <Nmg1, V <V1), The output characteristic map at the time of low vehicle speed is read, and the motor / generator torque Tmg corresponding to the output characteristic map is output to the motor / generator 20. For example, the hybrid ECU 100 sends a command to the motor / generator ECU 102 to control the motor / generator 20 with the output characteristic map.

  When the EV driving mode is selected for starting, the motor power running torque Tmg corresponding to the output characteristic map at the time of starting (at low vehicle speed) is output in accordance with the driver's accelerator operation, and the hybrid vehicle 1 starts to start. . Since the hybrid vehicle 1 at this time outputs only the motor power running torque Tmg corresponding to the output characteristic map in the low vehicle speed range, it is possible to perform EV traveling with excellent fuel efficiency.

  Here, in the output characteristic map, the output of the motor power running torque Tmg is prohibited when the low vehicle speed range ends (that is, when the start ends). Therefore, in this case, the hybrid vehicle 1 starts to decelerate regardless of the driver's acceleration request, so that the driver feels uncomfortable. Generally, a driver of a vehicle equipped with the manual transmission 30 performs a downshift operation by placing a hand on the shift lever 81a when a desired acceleration cannot be obtained in response to his / her own acceleration request. In other words, in this control system, by prohibiting the output of the motor power running torque Tmg, the possibility that the driver is put on the shift lever 81a is increased. Therefore, this control system prohibits the output from the motor / generator 20 to prompt the driver to switch from the EV travel mode to the engine travel mode or the hybrid travel mode. In that case, the following alarm may be output together with the prohibition of the output from the motor / generator 20.

  Before the hybrid ECU 100 prohibits the output from the motor / generator 20, at the time of the vehicle speed V at which the motor power running torque Tmg is still output, the hybrid ECU 100 changes the engine travel mode or the hybrid travel mode from the EV travel mode to the driver. You may be prompted to switch to. For example, at that time, an alarm is output from the acoustic device 96 in the vehicle interior, or a message or the like is displayed on the display device 97 in the vehicle interior to notify the driver of the switching of the travel mode.

  If the driver performs a driving mode switching operation due to the uncomfortable feeling or warning, the hybrid ECU 100 switches to driving in the engine driving mode or the hybrid driving mode.

  In the hybrid vehicle 1, the motor / generator 20 is superior in driving efficiency to the engine 10 even in the middle vehicle speed range. For this reason, an output characteristic map (FIG. 5) of the motor / generator 20 in the EV traveling mode at medium vehicle speed is also prepared in this control system. At the middle vehicle speed, the output upper limit value of the motor power running torque Tmg is lower than that at the start, and a driving force as large as that at the start is not required. In addition to the vehicle speed range in which the driving efficiency of the motor / generator 20 is superior to that of the engine 10, the output characteristic map at the medium vehicle speed includes the operability of the driver at the medium vehicle speed in the EV traveling mode (for example, an accelerator pedal). The vehicle speed range for the margin is taken into account in consideration of the response to the depression of 91). Here, the motor power running torque Tmg gradually rises from a region where the rotational speed Nmg (vehicle speed V) is lower than the predetermined rotational speed Nmg1 (predetermined vehicle speed V1), and is output from around the predetermined rotational speed Nmg1 (predetermined vehicle speed V1). The motor power running torque Tmg is made substantially constant within a range not exceeding the upper limit value, and the output characteristic map of the output characteristics is such that the motor power running torque Tmg is gradually reduced to 0 as the middle vehicle speed comes to an end. That is, this output characteristic map can output the motor power running torque Tmg not only in the middle vehicle speed range but also in a part of the low vehicle speed range and the high vehicle speed range. Also in this output characteristic map, the maximum motor power running torque Tmg that can improve the fuel efficiency is set. This output characteristic map is used when the vehicle speed V when the EV traveling mode is selected is equal to or higher than the middle vehicle speed range (Nmg ≧ Nmg1, V ≧ V1).

  In the control system in this case, when the vehicle speed V when the EV traveling mode is selected is in the middle vehicle speed range, the output characteristic map at the middle vehicle speed is read, and the motor power running torque Tmg corresponding to the output characteristic map is read by the motor. / The generator 20 is made to output. Therefore, since this hybrid vehicle 1 outputs only the motor power running torque Tmg corresponding to the output characteristic map in the middle vehicle speed range, it is possible to perform EV traveling with excellent fuel efficiency.

  As described above, this control system limits the output possible range of the motor / generator 20 when the EV traveling mode is selected to a vehicle speed range with good driving efficiency, and when the vehicle speed V deviates from or deviates from the vehicle speed range. The driver is prompted to switch to the engine travel mode or the hybrid travel mode. For this reason, the hybrid vehicle 1 can travel by EV using the power of the motor / generator 20 that has better fuel efficiency than the engine 10 in the vehicle speed range where the driving efficiency of the motor / generator 20 is better than that of the engine 10. If the vehicle 10 is in a vehicle speed range where the driving efficiency of the engine 10 is better, the vehicle can travel using the power of the engine 10 that has better fuel efficiency than the motor / generator 20. Therefore, the hybrid vehicle 1 can perform fuel consumption traveling in various vehicle speed ranges. Further, since this control system places such a restriction on the output possible range of the motor / generator 20 when the EV traveling mode is selected, that is, when the vehicle speed V deviates from the vehicle speed range where the driving efficiency is good. Since the output from the motor / generator 20 is prohibited, the frequency of use of the motor / generator 20 can be suppressed, and a decrease in the remaining capacity (SOC amount) of the secondary battery 25 can be suppressed.

  In this example, when the switching operation from the EV traveling mode is not performed on the high vehicle speed range side of the output characteristic map at the start (at low vehicle speed) and the output characteristic map at medium vehicle speed, the motor / generator 20 It is also conceivable to output motor power running torque Tmg or the like corresponding to the driver's accelerator operation amount (detected by an accelerator operation amount detection device 92 such as an accelerator opening sensor) without prohibiting the output. However, such use of the motor / generator 20 is not preferable because it reduces the remaining capacity (SOC amount) of the secondary battery 25. In addition, the use of the motor / generator 20 in the high vehicle speed range is not preferable because the fuel efficiency is also deteriorated. Therefore, it is better to avoid using the motor / generator 20 as much as possible, but there is a possibility that the operation is not performed even if the driving mode switching operation is prompted. If the driver decelerates and the driver does not want to decelerate, not only does the driver feel uncomfortable, but the drivability deteriorates. Therefore, it is preferable to output the motor power running torque Tmg having a magnitude smaller than that according to the driver's accelerator operation, in order to suppress the decrease in the SOC amount while suppressing the driver's uncomfortable feeling and the deterioration in drivability. The suppressed output from the motor / generator 20 suppresses the driver's uncomfortable feeling, drivability deterioration, and a decrease in the amount of SOC to some extent, while reducing the actual difference in the movement of the hybrid vehicle 1 with respect to the request according to the accelerator operation. Since the driver can sense it, this control system can further prompt the switching operation from the EV traveling mode while continuing the traveling.

  Here, on the low vehicle speed range side of the output characteristic map at the time of medium vehicle speed, the vehicle speed V is the output prohibited region (Tmg) of the motor / generator 20 if it is not operated despite prompting the switching operation from the EV travel mode. = 0). Since the hybrid vehicle 1 cannot generate driving force even if the driver tries to accelerate under such circumstances, the hybrid vehicle 1 continues to decelerate without being able to accelerate. This is because the output characteristic map used in the EV travel mode is selected based on the vehicle speed V when the EV travel mode is selected, and cannot be handled when the vehicle speed V falls to the output prohibited area of the motor / generator 20. Because. In this control system, in order to avoid such a situation, the output characteristic map at the middle vehicle speed is switched to the output characteristic map at the start (at the low vehicle speed).

  For example, in this control system, at the intersection of the motor power running torque Tmg in the output characteristic map at the time of starting (at the time of low vehicle speed) and at the time of medium vehicle speed, from the output characteristic map at the time of medium vehicle speed, at the time of starting (at the time of low vehicle speed) Switch to the output characteristics map. The motor power running torque Tmg and the vehicle speed V at the intersection are obtained in advance. Hereinafter, the vehicle speed V at the intersection is referred to as “characteristic change vehicle speed Vch”.

  When the EV traveling mode is selected during traveling in the middle vehicle speed range, as shown in FIG. 6, an output characteristic map at the middle vehicle speed is selected. If the driver removes his / her foot from the accelerator pedal 91 during the EV traveling, the hybrid vehicle 1 starts decelerating and continues as it is, so that output on the low vehicle speed side of the motor / generator 20 on the map is prohibited. The area approaches. The hybrid ECU 100 determines whether or not the vehicle speed V has dropped to the characteristic change vehicle speed Vch while the vehicle speed V is decreasing. If the vehicle speed V has not reached the characteristic change vehicle speed Vch, the hybrid ECU 100 maintains the current output characteristic map at the medium vehicle speed. Continue EV driving. Then, when the vehicle speed V drops to the characteristic change vehicle speed Vch, the hybrid ECU 100 switches from the output characteristic map at the medium vehicle speed to the output characteristic map at the start (at the low vehicle speed). Therefore, when the accelerator pedal 91 is subsequently stepped on, the hybrid vehicle 1 can be accelerated with the motor power running torque Tmg based on the output characteristic map at the time of starting (at low vehicle speed).

  In this way, by changing the output characteristic map at the intersection characteristic change vehicle speed Vch in each output characteristic map, fluctuations in the motor power running torque Tmg associated with the switching can be eliminated. Therefore, this control system does not cause fluctuations in driving force due to switching of the output characteristic map, and therefore does not give the driver a sense of incongruity such as a pitching change. Further, this control system can generate the maximum motor power running torque Tmg within the range in which the fuel consumption performance can be improved before and after the switching of the output characteristic map, and the fuel consumption running is possible even after the switching.

  In this case, if acceleration is continued using the output characteristic map at the time of start (at the time of low vehicle speed), the vehicle speed V increases to the output prohibited area of the motor / generator 20 of this output characteristic map. For this reason, as described above, this control system prompts the switching operation from the EV traveling mode.

  The output characteristic map may be switched as follows.

  In the control system in this case, as shown in FIG. 7, EV traveling using the currently selected output characteristic map at medium vehicle speed to the end (that is, until the output of the motor power running torque Tmg is prohibited) is performed. When the vehicle speed (characteristic change vehicle speed Vch) at which the motor power running torque Tmg cannot be output in the output characteristic map is reached, the output characteristic map is switched to the output characteristic map at the time of starting (at low vehicle speed). Therefore, also in this case, when the accelerator pedal 91 is subsequently stepped on, the hybrid vehicle 1 can be accelerated by the motor power running torque Tmg based on the output characteristic map at the time of starting (at low vehicle speed).

  As described above, in this case, the hysteresis until the output characteristic map is switched is larger than in the previous example, and the output characteristic map is not switched unless the vehicle speed V is lowered to such an extent that it can be determined that the vehicle is starting. The driver can easily recognize that the output characteristic map has been switched.

  Here, in the above example of switching of the output characteristic map, since switching is performed at the intersection of the motor power running torque Tmg in each output characteristic map, the acceleration operation of the accelerator pedal 91 by the driver is performed at an early stage after the switching. The smaller the vehicle speed difference, the smaller the vehicle speed difference from the acceleration operation to the output prohibited region of the motor / generator 20 on the output characteristic map at the time of starting (at low vehicle speed). Therefore, at this time, the acceleration time according to the output characteristic map at the time of starting (at the time of low vehicle speed) is shortened. On the other hand, by using the output characteristic map at medium vehicle speed to the end and switching to the output characteristic map at start (at low vehicle speed), the vehicle speed difference can be widened, so at start (at low vehicle speed) ), The acceleration time by the output characteristic map becomes longer, and the acceleration performance can be improved.

  The two types of output characteristic map switching given here as examples show only switching from the output characteristic map at the medium vehicle speed to the output characteristic map at the start (at low vehicle speed). This is because if the reverse switching is performed, the usage time of the EV traveling mode may be prolonged, and the remaining capacity (SOC amount) of the secondary battery 25 may be significantly reduced. However, when it is required to suppress the driver's uncomfortable feeling or drivability deterioration even if he / she pays close attention to the decrease in the SOC amount described above, instead of suppressing the output from the motor / generator 20, at the time of starting (at low vehicle speed) The reverse switching from the output characteristic map of () to the output characteristic map at medium vehicle speed may be executed.

  As described above, the vehicle control system according to the present invention is useful for a technique that allows a vehicle to travel in a travel mode using a power source with good driving efficiency.

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 10 Engine 12 Starter motor 20 Motor / generator 25 Secondary battery 27 Battery monitoring unit 30 Manual transmission 50 Clutch 51 Clutch pedal 60 Gear pair (EV gear)
DESCRIPTION OF SYMBOLS 81 Shift operation device 81a Shift lever 81b Shift gauge 82 EV driving mode selection position detection part 83 Shift position detection part 100 Hybrid ECU
101 engine ECU
102 Motor / generator ECU
EV EV mode selection position

Claims (3)

Engine travel mode using the power of a mechanical power source that generates mechanical power using mechanical energy, and EV travel mode that uses the power of an electrical power source that generates mechanical power generated by converting mechanical energy Or a driving mode selection device that allows a driver to manually select a hybrid driving mode using the power of both the mechanical power source and the electric power source;
An output characteristic of the electric power source is set according to a vehicle speed when the driver selects the EV driving mode by the driving mode selection device, and the driving efficiency of the mechanical power source is superior to the electric power source. An electric power source control device that suppresses or prohibits output from the electric power source when
A vehicle control system comprising:   The electric power source control device changes an output characteristic of the electric power source from an output characteristic at the time of selecting the EV driving mode according to a vehicle speed changed during driving in the EV driving mode. The vehicle control system according to claim 1.   3. The vehicle control system according to claim 2, wherein the electric power source control device changes the output characteristic at an intersection of the output of the electric power source in each of the output characteristics.

Images