JP4345771B2 - Display device for hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle, and more particularly, to a technique for notifying an operating state of a power source in accordance with a driver's feeling.

  A hybrid equipped with an engine that operates with fuel combustion energy and an electric motor that operates with electric energy as a power source when the vehicle travels, and an automatic transmission is provided between the power source and drive wheels Vehicles are in practical use. In such a hybrid vehicle, for example, by using the engine and the electric motor properly according to the driving state, it is possible to reduce the fuel consumption amount and the exhaust gas amount while maintaining a predetermined traveling performance. Specifically, engines such as an engine running mode that runs using only the engine as a power source, a motor running mode that runs using only an electric motor as a power source, and an engine + motor running mode that runs using both the engine and the electric motor as power sources. And a plurality of operation modes with different operation states of the electric motor, and according to predetermined mode switching conditions such as a power source map using the operation state such as the vehicle speed (or the power source rotation speed) and the accelerator operation amount as parameters. It can be switched automatically.

  By the way, in such a hybrid vehicle, if only the vehicle speed and the engine speed are displayed as in an engine-driven vehicle using only the engine as a power source, for example, the engine speed is displayed in the motor travel mode (usually 0). ), There is not enough information to know the operating state and traveling state of the power source, and it does not necessarily satisfy the driver's requirements sufficiently.

  Japanese Laid-Open Patent Publication No. 10-129298 (Patent Document 1) discloses a hybrid vehicle having an engine and an electric motor as a power source. Disclosed is a hybrid vehicle that can accurately inform a driver of desired information. The hybrid vehicle disclosed in Patent Document 1 is a hybrid vehicle that includes an engine that operates with fuel combustion energy and an electric motor that operates with electric energy as a power source when the vehicle travels. The display unit displays at least one of the total power and torque that can be used. Furthermore, it has a display part which displays at least one of the power and torque of the output side of the power transmission device which is arrange | positioned between an engine and an electric motor, and a driving wheel and transmits motive power.

  In this hybrid vehicle, at least one of the total power and torque that can be used for driving the vehicle (including when it is actually used) is displayed, so the power and torque of the engine and electric motor are displayed separately. Compared with the case where it does, it can grasp | ascertain easily and correctly the operating state, driving | running | working state, etc. of the power source of the present vehicle. In particular, since the power and torque that can be used for vehicle driving are displayed, when a part of the engine output is consumed for charging control, the power and torque other than that are displayed. Therefore, it is significant as information when the vehicle is running or racing (when the accelerator is operated in a neutral state). In addition, since at least one of the power and torque on the output side of the power transmission device is displayed, the total power and torque used for actual vehicle travel are displayed, and the current vehicle travel state is displayed. It is meaningful in grasping. It should be noted that the rotational speed on the output side of the power transmission device substantially means the vehicle speed, and is usually already provided in the vehicle as a speedometer, and the traveling state of the vehicle is further enhanced in combination with this vehicle speed. It becomes possible to judge in detail.

  Furthermore, Japanese Patent Laying-Open No. 2005-35413 (Patent Document 2) discloses a vehicle display device that facilitates visual recognition regarding the traveling state of a vehicle having a plurality of power sources. This vehicle display device may be a value indicating the vehicle speed and a value indicating the vehicle output (the value of the vehicle output itself, or the torque of the engine or motor used to calculate the vehicle output). A display control unit for two-dimensionally displaying the value) on the screen.

According to this vehicle display device, the vehicle speed and output can be visually displayed together in one area. Therefore, the driver can instantly recognize the two pieces of information regarding the running state without moving the viewpoint, which contributes to improvement of driving safety. In addition, since the driver can visually recognize the acceleration feeling of traveling as information other than the bodily sensation, the driver can be provided with a comfortable driving environment in which the driver can fully experience the acceleration feeling.
JP-A-10-129298 JP 2005-35413 A

  However, as described above, the ratio of the total power and torque currently generated to the maximum total power and torque that can be used for running the vehicle is displayed, and the vehicle speed and output are displayed in two dimensions. Even so, it is difficult for a driver who is accustomed to a vehicle equipped only with a conventional engine to sensuously know the running state of the vehicle (how much output the vehicle is running). That is, in the engine, the engine output increases as the engine speed increases. For this reason, the driver is accustomed to sensuously grasping the output state of the engine, which is the power source of the vehicle, from the engine speed displayed on the tachometer provided on the instrument panel. . Even if such a driver is informed of the state of the vehicle by a display unique to the hybrid vehicle disclosed in the above-mentioned patent document, it is difficult to grasp the state of the vehicle sensuously.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a display device for a hybrid vehicle that can intuitively grasp the state of the vehicle in the hybrid vehicle. .

  A display device according to a first invention is a display device for a hybrid vehicle using an engine and a power source other than the engine as a travel source of the vehicle. This display device includes a calculation means for calculating the output of the traveling source, a conversion means for converting the calculated output into an equivalent rotational speed corresponding to the rotational speed of the engine, and an equivalent rotational speed for only the engine. Display means for displaying on the tachometer displaying the same unit as the engine tachometer provided in the vehicle as the travel source.

  According to the first aspect of the invention, for example, in a hybrid vehicle equipped with an engine and an electric motor as a running source of the vehicle, the output as the current hybrid system is calculated, and this is equivalent to the engine speed (here, equivalent (Including that there is a correlation). The converted equivalent rotational speed is displayed in the same manner as that in a vehicle having only the engine as a travel source (that is, the same unit as an engine speed meter (tachometer) provided in a vehicle having only the engine as a travel source). Display on the displayed tachometer), the driver can recognize the output of the vehicle with the same feeling as a vehicle equipped with only an engine. That is, it is easy for a driver who is used to a vehicle equipped with only an engine to recognize the state of the vehicle. As a result, the engine speed is displayed in the same manner as a vehicle that uses only the engine as a power source, so you are used to driving a vehicle equipped with only the engine, and you know the running state of the vehicle based on the engine speed. Even when the driver drives an unfamiliar hybrid vehicle, the traveling state of the vehicle can be grasped with the same engine speed with the same engine speed NE (EQ), so that the state of the vehicle can be intuitively grasped.

  In the display device according to the second invention, in addition to the configuration of the first invention, the power source other than the engine is an electric motor. The calculating means includes means for adding the output of the engine and the output of the electric motor to calculate the current system output. The conversion means includes means for converting the current system output into an equivalent rotational speed using the maximum system output of the hybrid vehicle defined by using the vehicle speed as a parameter.

  According to the second invention, the current system output is calculated by adding the output of the engine and the output of the electric motor. The ratio of the current system output to the maximum system output of the hybrid vehicle (which may be the maximum torque in this case) determined by the vehicle speed is calculated and converted to an equivalent rotational speed. If it does in this way, it can convert into the equivalent number of rotations which shows the same behavior as the number of rotations in vehicles carrying only an engine.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, the control block diagram of the whole hybrid vehicle including the display apparatus which concerns on embodiment of this invention is demonstrated. The present invention is not limited to the hybrid vehicle shown in FIG. In the present invention, an internal combustion engine such as a gasoline engine (hereinafter referred to as an engine) as a power source may be a drive source for driving a vehicle and a generator drive source. Furthermore, the drive source is an engine and a motor generator, and any vehicle that can travel with the power of the motor generator (whether the engine is stopped or not stopped) may be used. (It is not limited to so-called series type or parallel type hybrid vehicles). This battery is a nickel metal hydride battery or a lithium ion battery, and the type thereof is not particularly limited. A capacitor may be used instead of the battery.

  The hybrid vehicle includes an engine 120 and a motor generator (MG) 140. In the following, for convenience of explanation, the motor generator 140 is expressed as a motor generator 140A (or MG (2) 140A) and a motor generator 140B (or MG (1) 140B). Accordingly, motor generator 140A functions as a generator, or motor generator 140B functions as a motor. Regenerative braking is performed when this motor generator functions as a generator. When the motor generator functions as a generator, the kinetic energy of the vehicle is converted into electric energy, and the vehicle is decelerated.

  In addition to this, the hybrid vehicle transmits a power generated by the engine 120 and the motor generator 140 to the drive wheels 160, and transmits a drive of the drive wheels 160 to the engine 120 and the motor generator 140, and an engine. Power split mechanism (for example, a planetary gear mechanism described later) 200 that distributes the power generated by 120 to two paths of drive wheel 160 and motor generator 140B (MG (1) 140B), and motor generator 140 for driving Traveling battery 220 for charging electric power, and inverter that performs current control while converting the direct current of traveling battery 220 and the alternating current of motor generator 140A (MG (2) 140A) and motor generator 140B (MG (1) 140B) 240 and charging / discharging of traveling battery 220 A battery control unit (hereinafter referred to as a battery ECU (Electronic Control Unit)) 260 that manages and controls a state (for example, SOC (State Of Charge)), an engine ECU 280 that controls the operating state of the engine 120, and a hybrid vehicle state. Accordingly, MG_ECU 300 for controlling motor generator 140, battery ECU 260, inverter 240, etc., and battery ECU 260, engine ECU 280, MG_ECU 300, etc. are mutually managed and controlled so that the hybrid vehicle can operate most efficiently. HV_ECU 320 and the like are included.

  Further, HV_ECU 320 outputs a command signal for displaying engine equivalent rotational speed NE (EQ) on display unit 1100 to meter ECU 1000. The display device according to the present embodiment displays engine equivalent rotational speed NE (EQ) calculated by HV_ECU 320. This engine equivalent rotational speed NE (EQ) is calculated by a program executed by HV_ECU 320. Note that the engine equivalent rotational speed NE (EQ) is not calculated by the HV_ECU 320 in this way, but may be calculated by the meter ECU 1000 and displayed on the display unit 1100. That is, it is not limited which ECU calculates the engine equivalent rotational speed NE (EQ). In the following description, it is assumed that the engine equivalent rotational speed NE (EQ) calculated by the HV_ECU 320 is displayed on the display unit 1100 via the meter ECU 1000.

  In the present embodiment, boost converter 242 is provided between battery for traveling 220 and inverter 240. This is because the rated voltage of battery for traveling 220 is lower than the rated voltage of motor 140A (MG (2) 140A) or motor generator 140B (MG (1) 140B), so that motor generator 140A (MG (2) When power is supplied to 140A) or motor generator 140B (MG (1) 140B), the boost converter 242 boosts the power.

  In FIG. 1, each ECU is configured separately, but may be configured as an ECU in which two or more ECUs are integrated (for example, MG_ECU 300 and HV_ECU 320 are integrated as shown by a dotted line in FIG. 1). An example of this is the ECU.

  In power split mechanism 200, a planetary gear mechanism (planetary gear) is used to distribute the power of engine 120 to both drive wheel 160 and motor generator 140B (MG (1) 140B). By controlling the rotation speed of motor generator 140B (MG (1) 140B), power split device 200 also functions as a continuously variable transmission. The rotational force of the engine 120 is input to the carrier (C), which is output to the motor generator 140B (MG (1) 140B) by the sun gear (S), and the motor generator 140A (MG (2) 140A) and output by the ring gear (R). It is transmitted to the shaft (drive wheel 160 side). When the rotating engine 120 is stopped, since the engine 120 is rotating, the kinetic energy of this rotation is converted into electric energy by the motor generator 140B (MG (1) 140B), and the rotational speed of the engine 120 is reduced. Let

  In a hybrid vehicle equipped with a hybrid system as shown in FIG. 1, if a predetermined condition is satisfied for the state of the vehicle, HV_ECU 320 uses only motor generator 140A (MG (2) 140A) of motor generator 140 to hybrid vehicle. The engine 120 is controlled via motor generator 140A (MG (2) 140A) and engine ECU 280 so as to perform the following traveling. For example, the predetermined condition is a condition that the SOC of traveling battery 220 is equal to or greater than a predetermined value. In this way, the hybrid vehicle can be driven only by the motor generator 140A (MG (2) 140A) when the engine 120 is inefficient at the time of starting or running at a low speed. As a result, the SOC of the traveling battery 220 can be reduced (the traveling battery 220 can be charged when the vehicle is subsequently stopped).

  Further, during normal travel, for example, the power split mechanism 200 divides the power of the engine 120 into two paths, and on the other hand, the drive wheels 160 are directly driven, and on the other hand, the motor generator 140B (MG (1) 140B) is driven to generate power. To do. At this time, motor generator 140A (MG (2) 140A) is driven by the generated electric power to assist driving of driving wheels 160. Further, at the time of high speed traveling, the electric power from the traveling battery 220 is further supplied to the motor generator 140A (MG (2) 140A) to increase the output of the motor generator 140A (MG (2) 140A) to the driving wheel 160. To add driving force. On the other hand, at the time of deceleration, motor generator 140 </ b> A (MG (2) 140 </ b> A) driven by drive wheel 160 functions as a generator to perform regenerative power generation, and the collected power is stored in traveling battery 220. When the amount of charge of traveling battery 220 is reduced and charging is particularly necessary, the output of engine 120 is increased to increase the amount of power generated by motor generator 140B (MG (1) 140B), and traveling battery 220 is increased. Increase the amount of charge for.

  In addition, the target SOC of traveling battery 220 is normally set to about 60% so that energy can be recovered no matter when regeneration is performed. Further, the upper limit value and the lower limit value of the SOC are set, for example, with the upper limit value set to 80% and the lower limit value set to 30% in order to suppress the deterioration of the battery of the traveling battery 220. The HV_ECU 320 is set via the MG_ECU 300. Thus, power generation and regeneration by the motor generator 140 and motor output are controlled so that the SOC does not exceed the upper limit value and the lower limit value. In addition, the value quoted here is an example and is not a particularly limited value.

  The power split mechanism 200 will be further described with reference to FIG. The power split mechanism 200 includes a sun gear (S) 202 (hereinafter simply referred to as the sun gear 202), a pinion gear 204, a carrier (C) 206 (hereinafter simply referred to as the carrier 206), and a ring gear (R) 208 ( Hereinafter, it is composed of a planetary gear including a ring gear 208).

  Pinion gear 204 is engaged with sun gear 202 and ring gear 208. The carrier 206 supports the pinion gear 204 so that it can rotate. Sun gear 202 is coupled to the rotation shaft of MG (1) 140B. Carrier 206 is connected to the crankshaft of engine 120. Ring gear 208 is connected to the rotation shaft of MG (2) 140A and reduction gear 180.

  Engine 120, MG (1) 140B and MG (2) 140A are connected via power split mechanism 200 formed of a planetary gear, so that the rotational speeds of engine 120, MG (1) 140B and MG (2) 140A For example, as shown in FIG. 3, the relationship is a straight line in the collinear diagram (FIG. 3 is an example during steady operation).

  More specifically, when the rotational speeds of two of the three rotational shafts in power split mechanism 200 are determined, the rotational speeds of the remaining rotational shafts are determined. The relationship between the rotational speeds of the respective rotary shafts is as shown in the following equation (1).

N (C) = N (S) × ρ / (1 + ρ) + N (R) × 1 / (1 + ρ) (1)
Here, N (C) is the rotational speed of the carrier 206, N (S) is the rotational speed of the sun gear 202, and N (R) is the rotational speed of the ring gear 208. Further, ρ is a gear ratio between the sun gear 202 and the ring gear 208 as represented by the following equation.

ρ = (number of teeth of sun gear 202) / (number of teeth of ring gear 208)
Further, the torques of the three rotating shafts have a certain relationship given by the following expressions (2) and (3) regardless of the number of rotations.

T (S) = T (C) × ρ / (1 + ρ) (2)
T (R) = T (C) × 1 / (1 + ρ) = T (S) / ρ (3)
Here, T (C) is the torque of the carrier 206, T (S) is the torque of the sun gear 202, and T (R) is the torque of the ring gear 208. In addition, the code | symbol is not attached | subjected here.

  The hybrid vehicle can travel in various states by such a function of the power split mechanism 200.

  FIG. 4 shows the maximum torque characteristics as a hybrid system in this hybrid vehicle. The maximum torque T (MAX) as a hybrid system is defined by a map using the vehicle speed VE as a parameter. Basically, the maximum torque T (MAX) decreases as the vehicle speed VE increases. However, the maximum torque T (MAX) is a constant value in a predetermined low speed region. Note that the present invention is not limited to the case defined by the map.

  A control structure of a program executed by HV_ECU 320 that controls the display device according to the present embodiment will be described with reference to FIG. The program (subroutine) shown in this flowchart is repeatedly executed with a predetermined cycle time (for example, 80 msec).

  In step (hereinafter, step is described as S) 100, HV_ECU 320 calculates torque T (S) generated by motor generator 140B (MG (1) 140B). At this time, HV_ECU 320, for example, motor generator 140B based on the output power value from the inverter that supplies power to motor generator 140B (MG (1) 140B), the efficiency of motor generator 140B (MG (1) 140B), and the like. A generated torque T (S) of (MG (1) 140B) is calculated.

  In S200, HV_ECU 320 calculates generated torque T (C) of engine 120 using equation (2) described above. Here, a sign is added to Expression (2), and the generated torque T (C) of the engine 120 is calculated by − ((1 + ρ) / ρ) × T (S).

  In S300, HV_ECU 320 detects engine speed NE. In S400, HV_ECU 320 calculates actual generated power P (E) of engine 120. Here, the actual generated power P (E) of the engine 120 is calculated by T (C) × NE × k (k: coefficient).

  In S500, HV_ECU 320 detects the voltage (battery voltage V) and current (battery current I) of battery for traveling 220.

  In S600, HV_ECU 320 calculates motor power P (M) by motor generator 140A (MG (2) 140A). Here, the motor power P (M) is calculated by battery voltage V × battery current I.

  In S700, HV_ECU 320 calculates currently generated power P (TOTAL) generated as the current hybrid system. Here, the currently generated power P (TOTAL) is calculated by adding the actual generated power P (E) of the engine 120 and the motor power P (M).

  In S800, HV_ECU 320 detects current vehicle speed VE. In S900, HV_ECU 320 calculates maximum torque T (MAX) as a hybrid system at the current vehicle speed VE based on the map shown in FIG.

  In S1000, HV_ECU 320 calculates rotation speed η by dividing currently generated power P (TOTAL) by maximum torque T (MAX) as a hybrid system at current vehicle speed VE.

  In S1100, HV_ECU 320 converts engine speed η to engine equivalent engine speed NE (EQ). Here, the engine equivalent rotational speed NE (EQ) is calculated by multiplying the rotational speed η by a coefficient.

  In S1200, HV_ECU 320 outputs a command signal for displaying engine equivalent rotational speed NE (EQ) on display unit 1100 to meter ECU 1000.

  An operation of HV_ECU 320 that controls the display device according to the present embodiment based on the above-described structure and flowchart will be described.

  When the hybrid vehicle is running with engine 120 and motor generator 140, generated torque T (S) of motor generator 140B (MG (1) 140B) is calculated (S100), and the alignment chart shown in FIG. And the generated torque T (C) of the engine 120 is calculated by an equation obtained by converting the equation (2) (S200).

  The rotational speed NE of the engine 120 is detected (S300), and the actual generated power P (E) of the engine 120 is added to the generated torque T (C) of the engine 120 calculated in S200. (S400). The voltage V and current I of the traveling battery are detected (S500) and multiplied to calculate motor power P (M) (S600). The power currently generated as a hybrid system is calculated as currently generated power P (TOTAL) (S700).

  The vehicle speed VE is detected (S800), and the maximum torque T (MAX) that can be generated as a hybrid system at the vehicle speed VE is calculated from the map shown in FIG. 4 (S900). The rotational speed η is calculated by the current generated power P (TOTAL) / maximum torque T (MAX) (S1000), and converted to the engine equivalent rotational speed NE (EQ) (S1100). A command signal is output to meter ECU 1100 so that engine equivalent rotation speed NE (EQ) is displayed on rotation speed meter 1104 of display unit 1100 shown in FIG. 6 (S1200). The display unit 1100 is provided with a speedometer 1102, a fuel gauge 1106, and a water temperature gauge 1108 in addition to the rotational speed meter 1104.

  In this way, like a conventional vehicle using only the engine as a power source, a numerical value obtained by converting the power currently generated as a hybrid system into the engine speed is displayed on the tachometer that displays the engine speed. be able to. For this reason, even if a driver who is accustomed to driving a vehicle equipped only with an engine and knows the vehicle's running state based on the number of engine revolutions drives an unfamiliar hybrid vehicle, the engine equivalent rotation is performed in the same sense. Since the traveling state of the vehicle can be grasped by several NE (EQ), the state of the vehicle can be intuitively grasped.

<Modification>
In addition, you may make it display whether it is a driving | running | working state of EV driving | running | working, HV driving | running | working, and engine driving | running | working on an instrument panel. By providing such a display of the running state, whether the revolution meter 1104 is a converted value of the motor output (EV running), a converted value of the motor and engine output (HV running), or the actual It is possible to notify the driver of whether the engine speed is displayed (engine running). For this reason, the driving state of the vehicle can be notified to the driver in more detail.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a control block diagram of the whole hybrid vehicle including the display apparatus which concerns on this Embodiment. It is a figure which shows a power split mechanism. It is an alignment chart which shows the relationship between the rotation speed of an engine, MG (1), and MG (2). It is a figure which shows the maximum torque characteristic as a hybrid system. It is a flowchart which shows the control structure of the program performed by HV_ECU which controls the display apparatus which concerns on this Embodiment. It is a figure which shows the display part provided in an instrument panel.

Explanation of symbols

  120 engine, 140 motor generator, 160 driving wheel, 180 reduction gear, 200 power split mechanism, 220 battery for traveling, 240 inverter, 242 boost converter, 260 battery ECU, 280 engine ECU, 300 MG_ECU, 320 HV_ECU.

Claims (2)

A display device for a hybrid vehicle having an engine and a power source other than the engine as a travel source of the vehicle,
Calculating means for calculating the output of the travel source by adding the output of the engine and the output of a power source other than the engine ;
Conversion means for converting the calculated output into an equivalent rotational speed corresponding to the rotational speed of the engine;
A display device for a hybrid vehicle, comprising: display means for displaying the equivalent rotational speed on a rotational speed meter displaying the same unit as an engine rotational speed meter provided in a vehicle having only the engine as a travel source. The power source other than the engine is an electric motor,
The calculating means includes means for calculating a current system output by adding the output of the engine and the output of the electric motor,
2. The hybrid vehicle according to claim 1, wherein the conversion means includes means for converting the current system output into the equivalent rotational speed using a maximum system output of the hybrid vehicle defined by using a vehicle speed as a parameter. Display device.

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