JP6227465B2 - Engine control device and hybrid vehicle - Google Patents

Description

  The present invention relates to an engine control device, and more particularly to engine speed control in a hybrid vehicle.

  Conventionally, various engine control methods for hybrid vehicles have been proposed.

  For example, a technique is proposed in which the engine output is determined so that the required output determined by the accelerator opening, vehicle speed, battery charging request, etc. is output by the engine itself, and the target value of the engine speed is determined and controlled based on this engine output Has been.

  In addition, when traveling using a plurality of virtual target shift stages, so-called sequential shifts, in which the ratio of the engine speed change amount to the vehicle speed change amount is fixed, the torque based on the accelerator opening is set to an upper limit value and a lower limit value based on the shift position. The required torque is set by limiting by the value, and the engine target torque is set by limiting the torque that outputs the required power with the upper limit value and the lower limit value based on the target engine speed based on the vehicle speed and shift position and the battery charge / discharge required power. A technique has also been proposed in which the two motors are controlled such that the engine is operated at the target rotational speed and target torque and the required torque is output while the engine is running.

JP 2006-321458 A

  In a two-motor type hybrid vehicle, a difference between a change in vehicle speed during acceleration and a change in engine speed occurs, so that the acceleration feeling (acceleration feeling) felt by the driver can be impaired. That is, when the engine output is determined so that the requested output determined by the accelerator opening, vehicle speed, battery charging request, etc. is output by the engine itself, immediately after the start of acceleration, the engine speed rapidly increases to increase the engine output, and then the engine A profile is obtained in which the rotational speed is substantially constant, and such a change in the engine rotational speed is not linked to the vehicle speed, which may cause a feeling of strangeness in the acceleration feeling.

  In addition, when setting the target engine speed based on the vehicle speed and the shift position, the relationship between the vehicle speed and the engine speed can be changed only by a preset inclination and intercept, and the relationship is not affected by the driving state. Depending on the state, there may be a case where acceleration characteristics corresponding to the accelerator opening cannot be obtained due to limitations of engine torque and motor torque. Further, since the shift position is determined by the driver's shift operation, the relationship between the vehicle speed and the engine speed is fixed unless the driver performs the shift operation, and the fuel efficiency may deteriorate.

  An object of the present invention is to improve the acceleration feeling (acceleration feeling) during acceleration by appropriately controlling the engine speed in a hybrid vehicle.

The present invention relates to an engine control apparatus for a hybrid vehicle that includes an engine, a battery, and a motor, and that travels by driving the motor using electric power generated by the engine, the target rotation of the engine during acceleration A calculation means for setting a number, and when the engine speed reaches a threshold speed, the target speed of the engine is set in proportion to the vehicle speed, and the proportionality coefficient is set to the accelerator opening, the vehicle speed, and the engine speed. And calculating means for setting based on the charging rate of the battery, the calculating means at the time of starting acceleration, when reaching a predetermined engine speed, or when reaching a predetermined accelerator opening The proportional coefficient is set based on an accelerator opening, a vehicle speed, an engine speed, and a charging rate of the battery .

  In the present invention, when the engine speed reaches the threshold speed, the engine output is not determined so that the required output determined from the accelerator opening is output mainly by the engine as in the prior art, but proportional to the vehicle speed. Set the target engine speed so that As a result, a sudden increase in the engine speed immediately after acceleration is suppressed, and an increase in engine speed commensurate with an increase in vehicle speed is realized to improve acceleration feeling. Also, when setting the target engine speed to be proportional to the vehicle speed, the proportional coefficient is set based on the accelerator opening, the vehicle speed, the engine speed, and the battery charge rate. The proportional relationship is realized.

  In the present invention, the proportionality coefficient is set based on the accelerator opening, the vehicle speed, the engine speed, and the battery charging rate, but the case where the proportionality coefficient is set by further using other physical quantities or parameters is excluded. It is not a thing.

When the proportional coefficient is set based on the accelerator opening, the vehicle speed, the engine speed, and the battery charging rate, the proportional coefficient is aaa, the accelerator opening is Acc, the vehicle speed is V, the engine speed is Ne, and the battery Assuming that the charging rate is SOC,
aaa = f (V, Acc, Ne, SOC)
Can be described. Here, f is a specific function.

  In one embodiment of the present invention, the calculation means sets a target rotational speed corresponding to a required driving force set from the accelerator opening until the engine rotational speed reaches the threshold rotational speed, When the number reaches the threshold speed, the target engine speed is set in proportion to the vehicle speed, and the target speed set in proportion to the vehicle speed depends on the required driving force set from the accelerator opening. When the target rotational speed is reached, the target rotational speed corresponding to the required driving force set from the accelerator opening is set again.

In another embodiment of the present invention, the calculating means may prevent the engine speed from becoming discontinuous when the threshold speed is Nep, the proportionality factor is aaa, and the vehicle speed is V.
bbb = Nep-aaa * V
Then, the intercept bbb is set, and the target rotational speed is set in proportion to the vehicle speed in a proportional relationship determined by the proportional coefficient aaa and the intercept bbb.

In addition, the present invention is a hybrid vehicle that includes an engine, a battery, and a motor, and that travels by driving the motor using electric power generated by the engine, the means for detecting an accelerator opening, vehicle speed Detecting means, means for detecting the engine speed, means for detecting the charging rate of the battery, and arithmetic means for setting the target engine speed during acceleration, the engine speed being reduced. When the threshold speed is reached, the target engine speed is set in proportion to the vehicle speed, and the proportionality coefficient is set based on the accelerator opening, the vehicle speed, the engine speed, and the battery charge rate. comprising means, the computing means during acceleration starts, the time of reaching the predetermined engine speed, the accelerator at any time of reaching a predetermined accelerator opening Time, vehicle speed, engine speed, and characterized by setting the proportional coefficient based on the charging rate of the battery.

  The engine control device and hybrid vehicle of the present invention will be more clearly understood with reference to the following embodiments. However, the following embodiment is an exemplification, and the present invention is not limited to the following embodiment.

  According to the present invention, acceleration feeling can be improved by appropriately controlling the engine speed during acceleration. In particular, according to the present invention, it is possible to suppress a sudden increase in the engine speed during acceleration, a discontinuous decrease in the engine speed, etc., to obtain an engine speed proportional to an increase in vehicle speed, and to obtain a proportional coefficient in the proportional relationship. A good acceleration feeling can be obtained because the coefficient is suitable for the running state of the vehicle.

It is a lineblock diagram of a hybrid car of an embodiment. It is a processing flowchart of an embodiment. It is explanatory drawing which shows an example of an engine operating point setting map. It is time change explanatory drawing of the acceleration of embodiment, an engine speed, and an engine driving force. It is time change explanatory drawing of the acceleration and engine speed of other embodiment. It is a block diagram of the hybrid vehicle of other embodiment.

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

  FIG. 1 shows a configuration of a two-motor type hybrid vehicle. The hybrid vehicle includes an engine 100, a generator MG1, a motor MG2, and a battery (battery) 500. Engine 100, generator MG <b> 1, motor MG <b> 2 and tire (drive wheel) 400 are connected via power distribution mechanism 700.

  The power distribution mechanism 700 is configured by a known planetary gear mechanism. A generator MG1 is connected to the sun gear, a motor MG2 is connected to the ring gear, and the engine 100 is connected to a carrier that holds the pinion gear engaged with the sun gear and the ring gear so as to rotate and revolve. Further, a differential is connected to the ring gear via an output shaft, and power is transmitted from the differential to the left and right tires 400.

  The generator MG1 and the motor MG2 are each connected to an inverter, and the inverter is electrically connected to the battery 500 for power transmission and reception. A converter may be provided between the battery 500 and the inverter. The generator MG1 generates power using the power of the engine 100 and supplies the generated power to the battery 500 via the motor MG2 and the inverter. Motor MG2 generates driving force for driving using electric power from battery 500 and electric power from generator MG1 to drive tire 400. The generator MG1 can also function as a motor for motoring (cranking) of the engine 100. Further, when the hybrid vehicle is coasting or decelerating, the motor MG2 stops the fuel supply and ignition to the engine 100 and drives the motor MG2 with the torque transmitted from the output shaft to function as a generator. You can also. Since engine 100 and generator MG1 are connected via power distribution mechanism 700, when functioning generator MG1 as a generator, the rotation speed of engine 100 can be changed according to the rotation speed of generator MG1. it can. When engine 100 is running with power output, negative torque such as running resistance acts on the ring gear, and positive torque outputted by engine 100 acts on the carrier. At this time, if a negative torque is applied to the sun gear, a positive torque obtained by amplifying the engine torque is applied to the ring gear. The negative torque that acts on the sun gear is generated by causing the generator MG1 connected to the sun gear to function as a generator. Decreasing the rotational speed of the generator MG1 decreases the rotational speed of the engine 100, and increasing the rotational speed of the generator MG1 increases the rotational speed of the engine 100. The generator MG1 and the motor MG2 are driven and controlled by an ECU, particularly a vehicle control ECU 600, via an inverter. In addition to the vehicle control ECU 600, the ECU includes an MG control ECU 602, an engine ECU 604, and a battery monitoring ECU 606. Of course, these ECUs do not necessarily have to be separate, and at least any one or more or all of them may be constituted by a single ECU.

The vehicle control ECU 600 as a calculation means is constituted by a microcomputer having a CPU and a memory, and controls various generators MG1 and motor MG2 by inputting various detection signals.
That is, the vehicle control ECU 600 determines the accelerator signal (accelerator opening) from the accelerator opening sensor, the engine speed from the engine speed sensor, the motor speed from the motor MG2, and the charging rate SOC of the battery 500 from the battery monitoring ECU 606. , The generator / motor command torque is calculated and output to the MG control ECU 602. The MG control ECU 602 outputs drive signals (switching signals) to the respective inverters to drive the generator MG1 and the motor MG2 with the supplied command torque. The state of the inverter and the states of the generator MG1 and the motor MG2 are monitored by the MG control ECU 602. Further, vehicle control ECU 600 calculates a target rotational speed of engine 100 based on the accelerator signal, the motor rotational speed, the SOC, and the engine rotational speed, and outputs it to engine ECU 604. The engine ECU 604 controls to drive the engine 100 at the supplied target rotational speed. Here, the vehicle control ECU 600 calculates the vehicle speed from the motor rotation speed proportional to the vehicle speed, and calculates the target rotation speed of the engine 100. Further, the charging rate (SOC) of the battery 500 is calculated by the battery monitoring ECU 606 based on the integrated value of the charging / discharging current of the battery 500 detected by a current sensor or the like.

  When the output of the engine 100 is determined so that the required output determined from the accelerator opening is output mainly by the engine 100 at the time of acceleration, immediately after the acceleration starts, the engine speed rapidly increases to increase the output of the engine 100, and the acceleration Feeling is impaired. Therefore, as a basic principle, the vehicle control ECU 600 according to the present embodiment controls the engine speed to be proportional to the vehicle speed at the time of acceleration, and sets the proportional coefficient at this time to a proportional coefficient according to the traveling state of the hybrid vehicle.

  FIG. 2 shows a calculation process flowchart of the target rotational speed of engine 100 in vehicle control ECU 600. This processing flowchart is repeatedly executed at a predetermined control cycle (for example, every several msec).

First, various notations in the figure will be described.
Acc: accelerator opening degree V: vehicle speed τdrv: vehicle driving force required by the driver (required driving torque)
Netag_bs: target engine speed (reference target engine speed)
Peg_bs: Target engine output (reference target engine output)
Ne: Current engine speed flag_a: Engine speed control flag Nep: Threshold speed for changing engine speed control Netag: Final target engine speed Peg: Final target engine output

  In FIG. 2, the vehicle control ECU 600 acquires the accelerator opening Acc and the vehicle speed V detected by the accelerator opening detection sensor (S101). The vehicle speed V is calculated from the motor speed as described above. Then, based on the accelerator opening Acc and the vehicle speed V, the driving force of the vehicle requested by the driver is calculated (S102). The vehicle control ECU 600 refers to a map that prestores the accelerator opening degree Acc, the vehicle speed V, and the required drive torque τdrv, and stores the required drive corresponding to the acquired accelerator opening degree Acc and the vehicle speed V. Torque τdrv is acquired.

  Next, the vehicle control ECU 600 calculates a reference target engine speed Netag_bs and a target engine output Peg_bs based on the required drive torque τdrv (S103). That is, an output requested by the driver is calculated based on the required driving torque τdrv and the vehicle speed V at that time, and an engine operating point setting map stored in advance in the memory is referred to. The engine speed that satisfies the required output and operates on the operation line such as the optimum fuel consumption line Cf is calculated. The engine operating point setting map is well known, and as shown in FIG. 3, the relationship between the engine speed Ne, the engine torque Te, the equal output line Pe, and the operation line indicated by the optimum fuel consumption line Cf is determined in advance. is there. In FIG. 3, the engine speed is set as the intersection of the output line Pe = constant curve corresponding to the driver request output and the optimum fuel consumption line Cf. After calculating the engine speed Netag_bs, the vehicle control ECU 600 determines whether or not the hybrid vehicle is accelerating (S104).

  When the hybrid vehicle is not accelerating (NO in S104), the engine speed Nettag_bs calculated in S103 is determined as the final target engine speed Netag (S114), and the engine speed control flag flag_a is reset to 0. (S115). The engine 100 is controlled to be the target engine speed Nettag.

  When the hybrid vehicle is accelerating (YES in S104), the vehicle control ECU 600 acquires the current engine speed Ne and the charging rate (SOC) of the battery 500 (S105). The charging rate (SOC) of the battery 500 is detected by the battery monitoring ECU 606, but may be detected by the vehicle control ECU 600.

Next, the value of the engine speed control flag flag_a is checked (S106). The initial value of the flag flag_a is set to 0. As a result of the check, if flag_a = 0, the threshold rotational speed Nep and the function parameter are calculated (S112). Specifically, the threshold rotational speed Nep, the proportionality coefficient aaa and the intercept bbb as function parameters are set as follows.
Nep = func1 (V, Acc, Ne, SOC)
aaa = func2 (V, Acc, Ne, SOC)
bbb = Nep-aaa * V

  Here, func1 (V, Acc, Ne, SOC) indicates, for example, a function of the vehicle speed V at the start of acceleration, the accelerator opening degree Acc, the engine speed Ne, and the charging rate SOC. The same applies to func2 (V, Acc, Ne, SOC). It should be noted that the proportionality factor aaa is set based on the vehicle speed V at the start of acceleration, the accelerator opening degree Acc, the engine speed Ne, and the charging rate (SOC) of the battery 500. This is because, for example, a proportional coefficient that matches the acceleration feeling felt by the driver is calculated based on the accelerator opening at the start of acceleration, the vehicle speed V, the engine speed Ne, and the like. The threshold rotational speed Nep may be a predetermined value instead of being adaptively set as a function of the vehicle speed V or the like. Further, the vehicle control ECU 600 uses the function func2 stored in the memory to calculate the proportional coefficient aaa, and the correspondence relationship of the proportional coefficient aaa, the accelerator opening degree Acc, the vehicle speed V, the engine speed Ne, and the charging rate SOC. The proportionality coefficient aaa may be calculated with reference to a predetermined map.

  After setting the threshold rotational speed Nep, the proportionality factor aaa and the intercept bbb based on the vehicle speed V, the accelerator opening degree Acc, the engine rotational speed Ne, and the charge rate SOC, the target engine rotational speed and the threshold rotational speed Nep are compared in magnitude. (S113). Since the engine speed is controlled to become the target engine speed, this determination process is equivalent to comparing the current engine speed with the threshold speed Nep.

  If Netag <Nep (YES in S113), this means that the threshold rotational speed Nep has not yet been reached even during acceleration. Therefore, the engine rotational speed Netag_bs calculated in S103 is used as the final target engine rotational speed. It continues to be determined as Netag (S114), and the engine speed control flag flag_a is reset to 0 (S115). Accordingly, in this case as well, the engine speed is controlled to become the target engine speed Netag, that is, the target engine speed set based on the driver's required driving force, and the engine speed increases.

  On the other hand, if Netag <Nep is not satisfied (NO in S113), that is, if the target engine speed (= current engine speed) is equal to or higher than the threshold speed Nep, then the calculation is performed in Netag and S103. The current Netag_bs is compared in size (S107).

If Netag <Netag_bs (YES in S107), that is, if Nep ≦ Netag <Netag_bs, the target engine speed Netag is calculated (S108). Specifically, using the proportionality coefficient aaa and intercept bbb calculated in S112,
Netag = aaa * V + bbb
To calculate the target engine speed Nettag. As can be seen from the above equation, when the threshold rotational speed Nep is exceeded, the target engine rotational speed Netag is set according to the vehicle speed V in a proportional relationship determined by the proportional coefficient aaa. Here, since the intercept bbb of the proportional relationship is calculated as bbb = Nep−aaa * V in S112, the target engine speed Nep is continuous before and after the threshold speed Nep. While maintaining the state as it is, it is possible to shift from the conventional target engine speed to the target engine speed calculated by Netag = aaa * V + bbb. Since the target engine speed Netag is set in proportion to the vehicle speed V, an engine speed that matches the acceleration feeling can be obtained. After calculating the target engine speed Netag, the final target engine output Peg is calculated by Peg = Netag * engine torque based on the target engine speed Netag and the corresponding engine torque (S109). The engine torque corresponding to the engine speed Netag can be set using the engine operating point setting map of FIG. If there is a divergence between the final target engine output Peg and the reference target engine output Peg_bs calculated in S103 (normally, Peg <Peg_bs and the output is insufficient), the difference (insufficient) is calculated. In order to compensate for the power from the battery 500, the output increment of the battery 500 is calculated by Peg_bs-Peg (S110). After calculating the final target engine speed Netag, the engine speed control flag flag_a is set to 1 (S111). The engine speed is controlled to be the target engine speed Netag, that is, the engine speed proportional to the vehicle speed V.

  Further, if Netag <Netag_bs in S107 (NO in S107), that is, if Netag_bs ≦ Netag, the final target engine speed is set as Netag = Netag_bs (S116) so that the same control as in the conventional case is performed again (S116). The rotation speed control flag flag_a is set to 2 (S117). Thereafter, when the value of flag_a is checked in S106, the value of flag_a is other than 0 or 1 when flag_a = 2, and therefore the target engine speed Netag_bs calculated in S103 according to S116 is the final value as it is. The target engine speed Nettag is obtained.

  In summary, in this embodiment, the target engine speed is adaptively calculated as follows according to the magnitude relationship between the target engine speed Netag (or the current engine speed Ne) and the threshold speed Nep.

(1) When Netag <Nep The engine speed is controlled by calculating the target engine speed based on the driver's required driving force τdrv and the vehicle speed V, as in the conventional case.
flag_a = 0

(2) Case of Nep ≦ Netag <Netag_bs This is a target engine speed specific to the present embodiment, and the target engine speed is calculated by Netag = aaa * V + bbb to control the engine speed.
flag_a = 1

(3) Case of Netag_bs <Netag The target engine speed based on the driver's required driving force τdrv and the vehicle speed V is calculated and the engine speed is controlled as in the conventional case.
flag_a = 2

  As in the case of calculating the target engine speed from the vehicle speed V and the shift position, it is not set uniquely from the relationship between the vehicle speed V and the engine speed set in advance, but adaptively according to the driving state. Therefore, the acceleration characteristic corresponding to the accelerator opening degree Acc is obtained, and the acceleration feeling can be improved. In addition, when calculating the target engine speed from the shift position, the target engine speed changes discontinuously at the time of shifting, and so-called driving force loss may occur. In this embodiment, the target engine speed calculation logic is changed. Even when (specifically, when the calculation logic is changed from (1) to (2) above), since the proportionality intercept bbb is calculated as indicated by S112, the target engine before and after the change is calculated. The rotational speed does not change discontinuously and there is no driving force loss.

  Next, the engine speed control in the present embodiment will be described more specifically.

  FIG. 4 shows temporal changes in acceleration, engine speed, and engine driving force in the present embodiment. FIG. 4A shows the time change of acceleration. The acceleration is zero until a certain timing, and the acceleration is gradually increased when the driver depresses the accelerator pedal from a certain timing (“acceleration start” in the figure), and then the acceleration gradually decreases.

  FIG. 4B shows the change over time of the engine speed. FIG. 4B shows the engine speed in this embodiment, that is, the engine speed calculated by Netag = aaa * V + bbb, the reference engine speed Netag_bs, and the conventional engine speed described in Japanese Patent Laid-Open No. 2006-321458. The engine speed by the calculation method is also shown for comparison. When not accelerating, the target engine speed is also Netag_bs in this embodiment (see S114), and the engine speed is also controlled to match this. Even after acceleration, the target engine speed remains Netag_bs until the engine speed reaches the threshold speed Nep (corresponding to the determination of YES in S113). Therefore, the engine speed increases relatively steeply according to the driver's required driving force. However, when the engine speed reaches the threshold speed Nep, the engine speed is controlled to be the target engine speed calculated by Netag = aaa * V + bbb instead of Netag_bs (see S108 to S111). . Since the proportional coefficient aaa is proportional to the vehicle speed V and is set according to the vehicle speed V, the accelerator opening degree Acc, and the charging rate SOC of the battery 500, the engine speed corresponding to the traveling state and the vehicle speed V Therefore, a good acceleration feeling can be obtained. In the engine speed control based on Netag_bs, the engine speed increases excessively as compared with the vehicle speed V, so-called engine speed can be blown up. In this embodiment, such blow-up is effectively suppressed. Is done. Further, in the prior art disclosed in Japanese Patent Laid-Open No. 2006-321458 that controls the engine speed according to the shift position, the engine speed decreases discontinuously at the time of a shift even though the vehicle speed V does not change. However, in this embodiment, such reduction or stagnation of the engine speed is effectively suppressed.

  When the engine speed calculated by Netag = aaa * V + bbb reaches Netag_bs, the engine speed is controlled again based on Netag_bs (see S116). When the engine speed reaches Nep and the engine speed control logic switches from control based on Netag_bs to control based on Netag = aaa * V + bbb (point indicated by A in the figure), the engine speed changes discontinuously. It changes smoothly without.

  FIG.4 (c) shows the time change of an engine driving force. Similar to FIG. 4B, no driving force loss occurs at the point A at which the control logic switches, and no driving force loss during shifting (point indicated by B in the drawing) does not occur as in the prior art. In this embodiment, the advantage of calculating the target engine speed by Netag = aaa * V + bbb and controlling the engine speed based on this is obvious.

  In this embodiment, as shown in FIG. 4 (c), the engine speed is increased in proportion to the vehicle speed V to improve the acceleration feeling. As a result, the engine driving force becomes smaller than the required driving force. However, since the shortage is compensated by the power from the battery 500 as shown in S110, the required driving force can be maintained. That is, the motor torque in the hybrid vehicle shown in FIG. 1 is the sum of the motor torque corresponding to the engine power generation and the motor torque corresponding to the output of the battery 500. As a result of controlling the engine speed lower, the motor torque corresponding to the engine power generation is In the case of shortage, it can be said that the motor torque for the output of the battery 500 is compensated. When the charging rate SOC of the battery 500 is relatively low, it is difficult to compensate for the output of the battery 500, so the proportionality coefficient aaa is set based on the charging rate SOC. When the charging rate SOC is relatively low, the engine output can be increased rapidly by setting the proportionality factor aaa relatively large. The charge rate SOC may be compared with a threshold value, and the control in the present embodiment may be stopped when the charge rate SOC is not more than the threshold value and is extremely low. Usually, in order to prevent the battery 500 from being deteriorated due to overcharge or overdischarge, charge / discharge control is performed in an intermediate region between the upper limit value and the lower limit value according to the use state, temperature, and the like. Therefore, the threshold value is set to any value between the upper limit value and the lower limit value, but the upper limit value and the lower limit value can be changed according to the temperature condition and the degree of deterioration. Instead, it may vary depending on temperature conditions and the degree of deterioration. The same applies to the threshold rotation speed Nep.

In the present embodiment, the proportional coefficient aaa is aaa = func2 (V, Acc, Ne, SOC)
However, it is not always necessary to calculate the proportionality coefficient with one function, and it may be calculated with a plurality of functions. For example,
aaa1 = func21 (V, Acc, Ne, SOC)
aaa2 = func22 (V, Acc, Ne, SOC)
Thus, two different proportional coefficients aaa1 and aaa2 are calculated by different functions func21 and func22, and Netag = aaa1 * V + bbb1 using these proportional coefficients
Netag = aaa2 * V + bbb2
The target engine speed may be calculated by Here, bbb1 and bbb2 are different sections, and are set so as to change smoothly before and after the change. Nep1 and Nep2 (where Nep1 <Nep2) are set as threshold speeds, and when Nep1 is reached, the target engine speed is calculated using the proportionality coefficient aaa1 and the intercept bbb1, and when Nep2 is reached, the proportionality coefficient The target engine speed may be calculated using aaa2 and intercept bbb2.

FIG. 5 shows temporal changes in acceleration and engine speed when the proportionality coefficient aaa1 and the intercept bbb1, and the proportionality coefficient aaa2 and the intercept bbb2 are used. Fig.5 (a) shows the time change of an acceleration and is the same profile as Fig.4 (a). FIG. 5B shows the change over time of the engine speed. Control is performed based on Netag_bs until the threshold rotational speed Nep1 is reached, and when the threshold rotational speed Nep1 is reached, Netag = aaa1 * V + bbb1
To control the engine speed. Furthermore, when the threshold rotation speed Nep2 is reached,
Netag = aaa2 * V + bbb2
To control the engine speed. here,
aaa1> aaa2
It is. When Netag reaches Netag_bs, control is performed again based on Netag_bs thereafter.

  Both aaa1 and aaa2 are calculated in consideration of the charging rate SOC. In this example, too, when the charging rate SOC is relatively low, in order to increase the output of the engine 100 quickly and charge the battery 500, the aaa1 or aaa2 It is also preferable to calculate so that aaa2 is relatively large.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various deformation | transformation is possible.

  For example, in the present embodiment, the proportional coefficient aaa is calculated based on the vehicle speed V at the start of acceleration, the accelerator opening Acc, and the charge rate SOC of the battery 500, but is not limited to at the start of acceleration, and a predetermined engine speed May be calculated based on the vehicle speed V, the accelerator opening degree Acc, and the charging rate (SOC) of the battery 500, or the vehicle speed V when the predetermined accelerator opening degree is reached, and the accelerator opening. It may be calculated based on the degree Acc and the charging rate (SOC) of the battery 500.

  In the present embodiment, the power is generated by the generator MG1 using the power of the engine 100, the generated power is supplied to the motor MG2 and the battery 500, and driving power is generated by the motor MG2 to drive the driving wheels. Although described, the present invention can also be applied to the case where the torque generated by the engine 100 is directly used as the driving force.

  Further, in the present embodiment, as shown in FIG. 1, the motor speed is supplied to the vehicle control ECU 600 and the vehicle speed is calculated from the motor speed, but the wheel speed is more directly replaced with the motor speed. May be detected and supplied to the vehicle control ECU 600.

  FIG. 6 shows a block diagram of the configuration in this case. The difference from FIG. 1 is that the wheel speed is detected by a wheel speed sensor instead of the motor rotation speed, and is supplied to the vehicle control ECU 600. The vehicle control ECU 600 calculates the target rotational speed of the engine 100 based on the accelerator opening, the wheel speed, and the like, and outputs it to the engine ECU 604.

100 Engine, 400 Tire, 500 Battery, 600 Vehicle control ECU, 602 MG control ECU, 604 Engine ECU, 606 Battery monitoring ECU, 700 Power distribution mechanism, MG1 generator, MG2 motor.

Claims (5)

An engine control device in a hybrid vehicle comprising an engine, a battery, and a motor, and driving by driving the motor using electric power generated by the engine,
A calculation means for setting a target engine speed of the engine at the time of acceleration. When the engine speed reaches a threshold engine speed, the target engine speed of the engine is set in proportion to the vehicle speed, and a proportional coefficient is set. A calculating means for setting based on an accelerator opening, a vehicle speed, an engine speed, and a charging rate of the battery, and the calculating means has a predetermined accelerator opening at a time when a predetermined engine speed is reached at the start of acceleration. An engine control device, wherein the proportionality coefficient is set based on an accelerator opening degree, a vehicle speed, an engine speed, and a charge rate of the battery at any of the points of time reached . The engine control apparatus according to claim 1, wherein
The calculation means sets a target rotational speed corresponding to the required driving force set from the accelerator opening until the engine rotational speed reaches the threshold rotational speed, and the engine rotational speed reaches the threshold rotational speed. If the target rotational speed of the engine is set in proportion to the vehicle speed and the target rotational speed set in proportion to the vehicle speed reaches the target rotational speed corresponding to the required driving force set from the accelerator opening. An engine control device characterized by setting a target rotational speed corresponding to a required driving force set again from an accelerator opening. The engine control apparatus according to claim 2, wherein
When the threshold rotation speed is Nep, the proportionality factor is aaa, and the vehicle speed is V,
bbb = Nep-aaa * V
An engine control device characterized in that an intercept bbb is set in accordance with, and the target rotational speed is set in proportion to the vehicle speed in a proportional relationship determined by the proportional coefficient aaa and the intercept bbb. In the engine control device according to any one of claims 1 to 3,
The calculation means sets a first proportional coefficient and a second proportional coefficient different from each other as the proportional coefficient, and is proportional to the vehicle speed by the first proportional coefficient when the engine speed reaches the first threshold speed. And setting the engine speed in proportion to the vehicle speed by the second proportional coefficient when the engine speed reaches a second threshold speed greater than the first threshold speed. apparatus. A hybrid vehicle comprising an engine, a battery, and a motor, and driving by driving the motor using electric power generated by the engine,
Means for detecting the accelerator opening;
Means for detecting the vehicle speed;
Means for detecting the rotational speed of the engine;
Means for detecting the charging rate of the battery;
A calculation means for setting a target engine speed of the engine at the time of acceleration. When the engine speed reaches a threshold engine speed, the target engine speed of the engine is set in proportion to the vehicle speed, and a proportional coefficient is set. Calculation means for setting based on accelerator opening, vehicle speed, engine speed, and charging rate of the battery;
The calculation means includes an accelerator opening, a vehicle speed, an engine speed, and a charge of the battery at the time of starting acceleration, when a predetermined engine speed is reached, or when a predetermined accelerator opening is reached. A hybrid vehicle characterized in that the proportionality coefficient is set based on a rate .

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