JP6281486B2 - Control device - Google Patents

Description

  The present invention relates to a vehicle control device, and more particularly, to a technical field of a control device that controls a generator that is rotationally driven by an engine.

  As a device of this type, for example, in a hybrid vehicle, after the accelerator depression is stopped, the regenerative mode is entered on condition that the charging rate of the battery is low, and the motor / generator is used as a generator utilizing the inertia energy of the vehicle. There has been proposed a device that functions, collects electric power of a battery, and stops driving a motor / generator when the battery is sufficiently charged (see Patent Document 1).

  Alternatively, it is a device that generates power by driving the alternator by transmitting the rotation of the engine of the vehicle, and the voltage or power that the alternator generates and outputs is output on condition that the speed of decrease in engine speed exceeds a threshold value. There has been proposed a device that lowers the upper limit of the fDUTY to be defined as compared with normal time and prevents a significant drop in engine speed caused by the alternator (see Patent Document 2).

JP 2004-007948 A JP 2013-110937 A

  In the technique described in Patent Document 1, since the power generation torque related to the motor / generator in the regeneration mode is constant, there is a possibility that, for example, the engine speed may drop sharply or engine stall may occur. There is a problem. In the technique described in Patent Document 2, even if the engine speed is sufficiently high, the output of the alternator is uniformly limited if the speed of decrease in the engine speed exceeds the threshold value. There is.

  The present invention has been made in view of the above problems, for example, and an object of the present invention is to provide a control device capable of performing appropriate regenerative control in accordance with the engine speed.

In order to solve the above-described problem, the control device of the present invention is a vehicle control device including an engine and power generation means that generates electric power using rotational energy of the engine, and detects the rotational speed of the engine. An accelerator-off state is detected by an engine speed detecting means, an accelerator operation detecting means for detecting an accelerator operation related to the vehicle, an engine speed detecting means for detecting an engine speed change amount, and the accelerator operation detecting means. Power generation control means for setting the power generation torque related to the power generation means to be larger as the detected rotational speed is higher, and the power generation control means is configured to detect when the accelerator-off is detected. The detected rotational speed when the accelerator-off is detected when the detected rotational speed is a single value and the detected rotational speed change amount is a positive value. Wherein a first value, and the in comparison to when the detected speed change amount is a negative value, the so power torque increases, and sets the power generation torque.

  According to the control device of the present invention, the control device is mounted on a vehicle including an engine and power generation means that generates electric power using rotational energy of the engine. The power generation means is not limited to a generator such as an alternator, and may be a generator realized in a motor generator (motor generator). That is, as long as it can function as a power generation means, it may mean, for example, a motor / generator used in a hybrid vehicle.

  The control device includes a rotation speed detection unit, an accelerator operation detection unit, and a power generation control unit.

  Since various known modes can be applied to the rotation speed detection means for detecting the rotation speed of the engine and the accelerator operation detection means for detecting the accelerator operation related to the vehicle, a detailed description thereof will be omitted.

  For example, the power generation control means including a memory, a processor, and the like increases the power generation torque related to the power generation means as the rotation speed detected by the rotation speed detection means increases when the accelerator operation detection means detects accelerator off. Set.

  Here, according to the inventor's research, the following matters have been found. That is, when regenerative power generation is performed, the power generation torque of the power generation means is often set larger than when the regenerative power generation is not performed, and the engine risk increases due to regenerative power generation. On the other hand, from the viewpoint of drivability, it may be preferable to reduce the engine speed early. Specifically, for example, after the driver has stepped on the accelerator too much, when the driver stops the depression of the accelerator by reducing the engine speed, it is desirable to suppress unnecessary blowing of the engine.

  Therefore, in the present invention, as described above, when the accelerator-off is detected by the power generation control means, the power generation torque related to the power generation means is set larger as the engine speed is higher.

  For this reason, when the engine speed is relatively low, the power generation torque is set to be relatively small, so that a significant drop in the engine speed can be prevented and the engine risk can be suppressed. On the other hand, when the engine speed is relatively high, the power generation torque is set to be relatively large, so that the engine speed can be decreased relatively early, for example, suppressing unnecessary engine blow-up. it can.

  That is, the control device of the present invention can achieve both avoidance of engine stall and drivability. Therefore, according to the control device of the present invention, when the accelerator-off is detected, the engine speed can be reduced at an appropriate speed, and the driver's feeling can be improved.

  Even if the engine speed when the accelerator-off is detected is the same (here, “one value”), the engine speed is increasing (ie, “the amount of change in the speed is a positive value”). It is desirable that the power generation torque be changed depending on whether the engine speed is decreasing (that is, “the amount of change in the engine speed is a negative value”).

  Specifically, for example, when a relatively large power generation torque is set due to a relatively high engine speed even though the engine speed is decreasing, an unexpected drop in the engine speed may occur. It can happen. On the other hand, if a relatively small power generation torque is set due to the low engine speed, even though the engine speed is increasing, it is difficult to suppress an unnecessary increase in the engine speed. there is a possibility.

  However, in the present invention, when the engine speed when the accelerator off is detected by the power generation control means is a single value and the amount of change in the speed is a positive value, the engine when the accelerator off is detected. The power generation torque is set larger than in the case where the rotational speed is the above-mentioned one value and the rotational speed change amount is a negative value.

Therefore, according to the control device of the present invention , the feeling of the driver can be further improved, which is very advantageous in practice.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a schematic structure figure showing the outline of the control device concerning an embodiment. It is a flowchart which shows the electric power generation control process which concerns on embodiment. It is an example of the torque map which prescribes | regulates the relationship between an engine speed, an engine speed change amount, and the torque of an alternator. It is a time chart which shows an example of time fluctuations, such as engine speed, when the power generation control processing concerning an embodiment is carried out.

  An embodiment according to a control device of the present invention will be described with reference to the drawings.

(Constitution)
The configuration of the control device according to the embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram illustrating an overview of a control device according to an embodiment.

  In FIG. 1, a vehicle on which a control device 100 is mounted includes an engine 11, an alternator 12 that generates electric power using rotational energy of the engine 11, an accelerator pedal 13, an ECU (Electronic Control Unit) 21, and It is configured with.

  The control device 100 includes an ECU 21, a crank angle sensor 22, and an accelerator position sensor 23. In the present embodiment, a part of the functions of the ECU 21 for various electronic controls of the vehicle is used as a part of the function of the control device 100.

  The ECU 21 as a part of the control device 100 calculates the rotational speed Ne and the rotational speed change amount ΔNe of the engine 11 based on the output signal of the crank angle sensor 22. Note that various known modes can be applied to the method of calculating the rotational speed Ne of the engine 11, and a detailed description thereof will be omitted. The rotational speed change amount ΔNe may be obtained by subtracting, for example, the rotational speed one sampling period before from the current rotational speed.

(Power generation control processing)
Next, power generation control processing performed by the control device 100 configured as described above will be described with reference to the flowchart of FIG. In the following description, it is assumed that the engine 11 is in operation.

  In FIG. 2, the ECU 21 as a part of the control device 100 first determines the presence or absence of an accelerator operation based on the output signal of the accelerator position sensor 23 (step S101). When it is determined that the accelerator is on (step S101: ON), the ECU 21 sets the power generation torque during a predetermined acceleration in the alternator 12 (step S104). The “power generation torque at the time of acceleration” is set as a value that can improve the fuel efficiency, and is typically smaller than the power generation torque at the time of accelerator off described later.

  On the other hand, when it is determined that the accelerator is off (step S101: OFF), the ECU 21 calculates the engine speed Ne and the engine speed change amount ΔNe based on the output signal of the crank angle sensor 22 (step S101). S102).

  Next, the ECU 21 specifies the torque related to the alternator 12 based on the calculated rotation speed Ne and the rotation speed change amount ΔNe and the torque map shown in FIG. 3, and sets the specified torque as the power generation torque. (Step S103).

  Here, the torque map will be described with reference to FIG. The equal torque line (curve) in FIG. 3 is an example, and the torque map includes an infinite number of equal torque lines.

  The torque map shown in FIG. 3 is constructed based on the following concept. That is, when the rotational speed Ne of the engine 11 is relatively high, the torque is set to be relatively large in order to reduce the rotational speed Ne relatively early. On the other hand, when the rotational speed Ne of the engine 11 is relatively low, the torque is set to be relatively small in order to avoid the engine risk. That is, the torque increases as the rotational speed Ne of the engine 11 increases. In other words, the torque decreases as the rotational speed Ne of the engine 11 decreases.

  Further, when looking at one rotation speed (see, for example, the rotation speed Ne1 in FIG. 3), when the rotation speed change amount ΔNe of the engine 11 is a positive value (that is, when the rotation speed of the engine 11 is increasing). ), The torque is larger than when the rotational speed change amount ΔNe is a negative value (that is, when the rotational speed of the engine 11 is decreasing). That is, at the same rotational speed, the torque increases as the rotational speed change amount ΔNe increases.

  Next, the effect of the control device 100 according to the embodiment will be described with reference to the time chart of FIG.

  It is assumed that the accelerator pedal is depressed by the driver (ie, the accelerator is turned on) at time t0 in FIG. 4, and the accelerator pedal depression by the driver is stopped (ie, the accelerator is turned off) at time t1. Since the inertial force works on the engine 11, even if the accelerator is turned off, the rotational speed Ne of the engine 11 increases for a while. At this time, if no measures are taken, the rotational speed Ne of the engine 11 continues to increase until, for example, time t2, as indicated by the broken line in FIG.

  On the other hand, in the present embodiment, as described above, when the accelerator is turned off, the power generation torque of the alternator 12 is set based on the rotational speed Ne of the engine 11 and the rotational speed change amount ΔNe. As a result, when the accelerator is turned off, a relatively large power generation torque is generated immediately (see “power generation torque” in FIG. 4). Then, the power generation torque becomes a load on the engine 11, and the rotational speed Ne of the engine 11 decreases relatively early (see “Ne” in FIG. 4).

  Note that the power generation torque decreases with time according to the rotational speed Ne of the engine 11 and the rotational speed change amount ΔNe (see particularly “time t1 to time t2” of “power generation torque” in FIG. 4).

  Thus, according to the control apparatus 100 which concerns on this embodiment, while being able to avoid an engine stall, drivability can be improved and a driver | operator's feeling can be improved.

  The “alternator 12”, “crank angle sensor 22” and “accelerator position sensor 23” according to the embodiments are examples of “power generation means”, “rotation speed detection means” and “accelerator operation detection means” according to the present invention, respectively. It is. The “ECU 21” according to the embodiment is an example of the “power generation control unit” and the “rotational speed change amount detection unit” according to the present invention, and is another example of the “rotational speed detection unit”.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. Moreover, it is included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 11 ... Engine, 12 ... Alternator, 13 ... Accelerator pedal, 21 ... ECU, 22 ... Crank angle sensor, 23 ... Accelerator pedal sensor, 100 ... Control apparatus

Claims (1)

  A vehicle control device comprising: an engine; and power generation means for generating electric power using rotational energy of the engine,
  A rotational speed detection means for detecting the rotational speed of the engine;
  An accelerator operation detecting means for detecting an accelerator operation related to the vehicle;
A rotational speed change detecting means for detecting the rotational speed change of the engine;
  When the accelerator operation is detected by the accelerator operation detecting means, the power generation control means for setting the power generation torque related to the power generation means to be larger as the detected rotational speed is higher;
  With,
The power generation control means detects that the accelerator off is detected when the detected rotational speed when the accelerator off is detected is a single value and the detected rotational speed change amount is a positive value. The power generation torque is increased so that the power generation torque is larger than that in the case where the detected rotation speed is the one value and the detected rotation speed variation is a negative value. Set
A control device characterized by that.

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