JP2005207416A - Engine speed controller, engine system, vehicle, and engine generator having it, and engine speed control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately control engine speed including engine speed in an idle state with a simple and inexpensive structure. <P>SOLUTION: A motor 160 for opening and closing a throttle valve 170 is PWM controlled. A target engine speed variation calculating section 220 calculates a target engine speed variation using an actual engine speed from an actual engine speed calculating section 210 and a target engine speed from a target rotation speed calculating section 260. A PWM pulse generating section 200b has a PWM micro pulse calculating section 240 and a PWM signal generating section 280. The PWM micro pulse calculating section 240 calculates at least one of a PWM duty correction value, a PWM duty correction value keeping time, and the number of PWM duty corrections in response to the target engine speed variation. The PWM signal generating section 280 transmits a PWM signal to the motor 160. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an engine speed control device and an engine speed control method for controlling the engine speed. Furthermore, the present invention relates to an engine, a system including the engine speed control device, a vehicle including the engine system, and an engine generator.

The engine speed in an idling state is susceptible to environmental conditions such as atmospheric pressure and temperature and is unstable. Thus, conventionally, ISC (Idle Speed Control) control is performed during idling in a vehicle equipped with an engine, particularly a motorcycle.
One prior art for ISC control is shown in US Pat. In this prior art, a throttle sensor that detects the opening (throttle opening) of a throttle valve disposed in the main intake passage of the engine is used. By controlling the throttle opening detected by the throttle sensor to the target opening, the idle speed is controlled.

In the idle speed range, the engine speed easily fluctuates due to slight changes in the intake air amount. Therefore, the throttle opening is detected with high resolution (approximately 0.02 degrees in throttle opening). It needs to be strictly controlled.
For example, the throttle sensor has a linear characteristic with an output value of 0 V at a throttle opening of 0 degrees and an output value of 5 V at a throttle opening of 90 degrees. However, when such an output signal of the throttle sensor is used after analog / digital conversion, for example, if an 8-bit A / D converter is used, the throttle opening per bit is 0.35 degrees, A sufficient resolution cannot be obtained.

Therefore, in the prior art disclosed in Patent Document 1, the throttle opening detection resolution in the low opening range is improved by amplifying the output signal of the throttle sensor with an amplifier and inputting it to the A / D converter. Yes.
Japanese Patent Laid-Open No. 5-263703

However, in the prior art of Patent Document 1, an amplifier is required to increase the detection resolution of the throttle opening.
SUMMARY OF THE INVENTION An object of the present invention is to provide an engine speed control device and an engine speed control method capable of accurately controlling the engine speed with a simple and inexpensive structure.

Another object of the present invention is to provide an engine system including the engine speed control device as described above.
Still another object of the present invention is to provide a vehicle including the engine system.
Still another object of the present invention is to provide an engine generator provided with the engine system.

  An engine speed control device according to the present invention includes a throttle valve that adjusts the amount of intake air taken into the engine, a drive unit that drives the throttle valve, and a control unit that generates a PWM signal for driving the drive unit. Including. The control unit includes an actual engine speed detection unit that detects an actual engine speed, a target engine speed setting unit that sets a target engine speed, an actual engine speed detected by the actual engine speed detection unit, Using the target engine speed set by the target engine speed setting unit, a target engine speed change amount calculating unit that calculates a target engine speed change amount, and a PWM for correcting the duty ratio of the PWM signal A PWM control parameter including at least one of a duty correction value, a PWM duty correction value maintenance time to which the PWM duty correction value should be continuously applied, and a PWM duty correction frequency to which the PWM duty correction value should be applied, Calculated according to the target engine speed change amount calculated by the target speed change amount calculation unit, the calculated And a PWM pulse generator to be transmitted to the driving unit generates a PWM signal based on WM control parameter.

  According to this configuration, the PWM control parameter including at least one of the PWM duty correction count, the PWM duty correction value, and the PWM duty correction value maintaining time is calculated according to the target engine speed change amount. Based on the PWM control parameter, the drive unit that drives the throttle valve is PWM-controlled. As a result, the throttle valve opening can be finely controlled not by feedback control based on the detection result of the throttle opening, but by feedforward control according to the target engine speed change amount, and the actual engine speed can be set to the target engine speed. The speed can be approached. In addition, it is possible to control the engine speed, particularly the idle speed that requires fine control, with a simple and cost-effective structure. Thereby, it is possible to perform fine control of the engine speed without requiring an amplifier for increasing the input resolution of the throttle sensor.

It is preferable that an initial value of the PWM control parameter is set in the PWM pulse generation unit. In this case, it is preferable that the initial value is set so that the minimum necessary driving force exceeding the static frictional force that prevents the displacement of the throttle valve is applied from the driving unit to the throttle valve.
According to this configuration, the displacement of the throttle valve can be caused by outputting the PWM signal using the initial value of the PWM control parameter as it is. As a result, the actual engine speed can be brought close to the target engine speed as desired, and in particular, the throttle valve can be opened and closed from the stationary state as desired even during idle speed control.

The PWM pulse generation unit may calculate the PWM control parameter using a function of the target engine speed change amount.
According to this configuration, since the PWM control parameter is calculated by a function corresponding to the target engine speed change amount, it can be quickly calculated from the target engine speed change amount.
The PWM pulse generation unit determines the PWM control parameter as a function of the target engine speed change amount calculated by the target speed change amount calculation unit and the actual engine speed detected by the actual speed detection unit. It may be calculated.

Thereby, not only the target engine speed change amount but also the actual engine speed can be considered, and the PWM control parameter can be determined more appropriately.
The PWM pulse generation unit calculates the PWM control parameter according to the target engine speed change amount calculated by the target speed change amount calculation unit, and based on the calculated PWM control parameter, You may provide the 1st control signal calculation part which calculates the 1st control signal for PWM control, and the signal generation part which produces | generates the said PWM signal sent to the said drive part. The engine speed control device further includes a throttle opening degree detecting unit that detects a throttle opening degree that is an opening degree of the throttle valve, and the target engine speed calculated by the target rotational speed change amount calculating unit. A target throttle opening change amount calculating unit for calculating a target throttle opening change amount from the change amount, and a target throttle opening amount using the target throttle opening change amount and the actual throttle opening detected by the throttle opening detecting unit; A target throttle opening calculation unit for calculating an opening; and the drive unit to bring the actual throttle opening detected by the throttle opening detection unit closer to the target throttle opening calculated by the target throttle opening calculation unit A second control signal calculating unit for calculating a second control signal for PWM control, and calculating the target throttle opening change amount And a selection unit that selects one of the first control signal and the second control signal based on the target throttle opening change amount calculated by the unit and outputs the selected signal to the signal generation unit. It may be. In this case, the signal generation unit may generate the PWM signal based on a control signal given from the selection unit.

  According to this configuration, it is possible to switch between feedback control that performs PWM control of the drive unit based on the throttle opening and feedforward control that performs PWM control of the drive unit based on the target engine speed change amount. As a result, appropriate control can be performed according to the situation, and high-speed control when the throttle opening is greatly changed is realized by feedback control, while high-definition control when the throttle opening is slightly changed is achieved. Can be compatible.

  More specifically, the selection unit is a selection determination value in which the target throttle opening change amount calculated by the target throttle opening change amount calculation unit is determined in advance based on an input resolution of the throttle opening detection unit. In the following cases, when the first control signal is selected and output to the signal generation unit, and the target throttle opening change amount calculated by the target throttle opening change amount calculation unit is larger than the selection determination value In addition, it is preferable that the second control signal is selected and output to the signal generation unit.

The selection determination value may be set to a value substantially equal to an input resolution of the throttle opening degree detection unit.
For example, if the selection determination value is set to be approximately equal to the input resolution of the throttle opening detection unit, the selection unit performs the first control when the target throttle opening change amount is smaller than the input resolution of the throttle opening detection unit. The first control signal from the signal calculation unit is selected, and the drive unit is driven through the signal generation unit. When the target throttle opening change amount is larger than the input resolution of the throttle opening detector, the second control signal is selected and the drive unit is driven via the signal generator. For this reason, engine speed control suitable for the situation can be performed.

That is, the engine speed can be finely controlled by PWM pulse control by selecting the first control signal, and if there is no need for fine engine speed control, the second control signal is selected and position feedback is performed. The engine speed control with a quick response can be performed by the control.
The selection unit selects the first control signal or the second control signal based on the actual throttle opening detected by the throttle opening detection unit in addition to the target throttle opening change amount. It may be output. Thereby, selection of a 1st control signal or a 2nd control signal is performed more appropriately.

  An engine speed control device according to an embodiment of the present invention includes an accelerator following target throttle opening calculation unit that calculates a target throttle opening based on an accelerator opening, and an actual throttle that is detected by the throttle opening detection unit. And a third control signal calculation unit that calculates a third control signal for PWM control of the drive unit so as to bring the opening closer to the target throttle opening calculated by the accelerator following target throttle opening calculation unit. . In this case, the selection unit is configured to perform the first throttle opening change based on the actual throttle opening detected by the throttle opening detection unit and the target throttle opening change calculated by the target throttle opening change calculating unit. It is preferable that one of the first control signal, the second control signal, and the third control signal is selected and output to the signal generation unit.

  According to this configuration, the first control signal corresponding to the PWM control parameter corresponding to the target engine speed change amount, the second control signal corresponding to the target engine speed change amount and the actual throttle opening, and the accelerator opening One of the corresponding third control signals is selected. As a result, it is possible to perform idle rotation control with high accuracy and to perform engine rotation speed control that satisfactorily follows the accelerator opening command.

  The selection unit selects and outputs the third control signal when the actual throttle opening detected by the throttle opening detection unit exceeds a predetermined threshold, and the actual throttle opening Is less than or equal to the threshold value, any one of the first control signal, the second control signal, and the third control signal is selected according to the target throttle opening change amount calculated by the target throttle opening change amount calculation unit. It is preferable that these are selected and output.

  According to this configuration, when the actual throttle opening is large, it is determined that the accelerator operation is being performed, and the third control signal corresponding to the accelerator opening is selected. As a result, engine speed control that responds to the accelerator operation at high speed becomes possible. On the other hand, when the actual throttle opening is relatively small, an appropriate one of the first, second, or third control signals can be selected in accordance with the target throttle opening change amount.

More specifically, the selection unit selects the third control signal when the target throttle opening change amount is larger than the first selection determination value, and selects the first selection determination value and the second selection determination value smaller than that. The second control signal may be selected when taking a value between 1 and 2, and the first control signal may be selected when the value is less than or equal to the second selection determination value.
The PWM pulse generation unit may repeatedly execute PWM correction control for sending a PWM signal corresponding to the PWM control parameter to the drive unit with a time interval. In this case, the engine speed control device detects the actual engine speed detected by the actual speed detector before a certain PWM correction control and the actual speed detector after the PWM correction control. An actual engine speed change amount calculating unit that calculates an actual engine speed change amount using the actual engine speed, and the target engine speed change amount calculated by the target engine speed change amount calculating unit, A change that changes the relationship between the target engine speed change amount and the PWM control parameter for the PWM correction control after the next time, using the actual engine speed change amount calculated by the actual speed change amount calculation unit. It is preferable to further comprise a part.

According to this configuration, when the throttle opening cannot be varied according to the target due to the PWM duty determined according to the previous PWM control parameter, the relationship between the PWM control parameter and the target engine speed change amount (For example, a function) is changed. Thereby, the throttle opening can be reliably changed from the next processing.
For example, the torque applied to the throttle valve driven by the drive unit is often not constant due to the influence of the friction of the throttle valve shaft, the gear backlash of the transmission mechanism of the throttle valve, the return spring, and the like. Therefore, if the initial value of the PWM control parameter is maintained, sufficient displacement of the throttle valve cannot be caused, and the engine speed may not be controlled with high accuracy. In this case, according to the above configuration, the actual change amount of the engine speed is fed back, and the change unit corrects the relationship between the PWM control parameter and the target engine speed change amount, thereby opening the throttle valve as desired. You can control the degree.

The changing unit further changes the relationship between the target engine speed change amount and the PWM control parameter by further adding the actual engine speed detected by the actual speed detecting unit before the PWM correction control. You may do.
The PWM pulse generation unit may execute the PWM correction control every predetermined control period.

When the absolute value of the actual engine speed change amount calculated by the actual engine speed change amount calculation unit is substantially zero, the changing unit is configured to change the PWM duty correction value with respect to the target engine speed change amount. It is preferable to change the relationship.
According to this configuration, the changing unit changes the relationship of the PWM duty correction value with respect to the target engine speed change amount when there is no substantial change in the actual engine speed change amount. Thereby, the displacement of the throttle valve can be surely caused, and the engine speed can be reliably controlled. When there is no change in the actual engine speed change amount, the throttle valve is not substantially displaced. That is, this is a case where the static friction torque is larger than the driving force of the driving unit when driving the throttle valve, for example, the motor generated torque. In such a case, even if the number of PWM duty corrections and the PWM duty correction value maintaining time are changed, the driving force generated by the drive unit does not change, which is not effective. Therefore, the throttle valve can be reliably driven by correcting the relationship between the PWM duty correction value and the target engine speed change amount.

  The changing unit has an absolute value of the actual engine speed change amount calculated by the actual engine speed change amount calculation unit that is not substantially zero, but is calculated by the target speed change amount calculation unit. When the difference from the absolute value of the target engine speed change amount exceeds a predetermined threshold value, the relationship between the PWM duty correction value maintaining time or the PWM duty correction frequency with respect to the target engine speed change amount is changed. It is preferable that

  According to this configuration, the changing unit, when the actual engine speed change amount is not zero but is much smaller than the target engine speed change amount, the PWM duty correction frequency or the PWM duty correction value maintaining time and the target Change the relationship with the engine speed change. As a result, the engine speed can be controlled more precisely than when the PWM duty correction value is corrected. Of course, even if the PWM duty correction value is changed, the actual engine speed change amount can be changed. However, for example, if the PWM duty correction value becomes too large, for example, the driving force (generated torque) generated by a drive unit such as a motor may become too large, and fine adjustment becomes difficult.

In addition, when the initial value of the PWM duty correction value is set so that the minimum driving force necessary for the throttle valve to start moving is generated from the drive unit, the PWM duty correction value is maintained and the PWM duty correction value is maintained. Fine adjustment of the throttle valve is easier when the number of times and the PWM duty correction value maintaining time are changed.
The engine system of the present invention includes an engine and an engine speed control device having the above-described features.

The vehicle of the present invention includes the engine system and traveling wheels that are rotationally driven by a driving force generated by the engine. With this configuration, it is possible to accurately control the engine speed especially at idling with an inexpensive configuration.
The engine generator according to the present invention includes the engine system and a power generation unit that operates using the engine as a drive source. With this configuration, the engine speed can be stabilized with high accuracy, and therefore an engine generator with a stable output can be realized with an inexpensive configuration.

  The engine speed control method of the present invention is a method of controlling the engine speed by driving a throttle valve by a drive unit driven by a PWM signal. The method includes: an actual engine speed detecting step for detecting an actual engine speed; a target engine speed setting step for setting a target engine speed; the detected actual engine speed; and the set target engine A target engine speed change amount calculating step for calculating a target engine speed change amount using the engine speed, and a PWM control parameter for determining a duty of the PWM signal as the calculated target engine speed change amount. A PWM control parameter calculation step that is calculated accordingly, and a PWM signal transmission step that generates a PWM signal based on the calculated PWM control parameter and transmits the PWM signal to the drive unit. The PWM control parameter applies a PWM duty correction value for correcting the duty ratio of the PWM signal, a PWM duty correction value maintaining time for which the PWM duty correction value should be continuously applied, and the PWM duty correction value. It includes at least one of the power PWM duty correction times.

  According to this method, the throttle valve is opened by feed-forward control for calculating the duty of the PWM signal based on the PWM control parameter target engine speed change amount for determining the duty of the PWM signal and driving the throttle valve based on the calculation result. The degree can be finely controlled. Thereby, it is possible to control the engine speed, particularly the idle speed that requires fine control, with a simple and inexpensive structure. Thereby, it is possible to perform fine control of the engine speed without requiring an amplifier for increasing the input resolution of the throttle sensor.

  The method further includes the step of setting the initial value of the PWM control parameter such that a minimum necessary driving force exceeding a static frictional force that prevents displacement of the throttle valve is applied from the driving unit to the throttle valve. It is preferable. As a result, the throttle valve can be reliably driven, so that the engine speed can be reliably changed.

In the PWM control parameter calculation step, it is preferable that the PWM control parameter is determined in consideration of not only the target engine speed change amount but also the actual engine speed.
Further, in a preferred embodiment of the method, a step of generating a first control signal based on the calculated PWM control parameter, and an actual throttle opening that is an opening of the throttle valve is detected by a throttle opening detector. A throttle opening degree detecting step, a target throttle opening degree calculating step for calculating a target throttle opening degree using the target engine speed change amount and the detected actual throttle opening degree, and the actual throttle opening degree as the target A step of calculating a second control signal for PWM control of the drive unit so as to approach the throttle opening. The PWM signal sending step generates a PWM signal based on the control signal selection step of selecting one of the first control signal and the second control signal, and the selected control signal, and the driving unit And sending to the network.

As a result, the throttle opening can be controlled more appropriately by combining the feedforward control based on the target engine speed change amount and the feedback control based on the detection result of the throttle opening.
In the control signal selection step, the first throttle opening change amount corresponding to the target engine speed change amount is less than or equal to a predetermined selection determination value based on an input resolution of the throttle opening detection unit. Preferably, the method includes a step of selecting a control signal and a step of selecting the second control signal when the target throttle opening change amount is larger than the selection determination value.

As a result, the control can be switched appropriately in accordance with the input resolution of the throttle opening detection unit, so that more appropriate throttle opening control can be performed.
The method further uses the detection results of the actual engine speed before and after the PWM correction control for sending a PWM signal corresponding to the PWM control parameter to the drive unit, to determine the actual engine speed change amount. The actual engine speed change amount calculating step, the target engine speed change amount and the actual engine speed change amount are used to calculate the target engine speed change amount and the PWM control for PWM correction control from the next time onward. And a step of changing a relationship with the parameter.

  Thereby, when the change of the actual engine speed is excessive or small, the setting mode of the PWM control parameter can be corrected, so that the engine speed can be reliably controlled.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram showing a configuration of an engine system according to the first embodiment of the present invention.
This engine system includes an engine (internal combustion engine) 120 and an engine speed control device 100. This engine system is mounted on a vehicle that controls the engine speed by, for example, adjusting the intake air amount to the engine by opening and closing an electronically controlled throttle valve. This electronically controlled throttle valve is controlled by PWM (Pulse Width Modulation). The engine speed control device 100 in this embodiment will be described as controlling the speed of the engine 120, particularly the speed of the engine 120 in an idle state in the vehicle.

  The engine speed control device 100 includes a crank angle sensor 110, a water temperature sensor 130, a motor (drive unit) 160, a throttle valve 170, and a control unit 180. The control unit 180 controls the opening (throttle opening) of the throttle valve 170 by generating a PWM signal for driving the motor 160. In this way, an electronically controlled throttle valve is configured.

The control unit 180 includes an actual engine speed calculation unit (actual speed detection unit) 210, a target engine speed setting unit 200a, a target engine speed change amount calculation unit (target speed change amount calculation unit) 220, and PWM minute pulse control. It has a table updating unit (changing unit) 250 and a PWM pulse generating unit 200b.
Crank angle sensor 110 detects the rotation angle of the crankshaft of engine 120 and outputs the detected signal to actual engine speed calculation unit 210.

The actual engine speed calculation unit 210 calculates the actual engine speed N based on the crank angle signal detected by the crank angle sensor 110, and uses the calculated actual engine speed N as the target engine speed change amount calculation unit 220. The result is output to the PWM pulse generation unit 200b and the PWM minute pulse control table update unit 250.
Moreover, the water temperature sensor 130 detects the water temperature of the cooling water that cools the engine 120, and outputs it to the target rotation speed setting unit 200a. The target rotation speed setting unit 200a includes a water temperature calculation unit 140 and a target engine rotation speed calculation unit 260.

The water temperature calculation unit 140 calculates the water temperature Twat based on the water temperature sensor signal input from the water temperature sensor 130, and outputs the water temperature Twat to the target engine speed calculation unit 260.
The target engine speed calculation unit 260 calculates a target engine speed N ^* as a target based on the water temperature Twat input from the water temperature calculation unit 140 and outputs the target engine speed change amount calculation unit 220 to the target engine speed change amount calculation unit 220.

Specifically, the target engine speed calculation unit 260 includes a storage unit _260m, and a function table in which the water temperature T _wat and the target engine speed N ^* are associated is stored in the storage unit _260m. Yes.
FIG. 2 shows an example of a function table stored in the storage unit 260m of the target engine speed calculation unit 260.

As shown in the function table f of FIG. 2, the target engine speed calculation unit 260 calculates a target engine speed N ^* n corresponding to the input water temperature Tn, and the target engine speed change amount calculation unit 220 and Output to the PWM minute pulse control table updating unit 250.
The target engine speed change amount calculation unit 220 is a deviation between the target engine speed N ^* calculated by the target engine speed calculation unit 260 and the actual engine speed N calculated by the actual engine speed calculation unit 210 ( It consists of a subtractor for calculating the engine speed deviation. In this embodiment, the target engine speed change amount calculation unit 220 outputs the calculated engine speed deviation as it is as the target engine speed change amount ΔN ^* (= N ^* −N). However, the target engine speed change amount calculation unit 220 may further perform a predetermined calculation on the engine speed deviation to obtain the target engine speed change amount ΔN ^* .

The target engine speed change amount calculation unit 220 outputs the calculated target engine speed change amount ΔN ^* to the PWM pulse generation unit 200b and the PWM minute pulse control table update unit 250.
The PWM pulse generation unit 200 b includes a PWM minute pulse calculation unit 240 and a PWM signal generation unit 280. The PWM signal generation unit 280 includes a PWM signal that drives the motor 160 in a direction to open the throttle valve 170 (open direction), a PWM signal that drives the motor 160 in a direction to close the throttle valve 170 (close direction), and a throttle valve. A PWM signal holding the position of 170 can be generated. More specifically, for example, the position of the throttle valve 170 can be held by applying a PWM pulse having a predetermined holding duty ratio to the motor 160, and thus the throttle opening can be held. Further, for example, by applying a PWM pulse having a duty ratio larger than the holding duty ratio to the motor 160, the motor 160 can be driven in the opening direction, and the throttle opening can be increased. Further, for example, by applying a PWM pulse having a duty ratio smaller than the holding duty ratio to the motor 160, the motor 160 can be driven in the closing direction, and the throttle opening can be reduced. Of course, various known methods can be applied to the control method of the motor 160 by the PWM signal.

On the other hand, the PWM minute pulse calculation unit 240 has a target engine speed change amount ΔN ^* calculated by the target engine speed change amount calculation unit 220 and an actual engine speed N calculated by the actual engine speed calculation unit 210. From this, a parameter (PWM control parameter) for PWM minute pulse control is calculated. The PWM minute pulse calculation unit 240 further outputs a PWM duty (control signal) based on the calculated PWM control parameter to the PWM signal generation unit 280.

Here, the PWM minute pulse refers to individual pulses constituting the PWM pulse train. The PWM minute pulse control is a control (PWM correction control) for correcting the PWM pulse to finely move the throttle valve 170 from a state where the PWM pulse having the holding duty ratio is applied to the motor 160. Shall.
The PWM minute pulse calculation unit 240 has function tables h1, h2, and h3 for determining PWM control parameters. In this embodiment, the PWM control parameters calculated according to the target engine speed change amount ΔN ^* and the actual engine speed N are the PWM duty correction count n _pwm , the PWM duty correction value Δduty, and the PWM duty correction value maintaining time. Includes t _pwm . Therefore, the function tables h1, h2, and h3 are based on the input target engine speed change amount ΔN ^* and the actual engine speed N, respectively, and the PWM duty correction number n _pwm , the PWM duty correction value Δduty, and the PWM duty correction. The value maintenance time t _pwm is generated.

The PWM minute pulse calculation unit 240 obtains the duty ratio of the PWM minute pulse based on the PWM duty correction number n _pwm , the PWM duty correction value Δduty, and the PWM duty correction value maintenance time t _pwm , and uses this as a control signal as a PWM signal generation unit 280.
FIG. 3 is a diagram for explaining parameters in the PWM minute pulse control. FIG. 3 shows an example in which the number of PWM duty corrections is two, and further shows PWM control parameters and corresponding PWM signals (voltages).

The PWM minute pulse control is repeatedly executed every predetermined control cycle. The PWM minute pulse calculation unit 240 sets a PWM duty for the PWM signal generation unit 280 for each predetermined duty setting cycle TD in each control cycle, and the PWM signal generation unit 280 sets a PWM having a duty corresponding thereto. Generate a signal.
For example, the PWM duty Da is a holding duty ratio (a constant value) for maintaining the current throttle opening, and the PWM duty Db is an example of a duty ratio for driving the throttle valve 170 in the opening direction. The duty Dc is an example of a duty ratio for driving the throttle valve 170 in the closing direction. In this case, the deviation of the PWM duties Db and Dc from the PWM duty Da is the PWM duty correction value Δduty. The PWM duty correction value Δduty is a positive value when a PWM duty Db larger than the PWM duty Da is set, and a negative value when a PWM duty Dc smaller than the PWM duty Da is set.

In the example shown in FIG. 3, the PWM duty is increased from Da to Db twice with a time interval of the duty setting period TD. That is, the PWM duty correction number n _pwm = 2 which is the number of times the PWM duty correction value Δduty is applied. Further, the PWM duty Db is maintained over the PWM duty correction value maintenance time t _pwm that is the time for which the PWM duty correction value Δduty should be continuously applied.

4 (a), 4 (b) and 4 (c) are diagrams showing the relationship between the PWM control parameter and the target engine speed change amount, and FIG. 4 (a) shows the PWM duty correction count n. A function table (function h1) showing the relationship between _pwm , target engine speed change amount ΔN ^*, and actual engine speed N is shown. FIG. 4B shows a function table function h2 indicating the relationship between the PWM duty correction value Δduty, the target engine speed change amount ΔN ^*, and the actual engine speed N. Further, FIG. 4C shows a function table (function h3) showing the relationship between the PWM duty correction value maintaining time t _pwm , the target engine speed change amount ΔN ^*, and the actual engine speed N.

The function h1 shown in FIG. 4A is n _pwm = INT (h ₁ a | ΔN ^* | + h ₁ b) (where h ₁ a and h ₁ b are coefficients), and the PWM duty correction count (n _pwm ) appears discretely. Also, depending on the value of the actual engine speed N, the coefficient h ₁ a, at least one of h ₁ b (h ₁ b in the example of FIG. 4 (a)) is defined to a different value.
The function h2 shown in FIG. 4B has Δduty = h ₂ a (ΔN ^* ) + h ₂ b (when ΔN> 0, where h ₂ a and h ₂ b are coefficients), Δduty = 0 (ΔN = 0)), Δduty = h ₂ a (ΔN ^* ) − h ₂ b (when ΔN <0), and the PWM duty correction value Δduty continuously with respect to the target engine speed change amount ΔN ^* . It is set up. Also, depending on the value of the actual engine speed N, the coefficient h ₂ a, at least one of h ₂ b (h ₂ b in the example of FIG. 4 (b)) is defined to a different value.

Actually, the function table h2 stores only the PWM duty correction value Δduty when ΔN ≧ 0, and when ΔN <0, the PWM duty correction value Δduty (| ΔN | stored in the function table h2 is stored. The PWM duty is corrected by using a value obtained by adding a negative sign to the value corresponding to.
The function h3 shown in FIG. 4C is t _pwm = h ₃ a | ΔN ^* | + h ₃ b (where h ₃ a and h ₃ b are coefficients), and the PWM duty correction value maintaining time t _pwm is The engine speed change amount ΔN ^* is set continuously. Also, depending on the value of the actual engine speed N, the coefficient h ₃ a, at least one of h ₃ b (h ₃ b in the example of FIG. 4 (c)) is defined to a different value.

As will be described later, coefficients h ₁ a, h ₂ a, h ₃ a, h ₁ b, which define the functions h ₁ , h ₂ , h ₃ shown in FIGS. 4 (a), 4 (b) and 4 (c), h ₂ b and h ₃ b are variables and can be updated. These coefficients h ₁ a, h ₂ a, h ₃ a, h ₁ b, h ₂ b, h ₃ b are updated by the function update data of the PWM minute pulse control table update unit 250.
In the function tables h1, h2, and h3, for example, only function values for a plurality of predetermined engine speeds N (N = 1000, 1200, 1400 in the examples of FIGS. 4A to 4C) are stored. Has been. When the engine speed N is other than these, interpolation of the function values stored in the function tables h1, h2, and h3 may be performed to determine each PWM control parameter, or the engine speed approximated to the actual engine speed A numerical function value may be used as the PWM control parameter.

In the PWM minute pulse calculation unit 240, initial values of the PWM control parameters n _pwm , Δduty, and t _pwm are set. This initial value is set such that a torque exceeding the static friction torque applied to the motor 160 to be driven (a necessary minimum level) is generated from the motor 160.
Here, setting of initial values of PWM control parameters n _pwm , Δduty and t _pwm (specifically, initial values of coefficients h ₁ b, h ₂ b, h ₃ b of functions h ₁ , h ₂ , h ₃ ) This will be described with reference to FIGS. 5 (a) and 5 (b) and FIGS. 6 (a) to 6 (d).

  FIG. 5A is a schematic diagram showing the structure of the throttle valve 170, and FIG. 5B is a diagram showing the friction torque applied to the motor 160 shown in FIG. 5A. As shown in FIG. 5A, the motor 160 is provided on a throttle body 161 connected to the intake pipe of the engine 120. The throttle body 161 is further provided with a transmission mechanism 162 composed of a plurality of gears and a throttle valve 170 for opening and closing an intake passage 161a connected to the intake pipe. The throttle valve 170 is rotatably supported by the throttle body 161 via the shaft portion 163. The rotational force from the transmission mechanism 162 is transmitted to the shaft portion 163 of the throttle valve 170.

The rotating shaft of the motor 160 is connected to the transmission mechanism 162, and the shaft portion 163 of the throttle valve 170 is rotated via the transmission mechanism 162. The opening of the throttle valve 170 (throttle opening) is adjusted by the rotation of the shaft portion 163.
Friction torque is applied to the motor 160 from the shaft mounting portion of the throttle valve 170 (the portion f1 in FIG. 5A) and the mechanism inside the motor 160.

As shown in FIG. 5B, the friction torque applied to the motor 160 is the largest when the motor 160 is stationary, and decreases once the motor 160 starts to move. Therefore, the initial value Δduty _i (= h ₂ b) of the PWM duty correction value Δduty in the function h2 is approximately determined by the following (Expression 1) to (Expression 3).
E (V) = (Da + Δduty _i ) (%) × E _in (V) / 100 (Equation 1)
However, E _in the inter-terminal voltage of the motor 160, Da is the PWM duty when the throttle opening holding, E is a voltage substantially applied to the motor 160 by the PWM control.

I (A) = E (V) / R (Ω) (Formula 2)
Where I is the motor armature current and R is the motor armature resistance.
I (A) × K _T > Tm (Formula 3)
Here, _KT is a motor torque constant, and Tm is a friction torque applied to the motor 160 when stationary.

Basically, the static friction torque Tm is regarded as a constant, and the initial value of the PWM control parameter (here, the initial value of the PWM duty correction value Δduty = h ₂ ) based on the above (Expression 1) to (Expression 3). an initial value of b) is set. However, in the configuration of the throttle body 161, there is a gap (gear backlash) portion gb between the gears of the transmission mechanism 162. Therefore, in practice, the initial value calculated by the above (Expression 1) to (Expression 3) does not necessarily cause the throttle valve 170 to slightly move.

  On the other hand, a time lag occurs between the change in PWM duty and the change in motor current I. FIGS. 6A to 6D are diagrams showing the behavior of the PWM duty and the motor current. 6A shows the time change of the PWM duty, FIG. 6B shows the time change of the motor current I, FIG. 6C shows the time change of the actual throttle opening, and FIG. Indicates the time variation of the actual engine speed.

As shown in FIGS. 6A and 6B, there is a delay from when the PWM duty is changed to when the motor current I actually changes. Further, the throttle opening changes with a delay (see FIG. 6C), and the actual engine speed changes with a slight delay.
The response delay of the motor current I can be expressed by an electrical time constant Te (time to reach 63.2% of the final value) shown by the following (formula 4).

Electrical time constant: Te (s) = L (H) / R (Ω) (Formula 4)
However, L is motor inductance.
The PWM duty correction value maintaining time t _pwm to which the PWM duty correction value Δduty is continuously applied is desirably shortened, and the PWM duty correction number n _pwm is preferably as small as possible. For this reason, when setting the initial values of PWM control parameters (the initial values of the coefficients h ₁ b, h ₂ b, h ₃ b), the motor current is calculated using (Equation 1) to (Equation 4) Considering the delay in the behavior of I, among the PWM control parameters, the initial values of the PWM duty correction value maintaining time t _pwm and the PWM duty correction frequency n _pwm are set as small as possible.

Note that the operation examples shown in FIGS. 6A to 6D are operations when the throttle valve 170 is slightly driven, such as during idling speed control. In this operation example, the PWM minute pulse calculation unit 240 generates a PWM duty (control signal) corresponding to a PWM duty correction value Δduty that generates a torque necessary to overcome the friction torque at rest (see FIG. 5B). As soon as the PWM duty correction value maintaining time t _pwm elapses after the throttle valve 170 starts driving, the PWM duty before correction (holding duty ratio) is output.

The PWM minute pulse calculation unit 240 corrects the function h3 to the function h3 based on the function update data input from the PWM minute pulse control table update unit 250.
The PWM minute pulse control table update unit 250 includes a target engine speed change amount ΔN ^* calculated by the target engine speed change amount calculation unit 220 and an actual engine speed N calculated by the actual engine speed calculation unit 210. Are entered.

The PWM minute pulse control table updating unit 250 includes a storage unit 250m that stores the actual engine speed N that is input. The storage unit 250m stores the actual engine speed N _old calculated by the actual engine speed calculation unit 210 before the execution of the PWM minute pulse control in the current control cycle. The PWM minute pulse control table updating unit 250 obtains a deviation between the actual engine speed N _old stored in the storage unit 250m and the actual engine speed N after being changed by the PWM minute pulse control in the current control cycle. The deviation is the actual engine speed change amount ΔN (= N−N _old ). However, the deviation from the actual engine speed before and after the PWM minute pulse control in the current control cycle is not directly used as the actual engine speed change amount ΔN, but is applied to each actual engine speed before and after the PWM minute pulse control. The actual engine speed change amount ΔN may be obtained by performing a certain calculation.

  The PWM minute pulse control table updating unit 250 further has a function of generating function update data for updating the function tables h1, h2, and h3 of the PWM control parameters of the PWM minute pulse calculating unit 240. The PWM minute pulse control table updating unit 250 creates function update data based on each input information, and outputs this function update data to the PWM minute pulse calculation unit 240.

The function update data is a value that offsets the values of the functions h1 to h3 of the PWM minute pulse calculator 240 by a predetermined value. Specifically, function update data is used to increase or decrease the coefficients h ₁ b, h ₂ b, h ₃ b of the functions h ₁ , h ₂ , h ₃ . This function update data may be data for increasing or decreasing the coefficients h ₁ a, h ₂ a, h ₃ a of the functions h ₁ , h ₂ , h ₃ , and the coefficients h ₁ a, h ₂ a, h ₃ a and Data for increasing / decreasing both of the coefficients h ₁ b, h ₂ b, and h ₃ b can also be used. Of course, it is not always necessary to change the function values for all the functions h1, h2, and h3. For example, only the value of the function h2 for determining the PWM duty correction value Δduty may be increased or decreased according to the function update data. Good.

When the function update data is given to the PWM minute pulse calculation unit 240 and the function value is offset, the functions h1, h2, and h3 for obtaining the PWM control parameter are substantially changed. Specifically, even if the PWM minute pulse control is performed in which the PWM duty correction control in which the PWM duty correction value Δduty is applied over the maintenance time t _pwm is performed over the correction number n _pwm , the actual engine speed change amount ΔN When the deviation from the target engine speed change amount ΔN ^* is large, the functions h1, h2, and h3 are updated. That is, function update data for offsetting the function value is provided from the PWM minute pulse control table updating unit 250 to the PWM minute pulse calculating unit 240. As a result, the PWM control parameters are determined by the updated functions h1, h2, and h3 at the time of the PWM minute pulse control in the next control cycle, so that the engine speed can be changed as desired.

Before the functions h1, h2, and h3 are updated, the PWM control parameters are determined according to the initial values of the coefficients h ₁ b, h ₂ b, and h ₃ b.
The PWM signal generation unit 280 stores the PWM duty input from the PWM minute pulse calculation unit 240 in the storage unit (register) 280m, and generates a PWM signal based on the PWM duty (control signal) stored in the storage unit 280m. It is generated and output to the motor 160.

The motor 160 is provided in the throttle body 161 as described above, and is driven based on the PWM signal from the PWM signal generation unit 280 to change the angle (opening) of the throttle valve 170. As the angle of the throttle valve 170 changes, the throttle opening changes, the intake air amount changes, and the engine speed changes.
FIG. 7 is a flowchart showing the operation of the engine speed control device according to this embodiment. The process shown in FIG. 7 is repeatedly executed every predetermined control cycle.

First, the water temperature calculation unit 140 calculates a water temperature T _wat based on input from the water temperature sensor 130, based on the water temperature T _wat, target engine speed calculating section 260 calculates the target engine speed N ^* (Step S1).
In step S2, the target engine speed change amount calculation unit 220 subtracts the actual engine rotational speed N from the target engine speed N ^*, calculates the target engine speed change amount ΔN ^* (= N ^* -N) . Further, the PWM minute pulse control table updating unit 250 stores the actual engine speed N calculated by the actual engine speed calculating unit 210 in the storage unit 250m as the actual engine speed recorded value N _old . The actual engine speed record value N _old is used as the actual engine speed before adjusting the throttle opening by the PWM minute pulse control in the process in step S9 described later. This actual engine speed recorded value N _old corresponds to the result of the PWM minute pulse control in the previous control cycle.

Next, in step S3, the PWM minute pulse calculation unit 240 calculates a PWM control parameter from the target engine speed change amount ΔN ^* and the actual engine speed N. That is, the PWM minute pulse calculation unit 240 obtains the PWM duty correction number npwm by the function h1, obtains the PWM duty correction value Δduty by the function h2, and obtains the PWM duty correction value maintenance time t _pwm by the function h3.

Next, in step S4, the PWM minute pulse calculation unit 240 clears the count value i of the counter that counts the PWM duty correction count n _pwm .
In step S5, the PWM minute pulse calculation unit 240 performs the holding duty ratio (in FIG. 3) by the PWM duty correction value Δduty calculated in step S3 during the PWM duty correction value maintaining time t _pwm calculated in step S3. From Da), the PWM duty is corrected to increase or decrease.

Next, in step S6, the PWM minute pulse calculation unit 240 adds 1 to the count value i of the PWM duty correction number counter. Further, in step S7, the PWM minute pulse calculator 240 determines whether or not the PWM duty correction count has reached the PWM duty correction count n _pwm calculated in step S4 (i ≧ n _pwm ).
If the PWM duty is corrected by the PWM duty correction number n _pwm (i ≧ n _pwm ), the process _{proceeds to} step S9, and if the correction for the PWM duty correction number n _pwm is not completed (i <n _pwm ), the process _{proceeds to} step S8.

In step S8, the PWM minute pulse calculation unit 240 determines that the deviation of the current actual engine speed N from the target engine speed N ^* (= | N ^* −N |. Engine speed deviation) is within an allowable range (engine speed). It is determined whether the deviation is less than the allowable value Nα, where Nα> 0). If the engine speed deviation amount | N ^* −N | is equal to or greater than the engine speed deviation allowable value Nα, the PWM minute pulse calculating unit 240 returns to step S5 and repeats the process, and if the engine speed deviation allowable value Nα is less than If there is, the process proceeds to step S9.

In this way, until the PWM duty correction reaches the PWM duty correction count n _pwm or the actual engine speed N is sufficiently close to the target engine speed N ^* , a predetermined condition is satisfied. It will be repeated with a time interval. The reason why the PWM duty correction is repeatedly performed at such a time interval is that there is a time lag from the correction of the PWM duty until the actual engine speed changes as described with reference to FIG.

In step S9, the PWM minute pulse control table update unit 250 stores the actual engine speed N after finishing the PWM minute pulse control in the current control cycle (YES in step S7 or S8) and before this PWM minute pulse control. The actual engine speed change amount ΔN (= N−N _old ) is calculated from the actual engine speed record value N _old recorded in the section 250m.
Next, in step S10, the PWM minute pulse control table updating unit 250 updates the PWM minute pulse control parameter functions h1 to h3 based on the target engine speed change amount ΔN ^* and the actual engine speed change amount ΔN. The function update process is executed. The target engine speed N ^* may be further added to this function update process.

When the function update data is output by the function update process, the PWM minute pulse calculation unit 240 offsets the function values of the functions h1, h2, and h3 according to the function update data.
The above processing is repeatedly executed every control cycle.
FIG. 8 is a flowchart showing the updating process of the PWM minute pulse control parameter function performed in step S10 of FIG.

In this process, first, in step S10-1, based on the actual engine speed change amount ΔN calculated in step S9 (see FIG. 7) and the target engine speed change amount ΔN ^* calculated in step S2. The PWM minute pulse control table updating unit 250 calculates a difference Nh (= | ΔN ^* | − | ΔN |) (engine speed variation variation deviation) between the absolute values of the variation amounts.

  Next, in step S10-2, the PWM minute pulse control table updating unit 250 determines that the calculated engine speed change amount deviation Nh is a preset function value for updating the PWM minute pulse control Nβ (> 0, constant value). ) It is determined whether it is larger. If engine speed variation deviation Nh is larger than determination value Nβ, the process proceeds to step S10-4. If engine speed variation deviation Nh is equal to or smaller than determination value Nβ, the process proceeds to step S10-3. Transition.

When the engine speed change amount deviation Nh exceeds the determination value Nβ (YES in step S10-2), the actual engine speed N does not vary sufficiently even though the PWM minute pulse control is performed. It is. In this case, in step S10-4, the PWM minute pulse control table updating unit 250 outputs function update data for increasing the output value of the parameter function so that the throttle valve 170 moves more than before. Then, the function update process is terminated. In step S10-4, as an example, function update data instructing to increase the coefficient h ₂ b of the function h2 by the shift amount b1 (b1> 0) is output. As a result, the function value of the function h2 for calculating the PWM duty correction value Δduty is uniformly increased by the shift amount b1.

The shift amount b1 may be a constant value, or may be variably set according to the engine speed change amount deviation Nh. When the shift amount b1 is determined in accordance with the engine speed change amount deviation Nh, it is preferable to determine the shift amount b1 within a predetermined upper limit value or less in order to prevent an abrupt engine speed change.
The processing timing when the actual engine speed change amount | ΔN | is smaller than the target engine speed change amount | ΔN ^* | (| ΔN ^* | − | ΔN |> Nβ) is shown in FIGS. It is shown in (b) and FIG.

FIG. 9 is a diagram showing the processing timing of the engine speed control device according to this embodiment, and shows the behavior of the water temperature and the target engine speed.
10 (a) and 10 (b), when the change in the actual engine speed is smaller than the target at the processing timing when the water temperature T _wat is increasing as shown in FIG. 9 (| ΔN ^* | − | It is a figure which shows the timing of control of the engine speed of ((DELTA) N |> N (beta)). FIG. 10A shows the change of the engine speed, and FIG. 10B shows the PWM duty corresponding to the change of the engine speed of FIG. FIG. 11 shows the relationship between the target engine speed N ^* and the actual engine speed N in the control cycle PC of FIG. 9, FIG. 10 (a), FIG. 10 (b), and FIG. 11 also show the execution timing of the main steps in the flowchart of FIG. 7.

In the example of FIG. 10A, in step S10 in a certain control cycle PC, the function h2 is updated (in this example, h ₂ b is updated by increasing the shift amount b1), and then the portion indicated by the arrow a is displayed. As can be seen, the change in the engine speed is almost achieved.
In other words, in the control cycle PC, the PWM duty is corrected to be decreased three times by the processes in steps S3 to S8. As a result, the throttle valve 170 is driven in the closing direction by the motor 160, and the throttle opening is reduced. As a result, the actual engine speed N is reduced. However, the actual engine speed change amount | ΔN | is small, and the difference between the actual engine speed N and the target engine speed N ^* is large. Therefore, the function h2 is updated in step S10 in the control cycle PC.

In the next control cycle PC01, the PWM duty correction value Δduty is obtained and applied based on the updated function h2. As a result, the PWM duty is corrected three times by the negative PWM duty correction value Δduty having a large absolute value. Then, as indicated by the arrow a, the actual engine speed N approaches the target engine speed N ^* .
On the other hand, in step S10-3 of FIG. 8, the PWM minute pulse control table updating unit 250 determines that the engine speed variation deviation Nh calculated in step S10-1 is a predetermined determination value “−Nβ” (negative It is determined whether it is smaller than a certain value. If the engine speed variation deviation Nh is greater than or equal to the determination value “−Nβ”, the function update process is terminated. That is, when the target engine speed change amount (ΔN ^* ) and the actual engine speed change amount (ΔN) are substantially the same, the function is not updated.

  12 (a) and 12 (b) are diagrams showing the control timing of the engine speed when the change in the actual engine speed is substantially as intended. FIG. 12 (a) shows the engine speed. FIG. 12B shows the PWM duty corresponding to the engine speed change shown in FIG. FIG. 13 is a diagram showing the relationship between the target engine speed and the actual engine speed in the control cycle PC1 of FIG. FIGS. 12A, 12B, and 13 also show the timings of the main steps of the flowchart shown in FIG.

As shown by the arrow b in FIG. 12A, when the difference between the target engine speed change amount | ΔN ^* | and the actual engine speed change amount | ΔN | is small, the PWM parameter function need not be updated. By repeating a series of control processes, the difference between the actual engine speed N and the target engine speed N ^* is eliminated. As a result, the actual engine speed N converges to the target engine speed N ^* .
More specifically, in the control cycle PC1, as shown in FIG. 12B, the PWM duty is corrected to decrease over three times. As a result, the motor 160 drives the throttle valve 170 in the closing direction, and as a result, the throttle opening is reduced, and the actual engine speed N is reduced to near the target engine speed N ^* . Therefore, the parameter function is not updated in step S10 in the control cycle PC1.

In the control cycle PC11 next to the control cycle PC1, the PWM duty reduction correction is performed once, whereby the actual engine speed N is substantially equal to the target engine speed N ^* as indicated by the arrow b. . In the example of FIG. 12B, the absolute value of the PWM duty correction value Δduty in the control cycle PC11 next to the control cycle PC1 is smaller than the absolute value of the PWM duty correction value Δduty in the control cycle PC1. The number of PWM duty corrections is also decreasing. This corresponds to a decrease in the target engine speed change amount ΔN ^* . In addition to this, the PWM duty correction value maintenance time t _pwm may also be reduced.

When the actual engine speed changes slightly, the motor-generated torque necessary to finely move the throttle valve 170 is obtained, so there is no need to change the PWM duty correction value Δduty, and the function h2 There is no need to update.
In step S10-3 of FIG. 8, if the engine speed change amount deviation Nh is smaller than the determination value “−Nβ”, the process proceeds to step S10-5.

In this case, the actual engine speed change amount ΔN is larger than the target engine speed change amount ΔN ^* , and the engine speed N has changed excessively. Therefore, the PWM minute pulse control table updating unit 250 reduces the output value of the parameter function so that the throttle valve 170 moves smaller than before. That is, function update data for decreasing and correcting the output value of the function is output to the PWM minute pulse calculator 240, and the parameter function update process is terminated.

In the example of FIG. 8, in step S10-5, the PWM minute pulse control table update unit 250 decreases the value of the coefficient h ₂ b of the function h2 for calculating the PWM duty correction value by the shift amount b2 (> 0). Thus, the output of the function h2 is corrected to decrease. The shift amount b2 may be a constant value, or may be variably set according to the engine speed change amount deviation Nh. When the shift amount b2 is determined in accordance with the engine speed change amount deviation Nh, it is preferable to determine the shift amount b2 within a predetermined upper limit value or less in order to prevent a sudden engine speed change.

  14 (a) and 14 (b) are diagrams showing the control timing of the engine speed when the actual engine speed change is larger than the target, and FIG. 14 (a) shows the engine speed. FIG. 14B shows a PWM duty corresponding to the engine speed change shown in FIG. 14A. FIG. 15 is a diagram showing the relationship between the target engine speed and the actual engine speed in the control cycle PC2 of FIG. 14A, 14B, and 15 also show the execution timings of the main steps in the flowchart of FIG.

As shown in FIG. 14A, after updating the function h2 (updating the coefficient h2b by the shift amount b2) in step S10 in the control cycle PC2, as seen in the part indicated by the arrow c, The engine speed change is almost as expected.
More specifically, the PWM duty reduction correction is performed three times in the control cycle PC2. As a result, the actual engine speed N fluctuates excessively, and the actual engine speed change amount | ΔN | is much larger than the target engine speed change amount | ΔN ^* |. Therefore, the parameter function h2 is updated by the process of step S10 in the control cycle PC2.

Thus, in the next control cycle PC21, the PWM duty increase correction (Δduty> 0) is performed three times, and the actual engine speed N becomes the target engine speed N ^{* as} indicated by the arrow c ^. Is almost equal to
In the flowchart shown in FIG. 8, the case where the function h2 of the duty correction value Δduty is updated is described as the process of updating the parameter function. However, the functions h1 and h3 may be updated in the same manner.

FIG. 16 is a flowchart illustrating another example of the parameter function update process.
As an example of a case where the PWM duty is increased only by the correction value Δduty in step S10-4 of FIG. 8 described above, when there is no actual engine speed change, that is, the actual engine speed change amount | ΔN | -N _old | = 0 in some cases. When the actual engine speed change amount ΔN is 0, the throttle valve 170 driven by the motor 160 is inoperative, and the motor generated torque is considered to be smaller than the stationary friction torque (see FIG. 5B). . Therefore, the generated torque does not change even if the PWM duty correction number n _pwm or the PWM duty correction value maintaining time t _pwm is changed. That is, in order to increase the motor generated torque and move the throttle valve 170, it is necessary to change the PWM duty correction value Δduty.

Therefore, in the example shown in FIG. 16, the PWM minute pulse control table updating unit 250 determines whether or not the actual engine speed change amount | ΔN | is 0 (step S10-11). If | ΔN | = 0, the PWM minute pulse control table updating unit 250 increases the function value of the function h2 (increases in the region of ΔN ^* > 0 and decreases in the region of ΔN ^* <0). The function update data is given to the PWM minute pulse calculation unit 240 to substantially update the function h2 (step S10-12).

When the actual engine speed change amount | ΔN | is not 0 (NO in step S10-11), but the difference from the target engine speed change amount | ΔN ^* | is large, that is, | N | ≠ 0. In some cases, | Nh |> β (where Nh = | ΔN ^* | − | ΔN |, β >> Nβ) (step S10-13). More specifically, this is the case where the actual engine speed change amount | ΔN | is much smaller than the target engine speed change amount | ΔN ^* | (insufficient PWM duty correction).

In such a case, the PWM minute pulse control table updating unit 250 updates the function h1 that defines the PWM duty correction number n _pwm or the function h3 that defines the PWM duty correction value maintaining time t _pwm. Is given to the PWM minute pulse calculator 240 (step S10-14). Thereby, the actual engine speed change amount ΔN in the PWM minute pulse control of the next control cycle can be increased.

Even if the function h2 for determining the PWM duty correction value Δduty is updated, the actual engine speed change amount ΔN can be increased or decreased. However, if the PWM duty correction value Δduty is too large, the generated torque becomes excessive and fine adjustment of the drive amount may be difficult. If it is too small, the throttle valve 170 may not be operated.
Furthermore, as described above, the initial value of the PWM duty correction value Δduty is set so that the motor 160 generates the minimum required torque for the throttle valve 170 to start moving. Therefore, if the actual engine speed change amount | ΔN | is not 0, the initial value of the PWM duty correction value Δduty is maintained as it is, and the PWM duty correction frequency n _pwm or the PWM duty correction value maintenance time t _pwm is changed. It is easier to finely adjust the drive amount of the throttle valve 170 when this is done.

Note that the determination of whether or not the actual engine speed change amount | ΔN | in step S10-11 is 0 is a determination of whether or not the actual engine speed change amount | ΔN | Therefore, this determination may be replaced with, for example, a determination as to whether the actual engine speed change amount | ΔN | is equal to or smaller than a small constant α (> 0).
When the PWM duty correction count n _pwm is 2 or more, it is preferable to leave some time intervals between the duty-corrected micro pulse trains. Thus, the relationship between the PWM duty correction number n _pwm and the actual engine speed change amount ΔN (= N−N _old ) is substantially proportional.

In this case, for example, if the PWM duty correction number n _pwm is 1 and the actual engine speed change amount ΔN is 5 rotations, the PWM engine speed correction number n _pwm is 2 times. The amount of change ΔN can be expected to be approximately 10 revolutions. Thus, if the PWM minute pulse control is performed by changing the PWM duty correction frequency n _pwm , it is easy to predict the actual engine speed change amount ΔN.

Even when the PWM minute pulse control is performed by changing the PWM duty correction value maintaining time t _pwm , it is preferable to leave a certain time interval between the duty-corrected minute pulse trains. However, the relationship between the PWM duty correction value maintaining time t _pwm and the actual engine speed change amount ΔN is not proportional. However, even if the PWM duty correction value maintaining time t _pwm is slightly changed, the actual engine speed change amount ΔN greatly changes. Therefore, it is not necessary to lengthen the control cycle as compared with the case where the PWM duty correction number n _pwm is changed. For this reason, when it is necessary to shorten the cycle of the PWM minute pulse control, it is preferable to perform the PWM minute pulse control by preferentially correcting the PWM duty correction value maintaining time t _pwm .

As described above, according to the present embodiment, the duty of the PWM signal given to the motor 160 that drives the throttle valve 170 is corrected by the PWM duty correction value Δduty over the PWM duty correction number n _pwm , and each time The correction of the PWM duty is continued for the PWM duty correction value maintaining time t _pwm . As a result, an accuracy of about 0.02 degrees is achieved as an angular accuracy by a feedforward control using a target engine speed change amount ΔN ^* or the like instead of a feedback control using an output of a throttle position sensor (TPS). , The opening of the throttle valve 170 can be finely controlled. This accuracy is equivalent to a configuration in which a bypass passage (sub-passage) is provided in parallel with the main intake passage of the engine, and the opening of the idle speed control valve (ISCV) disposed in the bypass passage is adjusted by the engine control unit. It is. Thus, the actual engine speed can be brought close to the target engine speed while controlling the throttle opening with the same accuracy as the control using the ISCV.

Moreover, the ISCV is not always necessary, and an amplifier that amplifies the output signal of the throttle position sensor is not necessary. Therefore, it is possible to control the engine speed, particularly the idle speed that requires fine control, with a simple and inexpensive structure.
Also, the initial values of the PWM control parameters of the PWM duty correction frequency n _pwm , the PWM duty correction value Δduty, and the PWM duty correction value maintaining time t _pwm (initial function values of the functions h1, h2, and h3. In particular, the coefficients h ₁ b, h ₂ b and h ₃ b) are set so that the minimum necessary torque exceeding the static friction force that prevents the displacement of the throttle valve 170 is generated from the motor 160. For this reason, even if the PWM duty is corrected using the initial function values of these PWM control parameters as they are, the actual engine speed can be brought close to the target engine speed almost as intended. In particular, even during idle speed control, the throttle valve 170 can be reliably opened and closed from a stationary state to a target opening position.

Further, the PWM minute pulse control table updating unit 250 uses the actual engine speeds N and N _old before and after the PWM minute pulse control every time the PWM minute pulse control is executed (for each control cycle). A change amount ΔN (= N−N _old ) is calculated. Further, the PWM minute pulse control table updating unit 250 uses the actual engine speed change amount ΔN and the target engine speed change amount ΔN ^* (and, if necessary, the actual engine speed N) as a PWM control parameter. Update the function that defines That is, at least one of the function h1 for determining the PWM duty correction number n _pwm , the function h2 for determining the PWM duty correction value Δduty, and the function h3 for determining the PWM duty correction value maintaining time t _pwm is changed as necessary.

  Therefore, in the PWM minute pulse calculation unit 240, when the throttle valve 170 does not open / close at the target opening degree by the PWM duty corrected by each PWM control parameter, the function of any PWM control parameter is changed. Thus, in the next processing (next control cycle), the throttle valve 170 can be surely made to perform a desired opening / closing operation.

  In this embodiment, the torque applied to the throttle valve 170 driven by the motor 160 is not constant due to the effects of the friction f1 of the shaft of the throttle valve 170, the gear backlash gb of the transmission mechanism of the throttle valve 170, the return spring, and the like. . Therefore, in the engine speed control device according to the present embodiment, the actual engine speed change amount ΔN is fed back, and the PWM minute pulse control table update unit 250 corrects the function h2 of the PWM duty correction value Δduty to ensure The throttle valve 170 is finely moved (see FIG. 8).

Further, in the process shown in FIG. 16, the PWM minute pulse control table updating unit 250 updates the function h2 of the PWM duty correction value Δduty when there is no change in the actual engine speed change amount ΔN. Thereby, the throttle valve 170 can be driven reliably and the engine speed can be controlled.
In the process shown in FIG. 16, the PWM minute pulse control table updating unit 250 shows that the actual engine speed change amount | ΔN | is the target engine speed although the actual engine speed N is changed by correcting the PWM duty. If the change amount is much smaller than | ΔN ^* |, the function h1 of the PWM duty correction number n _pwm or the function h3 of the PWM duty correction value maintaining time t _pwm is changed. As a result, it is possible to efficiently and reliably control the engine speed with high accuracy while maintaining the state in which the throttle valve 170 is finely moved by correcting the PWM duty.

(Second Embodiment)
FIG. 17 is a block diagram showing a configuration of an engine system according to the second embodiment of the present invention. The engine system includes an engine 120 and an engine speed control device 100a that controls the speed of the engine 120. The engine speed control device 100a has the same basic configuration as the engine speed control device 100 of the first embodiment shown in FIG. The description is omitted.

A throttle position sensor (hereinafter referred to as “TPS”) 310 is attached to the throttle valve 170. The TPS 310 is composed of a potentiometer or the like, detects the opening degree of the throttle valve 170, and outputs a signal (hereinafter referred to as “TPS signal”) to the actual throttle opening degree calculation unit 320.
The actual throttle opening calculation unit 320 calculates the actual throttle opening θ based on the TPS signal input from the TPS 310, the PWM minute pulse control table update unit (update unit) 250 a, the PWM minute pulse calculation unit (first control). (Signal calculation unit) 240a, PWM duty selection unit 390, ISC position feedback control unit (second control signal calculation unit) 330, and normal position feedback control unit 340.

The ISC position feedback control unit 330 includes a target throttle opening θ ^* (= θ + Δθ ^* ) (Δθ ^* is a target throttle opening change amount) input from the target throttle opening calculation unit 325, and an actual throttle opening calculation unit 320. From the actual throttle opening θ input from, a PWM duty that is a control signal for PWM control of the motor 160 is calculated and output to the PWM duty selector 390.

The normal position feedback control unit 340 determines the motor 160 based on the target throttle opening θ ^* input from the target throttle opening calculation unit 380 and the actual throttle opening θ input from the actual throttle opening calculation unit 320. A PWM duty, which is a control signal for PWM control, is calculated and output to the PWM duty selector 390.
An accelerator position sensor (APS) 360 is provided in the vicinity of an accelerator 350 for controlling the output of the engine 120 (for example, an accelerator pedal of a four-wheel vehicle, an accelerator grip of a two-wheel vehicle, or an accelerator lever of an engine generator) 350. Is provided. The APS 360 detects the opening (operation amount) of the accelerator 350 and outputs a signal (hereinafter referred to as “APS signal”) to the accelerator opening calculation unit 370.

The accelerator opening calculation unit 370 calculates the accelerator opening based on the APS signal input from the APS 360 and outputs the accelerator opening to the target throttle opening calculation unit 380.
The target throttle opening calculation unit 380 is an accelerator following target throttle opening calculation unit that generates the target throttle opening θ ^* based on the accelerator opening signal input from the accelerator opening calculation unit 370. The target throttle opening degree calculation unit 380 outputs the generated target throttle opening degree θ ^* to the normal position feedback control unit 340.

The target engine speed change amount calculation unit 220a calculates a difference (engine speed deviation) between the target engine speed N ^* and the actual engine speed N from the target engine speed N ^* and the actual engine speed N. In this embodiment, the engine speed deviation is directly used as the target engine speed change amount ΔN ^*. However, the target engine speed change amount ΔN ^* may be determined by performing a predetermined calculation.

Further, the target engine speed change amount calculation unit 220a adds the calculated target engine speed change amount ΔN ^* to the PWM minute pulse calculation unit 240a and the PWM minute pulse control table update unit 250a to calculate the target throttle opening change amount. Also output to the unit 400.
The target throttle opening change amount calculation unit 400 has a table that defines target throttle opening change amounts Δθ ^* corresponding to various values of the target engine speed change amount ΔN ^* . The target throttle opening change amount calculation unit 400 calculates the target throttle opening change amount Δθ ^* based on the table and the target engine speed change amount ΔN ^* input from the target engine speed change amount calculation unit 220a. calculate.

The target throttle opening change amount calculation unit 400 outputs the calculated target throttle opening change amount Δθ ^* to the PWM duty selection unit 390 and the target throttle opening calculation unit 325.
The target throttle opening calculation unit 325 calculates the target throttle opening θ ^* (= θ + Δθ ^* ) based on the input actual throttle opening θ and the target throttle opening change amount Δθ ^*, and ISC position feedback control. To the unit 330.

From the target engine speed change amount ΔN ^* calculated by the target engine speed change calculator 220a and the actual engine speed N calculated by the actual engine speed calculator 210, the PWM minute pulse calculator 240a Each PWM control parameter (PWM duty correction frequency n _pwm , PWM duty correction value Δduty, PWM duty correction value maintaining time t _pwm ) for PWM minute pulse control is calculated. The PWM duty based on these PWM control parameters is output from the PWM minute pulse calculator 240a to the PWM signal generator 280.

Further, the PWM minute pulse calculation unit 240a has the same function as the above-described PWM minute pulse calculation unit 240, and is input with the actual throttle opening degree θ.
Thereby, each PWM control parameter can be changed according to the actual opening degree θ of the throttle valve 170 that is driven and controlled by the PWM minute pulse control. That is, the PWM control parameter can be determined by a function of the target engine speed change amount ΔN ^* , the actual engine speed N, and the actual throttle opening θ.

Of course, as in the case of the first embodiment described above, the PWM control parameter is determined by a function of the target engine speed change amount ΔN ^* and the actual engine speed N, without considering the actual throttle opening θ. There is no problem. In this case, it is not necessary to input the actual throttle opening θ to the PWM minute pulse calculator 240a.
Actually, the throttle valve 170 does not have a constant static friction torque in all opening ranges. Therefore, if the PWM control parameter is determined in consideration of the actual throttle opening θ, the throttle valve 170 can be opened and closed more appropriately.

The PWM minute pulse control table updating unit 250a has the same function as the above-described PWM minute pulse control table updating unit 250, and is input with an actual throttle opening θ. As a result, the actual opening degree of the throttle valve 170 can be taken into account when determining the function update data to be output to the PWM minute pulse calculator 240a.
The PWM duty selection unit 390 receives signals from the PWM minute pulse calculation unit 240a, the ISC position feedback control unit 330, and the normal position feedback control unit 340 based on the actual throttle opening θ and the target throttle opening change amount Δθ ^* . One of them is selected and output to the PWM signal generation unit 280.

  FIG. 18 is a flowchart for explaining the processing of the PWM duty selection unit 390. When the actual throttle opening θ exceeds a predetermined threshold value θa (> 0) (YES in Step S21), the PWM duty selection unit 390 determines that the accelerator 350 is operated, and the normal time A control signal (a signal representing PWM duty) from the position feedback control unit 340 is selected and output (step S22).

If the actual throttle opening θ is equal to or smaller than the threshold θa (NO in step S21), the PWM duty selection unit 390 indicates that the absolute value | Δθ ^* | of the target throttle opening change amount is the first selection determination value θb1 (> 0) is determined (step S23). If this determination is affirmed, the PWM duty selection unit 390 selects and outputs a control signal from the normal position feedback control unit 340.

If the determination in step S23 is negative, that is, if | Δθ ^* | ≦ θb1, the PWM duty selector 390 further selects the target throttle opening change amount absolute value | Δθ ^* | It is determined whether or not the determination value θb2 (where θb1>θb2> 0) is exceeded (step S24). If this determination is affirmed, the PWM duty selection unit 390 selects and outputs a control signal from the ISC position feedback control unit 330 (step S25).

On the other hand, if the determination in step S24 is negative, that is, if | Δθ ^* | ≦ θb2, the PWM duty selection unit 390 selects and outputs the control signal from the PWM minute pulse calculation unit 240. (Step S26).
In this embodiment, the second determination value θb2 is set equal to the input resolution of the TPS signal. Therefore, in the case of | Δθ ^* | ≦ θb1, ISC position feedback control is performed if the absolute value | Δθ ^* | of the target throttle opening change amount is larger than the input resolution of the TPS signal. PWM minute pulse control is performed.

In this way, the PWM duty selection unit 390 performs the ISC position feedback control with a quick response, the PWM minute pulse control capable of finely controlling the engine speed, and the normal position feedback control according to the situation. Can be used by switching.
An example at the time of performing engine speed control using this engine speed control apparatus 100a is shown below.

FIG. 19 is an example of a time chart when the PWM minute pulse control and the ISC position feedback control are used in combination. FIG. 19A shows the behavior of the actual engine speed N and the target engine speed N ^* when switching between ISC position feedback control and PWM minute pulse control. FIG. 19B shows the behavior of the actual throttle opening θ and the target throttle opening θ ^* in that case. Further, FIG. 19C shows the fluctuation of the PWM duty in that case.

When the target engine speed fluctuates stepwise, the target throttle opening fluctuates substantially stepwise following this, so the absolute value | Δθ ^* | of the target throttle opening change amount increases. Therefore, in the control cycle in which the target throttle opening varies stepwise, ISC position feedback control is performed, and the PWM duty varies substantially linearly. On the other hand, during the period when the variation of the target throttle opening is small, the PWM minute pulse control is performed, and the PWM duty varies in a pulse shape.

FIG. 20 is an example of a time chart when switching between normal position feedback control and PWM minute pulse control. 20A shows the behavior of the actual engine speed N and the target engine speed N ^*, and FIG. 20B shows the behavior of the actual throttle opening θ and the target throttle opening θ ^* . FIG.20 (c) shows the fluctuation | variation of PWM duty.
When the actual throttle opening is large, normal position feedback control is performed, and the PWM duty varies greatly. On the other hand, when the actual throttle opening is small and the target throttle opening does not vary greatly, PWM minute pulse control is performed. During this period, the PWM duty fluctuates in a pulse manner.

  As described above, the PWM duty selection unit 390 appropriately selects the PWM duty generated by the PWM minute pulse calculation unit 240a, the ISC position feedback control unit 330, and the normal position feedback control unit 340 according to the situation, and generates a PWM signal. Part 280. Therefore, the engine speed can be appropriately controlled by different control depending on the situation.

  FIG. 21 is a diagram illustrating a configuration of a two-wheeled vehicle that is an example of a vehicle to which the engine system can be applied. The two-wheeled vehicle 1 includes a head pipe 2, a steering shaft rotatably supported by the head pipe 2, a handle 3 fixed to the upper end of the steering shaft, and a pair of gears connected to the lower side of the steering shaft. A front fork 5 is provided. A front wheel 6 is rotatably supported between the pair of front forks 5.

A frame 7 is connected to the head pipe 2. The frame 7 includes a pair of left and right main frames 7a each having a front end fixed to the head pipe 2, a rear frame 7b extending further rearward from the rear side of the main frame 7a, and a front side and a rear end portion of the main frame 7a. , And a down tube 7c joined in a downward curved state between them.
A front end portion of the swing arm 9 is rotatably supported on the main frame 7a. A rear wheel 10 is supported at the rear end of the swing arm 9.

An engine 120 is disposed between the main frame 7a and the down tube 7c. A fuel tank 8 for storing the fuel supplied to the engine 120 is disposed on the upper side of the main frame 7a.
The rotational force of the engine 120 is transmitted to the rear wheel 10 via the chain 11 or the like, and thereby the rear wheel 10 rotates. Thus, the two-wheeled vehicle 1 can be driven.

An accelerator grip (accelerator 350 in FIG. 19) for controlling the output of the engine 120 is disposed at the right-hand side end portion (back side in FIG. 21) of the handle 3, and an APS 360 (FIG. 17) is associated with this accelerator grip. Reference) will be placed.
The engine speed control device 100 or 100a is attached to, for example, the main frame 7a (not shown in FIG. 21). If the engine speed of the engine 120 is controlled by the engine speed control devices 100 and 100a, the engine speed can be precisely controlled, particularly during idling, and a stable speed can be obtained.

  FIG. 22 is a front view of an engine generator to which the engine system can be applied. The engine generator 21 is configured by disposing the engine 120 in the right half of FIG. 22 and the power generation unit 30 in the left half. A fuel tank 22 for storing fuel to be supplied to the engine 120 is disposed on the engine generator 21, and a carrying handle 23 is attached.

The frame 24 of the engine generator 21 is provided with an outlet 25 for taking out electric power from the power generation unit 30 and an engine switch 26. In this embodiment, the accelerator lever is not provided, the target engine speed is set according to the load connected to the outlet 25, and the engine speed is controlled.
The engine speed control device 100 or 100a for controlling the engine 120 is attached to, for example, a generator frame 24 (not shown in FIG. 22). By controlling the rotational speed of the engine 120 by the engine rotational speed control devices 100 and 100a, the engine rotational speed can be reliably controlled to a desired value with an inexpensive configuration. Thereby, stable electric power can be supplied.

  As mentioned above, although embodiment of this invention was described, this invention can also be implemented with another form. For example, in the above-described embodiment, the configuration not using the ISCV has been described. However, the present invention can also be applied to an engine system including the ISCV. FIG. 21 shows a two-wheel vehicle as an example of the vehicle, but the present invention can be applied to other types of vehicles such as a four-wheel vehicle and a three-wheel vehicle.

In the above-described embodiment, three types of PWM duty correction times n _pwm , PWM duty correction value Δduty, and PWM duty correction value maintenance time t _pwm are exemplified as PWM control parameters, and all of these can be changed. Explained. However, only one of these or only two of them may be changed, and the PWM minute pulse control may be performed.

  In addition, various modifications can be made within the scope described in the claims.

1 is a block diagram showing a configuration of an engine system according to a first embodiment of the present invention. It is a figure which shows the example of the function table for calculating a target engine speed. It is a figure for demonstrating the PWM control parameter used for PWM micro pulse control. It is a figure which shows the example of the function table for calculating a PWM control parameter. (A) is a schematic diagram which shows the structure of a throttle valve, (b) is a figure which shows the friction torque concerning a motor. It is a figure which shows the behavior of PWM duty, motor current, throttle opening, and engine speed. It is a flowchart explaining an engine speed control process. It is a flowchart which shows the update process of a PWM micro pulse control parameter function. It is a figure which shows the process timing of an engine speed control apparatus, (a) shows the time change of cooling water temperature, (b) shows the time change of target engine speed. It is a figure which shows the process timing of an engine speed control apparatus, (a) shows transition of an engine speed, (b) shows transition of PWM duty. It is a figure which expands and shows the relationship between the target engine speed and the real engine speed in the control period PC of FIG. It is a figure which shows the process timing of an engine speed control apparatus, (a) shows transition of an engine speed, (b) shows transition of PWM duty. It is a figure which expands and shows the relationship between the target engine speed and the actual engine speed in control cycle PC1 of FIG. It is a figure which shows the process timing of an engine speed control apparatus, (a) shows transition of an engine speed, (b) shows transition of PWM duty. It is a figure which expands and shows the relationship between the target engine speed and the actual engine speed in control cycle PC2 of FIG. It is a flowchart which shows the other example of a parameter function update process. It is a block diagram which shows the structure of the engine system which concerns on the 2nd Embodiment of this invention. It is a flowchart for demonstrating the process of a PWM duty selection part. It is a time chart which shows the engine speed control process of the said 2nd Embodiment, (a) is the actual engine speed and target engine speed at the time of switching and performing ISC position feedback control and PWM micro pulse control. (B) shows the behavior of the actual throttle opening and the target throttle opening in that case, and (c) shows the fluctuation of the PWM duty in that case. It is an example of a time chart when switching between normal position feedback control and PWM minute pulse control, (a) shows the behavior of the actual engine speed and the target engine speed, (b), The behavior of the actual throttle opening and the target throttle opening is shown, and (c) shows the fluctuation of the PWM duty. It is a figure which shows the structure of the two-wheeled vehicle which is an example of the vehicle which can apply the said engine system. It is a front view of an engine generator to which the engine system can be applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Two-wheel vehicle 2 Head pipe 3 Handle 5 Front fork 6 Front wheel 7 Frame 7a Main frame 7b Rear frame 7c Down tube 8 Fuel tank 9 Swing arm 10 Rear wheel 11 Chain 21 Engine generator 22 Fuel tank 23 Handle 24 Frame 25 Outlet 26 Engine Switch 30 Power generation unit h1 to h3 Function table Δduty PWM duty correction value n _pwm Duty correction frequency t _pwm Duty correction value maintenance time 100 Engine speed controller 100a Engine speed controller 110 Crank angle sensor 120 Engine 130 Water temperature sensor 140 Water temperature calculation Part 160 Motor 161 Throttle body 161a Intake passage 162 Transmission mechanism 163 Shaft part 170 Throttle valve 180 Control part 200a Target rotation Number setting section 200b Pulse generation section 210 Actual engine speed calculation section 220 Target engine speed change amount calculation section 220a Target engine speed change amount calculation section 240 PWM minute pulse calculation section 240a PWM minute pulse calculation section 250 PWM minute pulse control table Update unit 250m Storage unit 250a PWM minute pulse control table update unit 260 Target engine speed calculation unit 260m Storage unit 280 PWM signal generation unit 280m Storage unit 320 Actual throttle opening calculation unit 325 Target throttle opening calculation unit 330 ISC position feedback control Unit 340 normal position feedback control unit 350 accelerator 370 accelerator opening calculation unit 380 target throttle opening calculation unit 390 duty selection unit 400 target throttle opening change amount calculation unit

Claims (20)

A throttle valve for adjusting the amount of intake air taken into the engine;
A drive unit for driving the throttle valve;
A control unit that generates a PWM signal for driving the driving unit,
The controller is
An actual engine speed detector for detecting the actual engine speed;
A target speed setting unit for setting the target engine speed;
A target engine speed change amount for calculating a target engine speed change amount using the actual engine speed detected by the actual engine speed detection unit and the target engine speed set by the target engine speed setting unit. A calculation unit;
The PWM duty correction value for correcting the duty ratio of the PWM signal, the PWM duty correction value maintenance time to which the PWM duty correction value should be applied continuously, and the number of PWM duty corrections to which the PWM duty correction value should be applied A PWM control parameter including at least one of them is calculated according to the target engine speed change amount calculated by the target speed change amount calculation unit, and a PWM signal is calculated based on the calculated PWM control parameter. An engine speed control device comprising: a PWM pulse generation unit that generates and sends the generated pulse to the drive unit. In the PWM pulse generator, an initial value of the PWM control parameter is set,
2. The initial value is set so that a minimum necessary driving force exceeding a static frictional force that prevents displacement of the throttle valve is applied to the throttle valve from the driving unit. Engine speed control device.   3. The engine speed control device according to claim 1, wherein the PWM pulse generation unit calculates the PWM control parameter by a function of the target engine speed change amount.   The PWM pulse generation unit determines the PWM control parameter as a function of the target engine speed change amount calculated by the target speed change amount calculation unit and the actual engine speed detected by the actual speed detection unit. 3. The engine speed control device according to claim 1, wherein the engine speed control device calculates the engine speed. The PWM pulse generation unit calculates the PWM control parameter according to the target engine speed change amount calculated by the target speed change amount calculation unit, and based on the calculated PWM control parameter, drives the drive unit. A first control signal calculation unit that calculates a first control signal for PWM control, and a signal generation unit that generates the PWM signal to be sent to the drive unit,
The engine speed control device further includes a throttle opening degree detection unit that detects a throttle opening degree that is an opening degree of the throttle valve;
A target throttle opening change amount calculating unit that calculates a target throttle opening change amount from the target engine speed change amount calculated by the target engine speed change calculating unit;
A target throttle opening calculator that calculates the target throttle opening using the target throttle opening change amount and the actual throttle opening detected by the throttle opening detector;
A second control signal for PWM control of the drive unit is calculated to bring the actual throttle opening detected by the throttle opening detection unit closer to the target throttle opening calculated by the target throttle opening calculation unit. A second control signal calculation unit;
Based on the target throttle opening change amount calculated by the target throttle opening change amount calculation unit, one of the first control signal and the second control signal is selected and output to the signal generation unit And a selection unit to
5. The engine speed control device according to claim 1, wherein the signal generation unit is configured to generate the PWM signal based on a control signal supplied from the selection unit.   The selection unit, when the target throttle opening change amount calculated by the target throttle opening change amount calculation unit is less than or equal to a predetermined selection determination value based on the input resolution of the throttle opening detection unit, When the first control signal is selected and output to the signal generation unit, and the target throttle opening change amount calculated by the target throttle opening change amount calculation unit is larger than the selection determination value, the second control is performed. 6. The engine speed control device according to claim 5, wherein a signal is selected and output to the signal generator. An accelerator follow-up target throttle opening calculation unit for calculating a target throttle opening based on the accelerator opening;
A third control signal for PWM controlling the drive unit to bring the actual throttle opening detected by the throttle opening detection unit closer to the target throttle opening calculated by the accelerator follow target throttle opening calculation unit; A third control signal calculation unit for calculating,
The selection unit is configured to control the first control signal based on an actual throttle opening detected by the throttle opening detection unit and a target throttle opening change calculated by the target throttle opening change calculating unit. The engine speed control device according to claim 5 or 6, wherein one of the second control signal and the third control signal is selected and output to the signal generator.   The selection unit selects and outputs the third control signal when the actual throttle opening detected by the throttle opening detection unit exceeds a predetermined threshold, and the actual throttle opening Is less than or equal to the threshold value, any one of the first control signal, the second control signal, and the third control signal is selected according to the target throttle opening change amount calculated by the target throttle opening change amount calculation unit. 8. The engine speed control device according to claim 7, wherein the engine speed is selected and output. The PWM pulse generation unit repeatedly executes PWM correction control for sending a PWM signal corresponding to the PWM control parameter to the drive unit at intervals.
The engine speed control device includes:
Using the actual engine speed detected by the actual speed detector before a certain PWM correction control and the actual engine speed detected by the actual speed detector after the PWM correction control, An actual engine speed change amount calculating section for calculating an engine speed change amount;
The target engine speed change amount calculated by the target engine speed change amount calculated by the target engine speed change amount calculation unit and the actual engine speed change amount calculated by the actual engine speed change amount calculation unit. 9. The engine speed control device according to claim 1, further comprising: a changing unit that changes a relationship between the PWM control parameter for the PWM correction control after the next time and the PWM control parameter.   When the absolute value of the actual engine speed change amount calculated by the actual engine speed change amount calculation unit is substantially zero, the changing unit is configured to change the PWM duty correction value with respect to the target engine speed change amount. The engine speed control device according to claim 9, wherein the relationship is changed.   The changing unit has an absolute value of the actual engine speed change amount calculated by the actual engine speed change amount calculation unit that is not substantially zero, but is calculated by the target speed change amount calculation unit. When the difference from the absolute value of the target engine speed change amount exceeds a predetermined threshold value, the relationship between the PWM duty correction value maintaining time or the PWM duty correction frequency with respect to the target engine speed change amount is changed. The engine speed control device according to claim 9 or 10, characterized in that Engine,
An engine system comprising the engine speed control device according to any one of claims 1 to 11. An engine system according to claim 12;
A vehicle including a traveling wheel that is rotationally driven by a driving force generated by the engine. An engine system according to claim 12;
An engine generator comprising: a power generation unit that operates using the engine as a drive source. An engine speed control method for controlling the engine speed by driving a throttle valve by a drive unit driven by a PWM signal,
An actual engine speed detecting step for detecting an actual engine speed;
A target speed setting step for setting the target engine speed;
A target engine speed change amount calculating step for calculating a target engine speed change amount using the detected actual engine speed and the set target engine speed;
The PWM duty correction value for correcting the duty ratio of the PWM signal, the PWM duty correction value maintenance time to which the PWM duty correction value should be applied continuously, and the number of PWM duty corrections to which the PWM duty correction value should be applied A PWM control parameter calculating step of calculating a PWM control parameter including at least one of them according to the calculated target engine speed change amount;
A PWM signal sending step for generating a PWM signal based on the calculated PWM control parameter and sending it to the drive unit;
An engine speed control method comprising:   The method further includes the step of setting the initial value of the PWM control parameter such that a minimum necessary driving force exceeding a static frictional force that prevents displacement of the throttle valve is applied from the driving unit to the throttle valve. The engine speed control method according to claim 15.   17. The engine speed control method according to claim 15 or 16, wherein the PWM control parameter calculation step includes a step of determining a PWM control parameter based on the target engine speed change amount and the actual engine speed. . Generating a first control signal based on the calculated PWM control parameter;
A throttle opening degree detecting step for detecting an actual throttle opening degree that is an opening degree of the throttle valve by a throttle opening degree detecting unit;
A target throttle opening calculation step for calculating a target throttle opening using the target engine speed change amount and the detected actual throttle opening;
Calculating a second control signal for PWM control of the drive unit so as to bring the actual throttle opening closer to the target throttle opening;
The PWM signal sending step includes a control signal selection step for selecting one of the first control signal and the second control signal;
18. The engine speed control method according to claim 15, further comprising: generating a PWM signal based on the selected control signal and sending the PWM signal to the drive unit. The control signal selection step includes
Selecting the first control signal when a target throttle opening change amount corresponding to the target engine speed change amount is equal to or less than a predetermined selection determination value based on an input resolution of the throttle opening detection unit; ,
19. The engine speed control method according to claim 18, further comprising a step of selecting the second control signal when the target throttle opening change amount is larger than the selection determination value. The actual engine speed change for calculating the actual engine speed change amount using the detection result of the actual engine speed before and after the PWM correction control for sending the PWM signal corresponding to the PWM control parameter to the drive unit A quantity calculating step;
Using the target engine speed change amount and the actual engine speed change amount to further change the relationship between the target engine speed change amount and the PWM control parameter for PWM correction control from the next time onward. The engine speed control method according to any one of claims 15 to 19, further comprising:

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