JPH0320764B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a digital control method for controlling the rotational phase angle, etc. of a fuel injection pump of an automobile.

If the response speed of a hydraulic actuator used in a digital control system with a feedback loop is slow, hunting may occur even with simple on/off control where the application time of the instruction signal is constant. Never. However, when increasing the response speed,
Hunting phenomenon is likely to occur.

This is almost always true within the control system.
This is because there are components of response delay and hysteresis. Furthermore, in digital control, in addition to the response delay and hysteresis mentioned above, the rise of the instruction signal sent to the hydraulic actuator, regardless of the magnitude of the control deviation value. , or the fact that the gain change at the end is forced to be abrupt makes hunting more likely to occur.

To solve these problems, conventionally, the signal to the hydraulic actuator is a periodic pulse signal that vibrates in both directions, and the duty ratio of the two directions is controlled, so that the average position of the hydraulic actuator is controlled vibrationally. However, the control is essentially similar to analog control, thereby preventing the hydraulic actuator from moving on and off excessively and causing the control to hunt. (pulse width modulation)
There are control methods such as

However, in these control methods based on duty ratio control, the solenoid valve used in the hydraulic actuator is constantly used in vibration mode, so the number of on/off times of the solenoid valve is equivalent to the number of vibrations.
Repeated turning off deteriorates the durability of the solenoid valve, so it is not appropriate to employ such duty ratio control for controlling devices that require durability.

The purpose of the present invention is to solve the above problems.
It is an object of the present invention to provide a control method for digital control that improves the responsiveness and control accuracy of a control system without impairing durability.

To explain the present invention based on an embodiment, FIG. 1 shows a digital control method according to an embodiment of the present invention used to operate an injection timing adjustment device 2 of a fuel injection pump 4 in a diesel engine 1. This figure shows a system diagram when Crankshaft 1 of diesel engine 1
The gear 1c fitted to the input shaft 2a of the injection timing adjustment device 2 and the gear 2c fitted to the input shaft 2a of the injection timing adjustment device 2 form a gear connection, and the output shaft 2b of the injection timing adjustment device 2 drives the fuel injection pump 4. The injection timing adjustment device 2 changes the rotational phase angle between the input shaft 2a and the output shaft 2b according to the operating state of the diesel engine 1, thereby adjusting the injection timing in the fuel injection pump 4. It is to be set appropriately, and the injection timing adjustment device 2 uses a known device.

The hydraulic pump device 3 is driven via gears 2c and 3a, and the hydraulic pump device 3 is connected to a pipe 3b.
It serves as a constant oil pressure source for the solenoid valve 5F via the solenoid valve 5F.

A disc 1b for measuring rotational angle and rotation speed is fitted onto the crankshaft 1a, and a similar disc 4a is fitted onto the output shaft 2b, and the circumferences of each of the discs 1b and 4a are fitted. On the top, protrusions are arranged at equally divided positions in the circumferential direction, and the disc 1b
Electromagnetic pickups 5H and 5G for detecting the rotational position of the protrusion are fixedly installed at positions on the circumferences of the protrusions and 4a, respectively. Note that 5a and 5b are electric wires.

The electric wire 5c transmits the displacement of the accelerator pedal that operates the diesel engine 1, the electric wire 5d transmits the water temperature in the water jacket of the diesel engine 1, and the electric wire 5e transmits the atmospheric temperature to the input interface 5A. .

Input interface 5A, central processing circuit 5
B, memory 5E and output interface 5D
The electric wire 5k consists of one electric wire _5k1 in FIG. 3 and the other electric wire _5k2 not shown, and the output in the microcomputer 5 is electromagnetic through the electric wire 5m. It controls the valve 5F, and the solenoid valve 5
F is connected to the injection timing adjustment device 2 via the hydraulic pipe 5n.
It operates the hydraulic actuator inside.

As shown in FIG. 2, the input interface 5A is composed of a Schmitt circuit 5AB, an analog multiplexer 5AD and an A-D converter 5AE, and 5p, 5q, 5r, 5s and 5t are electric wires, respectively.

Figure 3 shows one output interface 5D ₁ in the circuit diagram of the output interface 5D, and one of the electric wires 5k, which is the output of the central processing circuit 5B, is connected to the resistor _R1 . ₁ is connected, and the electric wire 5u is connected to a constant voltage power supply,
The electric wire 5m ₁ is connected to one solenoid 5F ₁ of the electromagnetic valve 5F in FIG. 1, D is a flywheel diode, R ₂ and R ₃ are resistors, and TR ₁ and TR ₂ are transistors.

Note that the output interface of the other of the electric wires 5k, to which the other electric wire _5k2 is input, is omitted because it is the same as that in FIG. 3.

In the configuration shown in FIGS. 1, 2, and 3, the operation thereof will be explained. The diesel engine 1 is driven by the operation of an accelerator pedal (not shown), and the fuel injection pump 4 is driven by the crankshaft 1.
a, gears 1c and 2c, input shaft 2a, injection timing adjustment device 2 and output shaft 2b,
The injection timing adjustment device 2 is controlled by the rotation speed of the diesel engine 1, the displacement of the accelerator pedal, the water temperature of the water jacket (hereinafter simply referred to as water temperature), and the atmospheric condition. Hydraulic signal (control power) from 5n (multiple)
to operate the hydraulic actuator in the injection timing adjustment device 2 in one direction or the other,
As a result, the injection timing adjustment device 2 changes the relative rotational phase angle (hereinafter simply referred to as rotational phase angle) between the input shaft 2a (that is, also equivalent to the crankshaft 1a) and the output shaft 2b, and as a result, the fuel injection The injection timing of the pump 4 is set appropriately.

The injection timing is set by turning the solenoid valve 5F on or off to one side or the other according to the output instruction signal of the microcomputer 5, and the hydraulic signal from the solenoid valve 5F amplified by this operation indicates the injection timing. Although the adjustment device 2 is operated and set, the operation of the microcomputer 5 that controls the solenoid valve 5F will be explained below.

The displacement of the accelerator pedal, the water temperature, and the atmospheric temperature are detected in analog form by detectors (not shown), and as shown in FIG. 2, command signals are sent from the central processing circuit 5B via the electric wire 5r at any time. , the respective detection values are alternately selected in the analog multiplexer 5AD, and the alternately selected detection signals are A-
In the D converter 5AE, the analog values are converted into digital values and each is input to the central processing circuit 5B.

The respective rotation angles of the crankshaft 1a and the output shaft 2b are determined by the electromagnetic pickups 5H and 5.
G, and the respective detected signals are the signals 5as and 5bs shown in FIG.
The detection signal is input to the Schmitt circuit 5AB (FIG. 2).

Note that the horizontal axis in FIG. 6 indicates elapsed time.

Pulse signals sa and sb in FIG.
It shows the voltage change value that occurs when the voltage exceeds (passes).

Each of these pulse signals sa and sb is
In the Schmitt circuit 5AB (FIG. 2), the signals _pa1 and pb are converted into rectangular waveform pulse signals and input to the central processing circuit 5B.

As the rotational speed of the crankshaft 1a increases, the waveforms of the pulse signals sa and sb change as shown by sa', so the pulse signals pa ₁ and pb undergo waveform shaping with reference to the reference voltage level d.
changes as pa ₁ ′, but the pulse signals sa and
The positions of points a and b of zero voltage in sb are not affected much by the rotation speed, so the pulse signal
The reference points of pa ₁ and pb are set at elapsed times corresponding to points a and b.

t ₁ and t ₂ each indicate the measurement time between the pulse signals pa ₁ and pb and the pulse signals pa ₁ and pa ₂ , respectively, and due to their properties, the input shaft 2a and the output shaft 2b The rotational phase angle pe between and the rotational speed n of the crankshaft 1a are as follows.

pe = (c ₁ × t ₁ ) / t ₂ ... (1) n = c ₂ / t ₂ ... (2) However, c ₁ and c ₂ are constants determined by the number of protrusions on the discs 1b and 4a. be.

In the memory 5E in FIG. 1, various data necessary for calculation in the central processing circuit 5B are stored.

To explain an example of this stored data, the fuel injection timing of the diesel engine 1 is ideally set based on the water temperature, the atmospheric temperature, the displacement θ of the accelerator pedal, and the rotational speed n of the crankshaft 1a. In this case, the fuel consumption rate or exhaust gas composition of the diesel engine 1 can be optimized, and for this purpose, the memory 5 is
Among these relationships, for example, the target rotational phase angle peo to be set by the injection timing adjustment device 2 in the relationship between the displacement θ of the accelerator pedal and the rotational speed n of the crankshaft 1a is expressed as shown in FIG. It is stored in the map state.

In addition, each + mark in FIG. 5 is p ₃₃ , p ₃₄ ,
As shown in p ₄₃ and p ₄₄ , each target rotational phase angle corresponding to the relationship between the displacement θ of each accelerator pedal and the rotational speed n of the crankshaft 1a is stored at equal intervals, and these are Values that change according to changes in temperature are stored.

In addition, in FIG. 5, the electromagnetic pick-up 5H
Actual operating point p determined by the rotational speed n found from and the displacement θ of the accelerator pedal at that time.
The target rotational phase angle peo is determined by the target rotational phase angles p ₃₃ , p ₃₄ , p ₄₃ and p ₄₄ in the neighborhood e of point p, and the neighborhood e is shown in an enlarged view in FIG.

In FIG. 4, Ld and dL are the displacement differences of the accelerator pedal, nd and dn each indicate the rotation difference, and the target rotational phase angle peo at point p is calculated in the central processing circuit 5B using the following formula. ing.

peo={(A-B)dn/nd}+B ……(3) However, A={(p ₄₄ −p ₃₄ )dL/Ld}+p ₃₄ ……(4) B={(p ₄₃ −p ₃₃ ) dL/Ld}+p ₃₃ (5) Note that all of the above equations (1) to (5) are stored in the memory 5E.

The target rotational phase angle peo obtained from equation (3) above is compared with the actual rotational phase angle pe obtained from equation (1), and by the comparison, it is found that under normal conditions, By performing the following calculation steps using the characteristics shown in FIG. 7, an instruction signal is given to the electric wire 5k (FIG. 1).

That is, Step 1) Find peo−pe=Er.

Step 2) Store the absolute value of the deviation Er in memory 5E.
Compare with the respective absolute values of the minimum standard deviation Ero and the maximum standard deviation Er ₁ stored in .

Step 3) When the absolute value of the deviation Er is smaller than the absolute value of the minimum standard deviation Ero, the voltage value of the instruction signal is set to zero.

Step 4) The absolute value of the deviation Er is the minimum standard deviation
Greater than the absolute value of Ero and the maximum standard deviation
When the absolute value of Er ₁ is smaller than the absolute value of Er 1, the central processing circuit 5B determines the sign of the deviation Er, and when the deviation Er is positive, it gives this as one of the instruction signals to the electric wire 5k ₁ in FIG. When Er is negative, control is performed so that the deviation Er is minimized by applying this as the other instruction signal to the aforementioned electric wire _5k2 (not shown). At this time, the pulse application time of one of the above instruction signals or the other instruction signal has a deviation
The minimum application time tso in FIG. 7 is added to the application time proportional to Er, and the pulse width is shaped like a waveform.

Step 5) When the absolute value of the deviation Er is larger than the absolute value of the maximum standard deviation Er ₁ , the electric wire 5k ₁ or 5k ₂ is continues to output instruction signals.

The instruction signal characteristics resulting from the above calculations are as shown in FIG.

In addition, in Fig. 8, the upper pulse is connected to the electric wire 5k ₁ ,
The lower side is given to the wire 5k ₂ .

In FIG. 7, the vertical axis ts indicates the normal application time of the step-like instruction signal, and the horizontal axis Er
indicates the deviation, and the characteristic on the right side of the ts axis is the third
The characteristic on the left side of the ts axis indicates the application time of _{the instruction signal applied to the other electric wire 5k 2 (} not shown), and tso is the ts axis. The intersection points between the curve and the gradient of each solid line are shown.

What is important here is that in the above calculation step 4), the application time of the instruction signal output when the deviation Er occurs is the basic minimum application time tso plus the application time proportional to the deviation Er. At the point.

This means that when such a deviation occurs, in order to correct the deviation, the set value of the load is converged within the target tolerance by the first pulse instruction signal for the deviation. It means that it is aimed at.

In order to achieve such a purpose, we experimentally determined in advance, for each magnitude of deviation, the application time of the instruction signal that corresponds to the amount of time the instruction signal is applied to bring those deviations within the allowable range with one instruction signal. The length has been determined, and the application time determined experimentally corresponds to the application time in the calculation step 4).

Therefore, the correction control of the deviation by the calculation step 4) is designed to bring about a control within or near the allowable deviation by issuing only one instruction signal for the deviation. It is something.

In the normal case described above, the control described above is performed, but during the above action, for example, when the accelerator pedal is quickly released, the injection is controlled by the rotational inertia of the load. A state in which the torque in the timing adjustment device 2 is close to zero occurs, and when the hydraulic actuator manipulates the rotational phase angle at this time, the resistance of the load (torque in this case)
The relative control sensitivity for
In the vicinity of this time, in an attempt to correct the deviation Er, the normal application time ts of the relationship shown in FIG.
When control is performed, the deviation as a result of the control changes its sign to a different sign, resulting in a so-called overshoot phenomenon.

When an overshoot occurs in this way, a minute application time proportional to the amount of overshoot is stored in the memory 5E, and the next time an instruction signal to correct the deviation Er is sent in the same direction. ,
The instruction signal is an application time signal obtained by subtracting the memorized minute application time from the normal basic application time ts determined from FIG.

Thus, for the resistance of the controlled load,
When the control sensitivity is relatively high, the application time of subsequent instruction signals is shortened in proportion to the amount of overshoot, so the amount controlled by that one instruction signal is reduced. In particular, it is possible to attenuate the overshoot state and prevent the hunting phenomenon in the control system.

In addition, when the control sensitivity for load control as described above can become excessive, the following cases may occur where the control sensitivity decreases too much and this is automatically corrected, and the correction becomes overcorrection. .

That is, when the hydraulic oil in the hydraulic pump device 3 is in a considerably low temperature state in a cold region etc., the viscosity and specific weight of the hydraulic oil become high, so that the hydraulic oil flows from the conduit 3b to the solenoid valve 5F to the conduit 5n. Also, the responsiveness of the hydraulic control system leading to the injection timing adjustment device 2 (including the hydraulic actuator) has become slow.

In addition to this oil temperature drop, since the control system performs control with negative feedback, when the switch is turned on to start control, the load setting is The status is uncertain. As a result, the deviation Er between the target rotational phase angle peo and the actual rotational phase angle pe, which is the result of the above calculation, is often very large in its initial state. Therefore, in such an initial state, it is necessary to establish an appropriate control state as soon as possible, which becomes an important problem especially in the state where the oil temperature is low.

To explain this problem in the case of the embodiment of the present invention, when the engine of the automobile is warmed up after starting,
If the hydraulic oil temperature in the hydraulic control system decreases and the initial deviation Er of the load is large as described above, the optimization of the injection timing of the fuel injection pump 4 will be delayed, and the exhaust components from the engine will be This results in deterioration of fuel efficiency and fuel efficiency.

For this reason, in the embodiment of the present invention, if the responsiveness of the control system is decreased due to a decrease in the temperature of the hydraulic fluid in the hydraulic control system, the following control is performed. is being carried out.

Below, the control in this case will be explained in the 9th, 10th and 11th
This will be explained using figures.

That is, each vertical axis in FIGS. 9, 10, and 11 represents the deviation Er, the basic application time ts of the instruction signal obtained from FIG. The total application time dTs is shown, and each horizontal axis t shows the elapsed time, and the control in this case is to directly detect that the response of the gas system is slowing down. Instead, the calculation step 1) ~
5), and at the first deviation detection stage, if the deviation Er is at the value of point d ₁ in Fig. 9,
The central processing circuit 5B gives an instruction signal of the basic application time ts (corresponding to ₁ point e in FIG. 10) according to FIG. 7 to the electric wire 5k, but since the response of the system has slowed down, The deviation Er of the second detection result (corresponding to ₂ points d in Figure 9) is still the minimum standard deviation + Ero.
As a result, the central processing circuit 5B continues to send out the instruction signal for the basic application time ts (corresponding to ₂ points e in Figure 10) determined from the characteristics in Figure 7. , and d ₃ at the third deviation detection
Even at the point (Fig. 9), the deviation Er is +
If it does not become less than Ero, the first memory in memory 5E
The minute application time dts corresponding to the _f2 point (Fig. 11) is stored in the register of , and the stored minute application time dts is added to the basic application time ts determined according to Fig. 7. An instruction signal for the added application time is transmitted to the electric wire 5k, and at this time, dts at this time is set as dTs (corresponding to point g ₂ in Fig. 11),
Store this in the second register.

If the deviation Er still does not become smaller than +Ero even with the control using the above-mentioned added instruction signal, the value of the first register is replaced with the value corresponding to the _f3 point, and the value of the second register is replaced. A new dTs (g ₃
(equivalent to a point) is added to the basic application time ts, and an instruction signal of the added application time is sent to the electric wire 5k,
In addition, the second register is replaced with a value (corresponding to g ₃ ) to which this new first register value is added.

Similarly, when the deviation Er of the next detection result is not within the target +Ero to -Ero, such as at point _d5 , the value of the first register becomes _f4 , and this _f4 and the previous g ₃ (equivalent to g ₄ ) is added to the basic application time ts, and this is given to the electric wire 5k in Figure 1 as an instruction signal, and the second register is replaced with the value of g ₄ . .

However, at this time, as a result of the instruction signal sent to the electric wire 5k adding minute application times dts one after another,
The control amount by one instruction signal increases, that is, the control sensitivity increases, and in the next deviation detection, there is a possibility that an overshoot as shown in _d6 in FIG. 9 will occur.

In such a state, naturally, the instruction signal is transmitted from 5k ₁ to 5k ₂ of the electric wire 5k, or vice versa, and the deviation (d ₆ ) is converted to e ₆ in the opposite way to the above. The correction is made by transmitting an instruction signal opposite to the previous instruction signal determined from FIG. 7 corresponding to . As a result, the deviation is again on the opposite first side, and the next instruction signal that attempts to bring the deviation into the desired range (+Ero to -Ero) will be applied to _d6 , which caused the overshoot. The minute application time is proportional to the amount.
Subtract it from the previous dTs (g ₄ in Figure 11), store this subtracted new dTs (corresponding to g ₅ ) in the second register, and use this dTs as the next time determined from Figure 7. is added to the basic application time ts. Also,
This is based on ts with g ₄ added,
Thereafter, the application time proportional to the overshoot amount may be subtracted from the basic value.

In addition, if the overshoot continues,
A similar application time subtraction is performed.

In addition, in Fig. 11, the value of dts is the deviation Er
When the value falls within the desired range of +Ero to -Ero or is overshot, the value of the first register is set to zero, such as _f5 .

In this way, in the above control, the control system detects the deviation Er and corrects the deviation Er without directly detecting a drop in oil temperature in the hydraulic control system, a slowing in the response of the control system, or a sudden change in the load condition. The series of correction controlled times is
Even if the predetermined number of times is reached, the deviation Er remains at the desired value (+
If the deviation Er does not decrease within (Ero~-Ero) or the sign of the deviation Er does not change (overshoot), the normal application time ts is applied until the deviation Er reaches the desired value. Minute application time
A new application time instruction signal with dts added one after another is transmitted, and when an overshoot occurs due to the transmission control, the application time is corrected by an amount proportional to the overshoot. To summarize the method of adding this additional application time, the basic application time ts in the deviation detection time is
The application time dTs to be added to the deviation detection time is the sum of the dTs in the previous deviation detection time and the dts in that time.

Note that the above minute time dts is f ₂ , f ₃ and f ₄ (first
The relationship of increasing time as shown in Figure 1) is a value obtained by multiplying a certain constant value by the number of consecutive deviation detections.

Further, in the above description, a case has been described in which the load is controlled to one side, but the same effect occurs when the deviation is corrected from a negative value to within -Ero to +Ero.

As is clear from the above description, the effects of the present invention are as follows.

Unlike the conventional method of continuing to output the instruction signal until the deviation becomes zero, after the detection of the deviation Er is completed, based on the detected deviation value Er, A method is adopted in which an instruction signal is output for an application time ts that is sufficient to correct the value of the deviation Er to exactly zero, that is, an application time ts that is the minimum application time ts ₀ and an application time proportional to the deviation Er at that time. ing. Therefore, the deviation Er is corrected to a value of almost zero by only one pulse of the instruction signal in that control cycle.

Therefore, the response of the control becomes very quick, and the number of signal transmissions applied to the solenoid valve is reduced, so that the durability of the solenoid valve is improved.

In addition, in the control of the present invention, the sensitivity of the control system is in a special state, so the sensitivity becomes relatively high, and as a result, the sensitivity can be corrected by sending a one-pulse instruction signal as described above. is overcorrected, that is, if the correction result of the above deviation due to the application of that instruction signal overshoots, the application time of a new instruction signal transmitted in the same direction that overshot the next time is calculated from the application time of that new instruction signal. , the application time proportional to the overshoot amount (the application time proportional to the overcorrection amount) is subtracted. Therefore, since the control sensitivity of the control system has become excessive relative to the resistance of the controlled load, the amount of overshoot increases, and the greater the amount, the more the overshoot increases. As the shootability is rapidly reduced, the hunting phenomenon no longer occurs.

Furthermore, when the digital control method of the present invention is used in a fuel injection timing adjustment device for an engine, it is necessary to prevent the control system from hunting, which may disable the operation of the engine. Such countermeasures are particularly important when driving on expressways, etc., and it is important to ensure that the vehicle is driven safely and that the vehicle is properly controlled by the injection timing adjustment device. As a result, it is possible to achieve optimization of fuel consumption and exhaust gas.

[Brief explanation of the drawing]

FIG. 1 shows a system diagram when the digital control method of the present invention is used in a fuel injection timing adjustment device 2 of a diesel engine 1, and FIG. 2 shows an input interface 5 in FIG.
FIG. 3 shows a circuit diagram of one of the output interfaces 5D in FIG. 1, and FIG. ₄ shows a block diagram of FIG. FIG. 5 is an enlarged view of neighborhood e in FIG. 5, and shows a map digitally showing the target rotational phase angle of the fuel injection pump determined by the relationship between the accelerator pedal θ and the engine rotational speed n. FIG. 6 shows that the signals 5as and 5bs detected by the electromagnetic pickups 5G and 5H in FIG.
The respective signals 5as and 5bs are converted into rectangular waveform signals 5ap and 5bp in the Schmitt circuit 5AB of FIG. 2, respectively, and show their respective characteristics. FIG. 7 shows the characteristics of the relationship between the pulse application time ts and the deviation Er of the control signal output to the electric wire 5k shown in FIG. 1, and FIG.
According to the characteristics in the figure, the electric wire 5 in Figure 1
FIG. 9 shows the time-lapse characteristics of the deviation Er in a series of control operations, and FIG. 10 shows the application time characteristics of the instruction signal that changes according to FIG. 9. 11 shows minute application time characteristics dts that change according to FIG. 9,
It shows the characteristic dTs of the total value of the minute application time added to the instruction signal. The symbols used in the examples are as follows:
1: Diesel engine, 1a: Crankshaft, 1
b: disk, 1c: gear. 2: Injection timing adjustment device,
2a: input shaft, 2b: output shaft, 2c: gear. 3:
Hydraulic pump device, 3a: gear, 3b: piping. 4:
Fuel injection pump, 4a: disc. 5: Microcomputer, 5A: Input interface, 5
AB: Schmitt circuit, 5AD: Analog multiplexer, 5AE: A-D converter, 5B:
Central processing circuit, 5D: Output interface, 5
D ₁ : One output interface, 5E: Memory, 5F: Solenoid valve, 5F ₁ : One solenoid,
5G and 5H: Electromagnetic pick-up. 5a, 5
b, 5c, 5d, 5e, 5f, 5g, 5h, 5
j, 5k, 5k ₁ , 5m, 5m ₁ , 5p, 5q, 5
r, 5s, 5t and 5u: electric wire, 5n: piping,
5as, 5bs, 5ap and 5bp: signal. sa, sa′,
sb, pa ₁ , pa ₁ ′, pa ₂ and pb: pulse signal, t ₁ and t ₂ : measurement time, θ: accelerator pedal displacement,
n: rotation speed of diesel engine 1, p ₃₃ ,
p ₃₄ , p ₄₃ and p ₄₄ : target rotation phase angle in injection timing adjustment device 2, Ld and dL: displacement difference, dn and nd: rotation difference, p: actual operating point, d: reference voltage,
a, b and c: points, R ₁ , R ₂ and R ₃ : resistors,
TR ₁ and TR ₂ : Transistor, D: Diode, ts: Application time of the square wave voltage (instruction signal) applied to the wire 5k, dTs: Total minute application time added to ts, dts: Minute amount added to dTs Application time, Er: Deviation between the target rotational phase angle and the actual rotational phase angle for the injection timing adjustment device 2, Ero: Minimum standard deviation, Er ₁ : Maximum standard deviation, tso: Virtual minimum application time.

Claims (1)

[Scope of Claims] 1. The application of a single on-state instruction signal manipulates the load in the direction of the application during the application, and the application of the instruction signal comprises: a; Calculate the deviation value between the detected value of the set value set at the load and the target set value that should be set for that load, b; The absolute value of the deviation value and the absolute value of the minimum standard deviation value. c; when the absolute value of the deviation value is smaller than the absolute value of the minimum standard deviation value, the value of the instruction signal is set to zero; d; the absolute value of the deviation value is smaller than the absolute value of the minimum standard deviation value; When the absolute value of the reference deviation value is greater than the absolute value, the instruction signal is sorted into one instruction signal or the other instruction signal by determining the sign of the deviation value, e; The application time of
The relationship is such that the application time is the sum of the minimum application time and the application time proportional to the absolute value of the deviation value, and if the deviation correction result due to the application of the instruction signal overshoots, the next time A digital control system characterized in that the application time of a new instruction signal transmitted in the same direction that has been overshot is the application time of the new instruction signal minus the application time proportional to the overshoot amount. Control method.