JPS6187937A - Engine speed controller for internal-combusion engine - Google Patents

Abstract

PURPOSE:To reduce a variation in engine speed with periodicity, by calculating a basic operated variable from the detected engine speed and the desired engine speed, while making a controller compensate the basic operated variable by a minute operated variable to be produced at the specified period. CONSTITUTION:Each output signal out of an engine speed detecting device 1, detecting an engine speed, and a desired engine speed setting device 2, setting a desired engine speed, is inputted into a basic operated variable operational device 3, and operation takes place on the basis of both output signals, making it output a signal commensurate to a basic operated variable. And, with a minute disturbance generating device 4, a signal in response to a minute operated variable is generated at a fixed period or a random period, and in accordance with output of this device 4, a basic operated variable signal is compensated at an operating signal outputting device 5, making it output a final operation signal. And, with this operation signal, an engine speed controlling actuator 7 is controlled via a drive signal outputting device 6, thus the engine speed is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotation speed control device for an internal combustion engine, and more particularly to a rotation speed control device for an internal combustion engine using an electronic control method.

[Conventional technology]

Conventionally, a rotational speed control device for an internal combustion engine calculates a manipulated variable X = f (N, No) from the current rotational speed N detected by the engine's rotational speed detection means and a target rotational speed ratio, and calculates the manipulated variable X
The engine speed was controlled by driving an actuator that increased or decreased the amount of fuel supplied to the engine.

[Problem that the invention seeks to solve]

However, in such a rotation speed control device for an internal combustion engine, certain specific errors may occur due to causes such as subtle deviations in the control gain used to calculate the manipulated variable X, or variations between cylinders in an internal combustion engine that has multiple cylinders. Periodic rotational speed fluctuations may appear under operating conditions. This periodic fluctuation in the rotational speed is felt by people, even if the fluctuation is as small as 1Qrpm, and often gives a feeling of discomfort.

In order to suppress this rotational speed fluctuation, a passive method has conventionally been taken in which the control gain is delicately adjusted to avoid periodic rotational speed fluctuations. However, this method has a practical drawback in that the control gain must be investigated based on individual differences between products of internal combustion engines or actuators and changes over time. Furthermore, if the problem is caused by variations between the cylinders of the internal combustion engine, the problem cannot be solved by adjusting the control gain alone, and the problem must be resorted to, such as increasing the size of the flywheel.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a rotational speed control device for an internal combustion engine in which periodic rotational speed fluctuations are sufficiently small.

[Means for solving problems]

The present invention includes basic operation amount calculation means for calculating a basic operation amount from the current engine rotation speed detected by the rotation speed detection means and the target rotation speed which is a signal from the target rotation speed setting means, and A minute disturbance generation means that generates a minute amount of operation in a periodic manner, an operation signal output means that corrects the basic operation amount based on the minute amount of operation, and a drive signal that outputs an actuator drive signal based on the output signal of the operation signal output means. A rotation speed control device for an internal combustion engine, comprising an output means and a rotation speed control actuator that is driven by the output signal of the drive signal output means and adjusts the rotation speed.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the basic configuration of the device of the present invention is a rotation speed detection means 1 that outputs a signal according to the rotation speed of the internal combustion engine, and a target rotation speed setting that outputs a signal according to a predetermined target rotation speed. means 2; basic operation amount calculation means 3 that performs calculations based on at least the output signal of the rotation speed detection means 1 and the output signal of the target rotation speed setting means 2 and outputs a signal corresponding to the basic operation amount; The output signal of the basic operation amount calculation means 3 is corrected by the output signal of the minute disturbance generation means 4 which generates a signal corresponding to the minute operation amount at a fixed period or a random period, and the minute disturbance generation means 5, and the final signal is generated. An operation signal output means 5 that outputs an operation signal, a drive signal output means 6 that outputs an actuator drive signal based on the output signal of the operation signal output means 5, and an actuator driven and rotated by the output signal from the drive signal output means 6. 2. Next, FIG. 2 shows an embodiment in which the basic structure of the present invention is applied to a diesel engine. In FIG. 2, 8 is a diesel engine, 9 is a fuel injection nozzle, 10 is a distribution type fuel injection pump, and 11 is a linear actuator 7 for controlling the rotation speed, which increases or decreases the amount of fuel supplied according to the operation amount from the control unit 12. - Actuator 12 is a control unit that combines basic operation amount calculation means 3, target rotation speed setting means 2, minute disturbance generation means 4, and operation amount output means 5,
13 is a transistor circuit as drive signal output means 6;
14 is a rotation speed detector as rotation speed detection means 1 that detects the rotation speed of the crankshaft by an electromagnetic pickup; 15 is a volume for target rotation speed setting means attached to the accelerator pedal; and 16 is a starter switch turned on. This is the starter switch signal that becomes 1L" logic when it becomes 1L.

In the embodiment, when a pulse signal with a varying duty ratio as shown in FIG. 4(a) is applied to the linear actuator 11, the repulsive force between the coil and the permanent magnet in the linear actuator 11 changes, and this The spill ring moves to a point where the repulsive force and the spring force within the distribution fuel injection pump are balanced, and the amount of fuel supplied to the injection nozzle 9 is increased or decreased.

The control unit 12 also includes an input/output interface 51,
It is composed of a CPU 52 and a memory 53,
The memory 53 stores programs, control gain constants necessary for calculating basic manipulated variables, constants necessary when a slight disturbance occurs, and the like. Further, the CPU 52 determines whether the diesel engine 8 is in a stop mode, a starting mode, or an operating mode depending on the operating state, and if it is in the operating mode, the CPU 52 reads signals from the rotational speed detection means and target rotational speed setting means and from the memory 53. The basic operation amount is calculated based on the control gain constant, and it is further determined whether or not it is the minute disturbance generation timing.17 If it is the occurrence timing, the memory 5 is
After reading out the constants necessary for the generation of a minute disturbance from 3, calculations are performed to find the amount of minute disturbance. Then, by adding this minute operation amount and the above-mentioned basic operation amount to obtain the final operation amount, and giving this operation amount to the linear actuator 11 via the interface 51 and the transistor circuit 6, the diesel engine 8 is rotated. Perform numerical control.

Further, the operation will be explained in detail using FIG.

Here, FIG. 3 shows a flowchart of the rotation speed control of the CPU 52.

When the control unit 12 is powered on, the CPU 52 first initializes the registers, memory 53, etc. in the CPU (
After performing step 101), each sensor 14 to 16
The output signal of is read through the interface 51 (
Step 102), based on the read long sword information, determine whether the control mode is stop mode, start mode, operation mode, or abnormal mode (step 104).
, 106, 107). Here, if the process is stopped, no particular processing is performed and the process returns to step 102. If it is the start mode, the constant operation amount stored in the memory 53 is read out and set as the final operation amount, and then step 112
Proceed to. If it is in the operation mode, the basic operation amount is calculated based on the signals from the rotation speed detection means and the target rotation speed setting means and the control gain constant read from the memory 53 (step 107). To determine whether the timing is right, the current rotation ti&N(K
) and the previously measured rotation speed N(K-1): the difference △N(K)-
N(K)-N(K-1) and the previously measured rotation speed N(K-1
) and the rotation speed N (K-2) measured before the previous time △N (K-
1) Find = N (K-1) - N (K-2) and drown (K)
is a positive number and ΔN(K-1) is a negative number (step 108), the value obtained by subtracting the minute operation amount from the basic operation amount is set as the final operation amount (step 110), and If is a negative number and W(K-1) is a positive number (step 109), the value obtained by adding the basic operation amount and the minute operation amount is set as the final operation amount (step 111), and the other If the condition is met, the basic operation amount is used as the final operation amount in step 11.
Proceed to step 2. Further, if none of the above-mentioned stop, start, and operation modes apply, it is determined that the mode is abnormal and all processes (step 113) are stopped.

In step 112, a pulse signal having a duty ratio corresponding to the final operation amount determined above is outputted to the linear actuator side via the interface 51, and then the process returns to step 102.

The linear actuator 11 calculated as above
An example of the pulse signal output during the operation mode is shown in FIG. 4(b). As shown in Fig. 4 (a), when the rotation speed is controlled only by the basic operation amount, the minute operation amount as shown in Fig. 4 (b) under operating conditions where periodic rotation speed fluctuations occur. When △X is added, the amount and speed of change in the rotation speed differs from what was originally intended by the control calculation side, and in order to stabilize the change, the control side must be placed under different operating conditions than before. Become. Since this slight disturbance is frequently applied, the rotational speed fluctuation does not lose its periodicity and becomes a random rotational speed fluctuation. Periodic fluctuations in rotational speed cause unpleasant sensations such as humming or hunting, while random fluctuations in rotational speed are difficult for humans to experience, so by using this device, people can feel as if the fluctuations in rotational speed are reduced. It feels as if the rotation is stable.

For this reason, the minute operation amount may be given in either a synchronous or asynchronous manner with respect to a fixed period, a random period, or the number of rotations.

Further, although this embodiment has been described with respect to a diesel engine, the device according to the present invention can obtain similar effects even when used as a rotation speed control device for other types of internal combustion engines.

〔Effect of the invention〕

As explained above, the internal combustion engine rotation speed control device of the present invention can prevent the occurrence of periodic rotation speed fluctuations that are unpleasant to the human body by making simple changes to conventional similar devices, and can prevent internal combustion engine This has the effect of improving the rotational speed stability of an internal combustion engine at a low cost without considering individual engine differences, aging, or variations between cylinders.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing the configuration of the present invention, FIG. 2 is a configuration diagram of a diesel engine rotation speed control device that is an embodiment of the present invention, and FIG. 3 is a flowchart of arithmetic processing by the CPU in the above device. FIG. 4(a) is a diagram showing an example of measurement of the basic operation amount in the above device, and FIG. 4(b) is a diagram showing an example of measurement of the final operation amount in the above device. 8...Diesel engine, 9...Fuel injection nozzle,
10... Distribution type fuel injection pump, 11... Linear actuator (rotation speed control actuator), 12...
...Control unit (basic operation amount calculation means, target rotation speed setting means, minute disturbance generation means, operation amount output means), 51.
...Interface, 52...CPU, 53...
Memory, 13... Transistor circuit (drive signal output means), 14. Rotation speed detection upper sensor (rotation speed detection means), 1
5...Porium for target rotation speed setting means, 16...Starter switch

Claims (1)

[Claims] (1) A rotation speed detection means that outputs a signal according to the rotation speed of the internal combustion engine, a target rotation speed setting means that outputs a signal according to a predetermined target rotation speed, and an output of at least the rotation speed detection means. basic operation amount calculating means for performing calculations based on the signal and the output signal of the target rotation speed setting means and outputting a signal corresponding to the basic operation amount; a micro-disturbance generation means, an operation signal output means for correcting the output signal of the basic operation amount calculation means based on the output signal of the micro-disturbance generation means and outputting a final operation signal, and an output of the operation signal output means. A rotational speed of an internal combustion engine characterized by comprising a drive signal output means for outputting an actuator drive signal in response to a signal, and a rotational speed control actuator driven by an output signal from the drive signal output means to adjust the rotational speed. Control device.