JPH0419340A - Speed control method for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve responsiveness and stability by determining a gain value in a target engine speed or PID computation based on an operation speed of an acceleration pedal and an acceleration operation quantity at that time, in a device which PID-control the opening of a throttle valve based on deviation from the target rotational speed. CONSTITUTION:When an acceleration pedal 7 is stepped down, a controller 6 detects a stepping quantity (acceleration opening A) based on a detection signal of an acceleration sensor, and an absolute value of a variation quantity of the acceleration opening A is computed, then a target speed of an engine 1 with respect to the acceleration opening A is set. The controller 6 then determines a gain value G1 (integration operation), GP (proportion operation), GD (differentation operation) used at the time of PID computation by the acceleration opening A and the variation quantity at that time. By using the deviation between the real engine speed N detected by an engine speed sensor 10 and the target engine speed and the gain value, the computation for the PID control is performed, and the opening of a throttle valve that is, the rotational direction and quantity of a step motor 5 are computer so as to adjust the opening of the throttle valve.

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.

[Prior Art] Conventionally, as a method of controlling the rotation speed of an internal combustion engine, there is a method of determining a deviation between an actual rotation speed (actual rotation speed) and a target rotation speed, and controlling the rotation speed based on the deviation. That is, the amount of depression of the accelerator pedal (accelerator opening degree) is determined, and the target rotation speed for the accelerator opening degree is set from data stored in advance in the storage device. Then, the deviation between the target rotation speed and the actual rotation speed of the internal combustion engine is determined, and based on the deviation, a PID calculation is performed for PID control with a constant gain value to determine the throttle opening, that is, an actuator that operates the throttle valve. The amount of movement is determined and the actuator is operated to control the rotation speed.

Another control method is to create map data of throttle opening relative to accelerator opening in advance for each load state of the internal combustion engine. Then, the accelerator opening degree and the load condition of the internal combustion engine are detected, the throttle opening degree under the accelerator opening degree and load condition is determined from the map data, the amount of movement of the actuator that operates the throttle valve is determined, and the actuator is activated to rotate the throttle valve. There are ways to control numbers.

[Problem to be solved by the invention] However, when controlling the rotation speed by determining the former deviation, although the program software for control is simple, the accelerator feeling is poor when considering stability during load fluctuations. On the other hand, if the accelerator feeling was improved, there was a problem in that stability during load fluctuations deteriorated.

Furthermore, the latter control method has better responsiveness and stability than the former. However, the map data requires a huge amount of data. Therefore, when the amount of data is reduced, the accuracy of the characteristic map decreases accordingly, resulting in problems such as poor controllability and the need to add functions for correction.

This invention was made to solve the above problems, and its purpose is to improve the responsiveness and stability of internal combustion engine rotation speed control using simple program software without using a huge amount of map data. It is an object of the present invention to provide a rotation speed control device for an internal combustion engine that can improve the rotation speed of an internal combustion engine.

[Means for Solving the Problems] In order to achieve the above object, the present invention calculates the deviation between the actual rotation speed of the internal combustion engine and the target rotation speed of the internal combustion engine based on the operation amount of the accelerator pedal, and uses the deviation. A method for controlling the rotation speed of an internal combustion engine, in which a PID calculation is performed for PID control, the calculation result is used as a throttle valve opening adjustment amount, and the rotation speed of the internal combustion engine is controlled by adjusting the throttle valve opening. The gist of this invention is that the operation speed of the accelerator pedal is determined, and the target rotation speed or the gain value in the PID calculation is determined based on the operation speed and the accelerator operation amount at that time.

[Effect] For example, when depressing the accelerator pedal to a predetermined position, the faster the operation speed, the lower the target rotation speed or PI.
The gain value in the D calculation increases. Conversely, the slower the operating speed, the smaller the target rotational speed or the gain value in the proportional integral.

As a result, it is possible to change the responsiveness according to the operation speed, and it is possible to improve the accelerator feeling while maintaining stability during load fluctuations.

[Embodiment] Hereinafter, an embodiment in which the internal combustion engine rotation speed control method of the present invention is embodied in an engine rotation speed control device will be described with reference to the drawings.

FIG. 1 shows a schematic diagram of a rotation speed control device for an internal combustion engine (hereinafter referred to as engine), and an engine 1 has an output shaft 2 connected to a load 3 for driving. A carburetor 4 is provided in the intake passage of the engine 1, and the carburetor 4 is provided with a step motor 5 that operates a throttle valve and adjusts its opening degree.

The controller 6 is composed of a microcomputer, and inputs a detection signal from an accelerator sensor 8 consisting of a potentiometer that detects the amount of depression of the accelerator pedal (accelerator opening degree), and also inputs a detection signal from an accelerator sensor 8 that detects the amount of depression of the accelerator pedal (accelerator opening degree). A detection signal from a rotation sensor 10 that detects the rotation speed (that is, the actual rotation speed of the engine 1) is input. The controller 6 has a built-in memory, and uses a program stored in the memory to control the engine rotation speed to calculate the direction and amount of rotation of the step motor 5 and drive and control the motor 5. There is.

Next, the operation of the rotation speed control device configured as described above will be explained with reference to the flowchart of the controller 6 shown in FIG.

Now, when the accelerator pedal is depressed to a certain amount, in step 101, the controller 6 determines the amount of depression based on the detection signal from the accelerator sensor 8 (
While detecting the accelerator opening degree A), step 102
The amount of change in the accelerator opening A (operating speed) dA/d
Calculate the absolute value of t. Subsequently, in step 103, a target rotation speed of the engine 1 for the accelerator opening degree A is set. This setting is based on the data of the target rotation speed for the accelerator opening degree A, which is pre-stored in the memory and determined through tests or theoretically.

Once the target rotation speed is set, the controller 6 sets the following gain values G, (integral action), GP (proportional action), and GD (differential action) to be used in the PID calculation to be performed later in step 104. seek.

G+ = f r (A+C+ l dA/ d
t l ) GP = f p (A+CP l d
A/dtl)GD=fD(A+Co
l dA/ d t l) In addition, CI, CP, CD
is a coefficient determined in advance through tests or theoretically.

In other words, each gain value G r for conventional PID control
, Gp, GD, each gain value is uniquely determined with respect to the target rotation speed, and the target rotation speed also depends on the accelerator opening A.
It was determined solely by

That is, each gain value was uniquely determined only by the accelerator opening degree A.

On the other hand, in this embodiment, each gain value G+
, Gp, Go are the accelerator opening A and the amount of change d at that time.
A/dt. In other words, the faster the operation speed, the larger the gain values Gr, Gp, GD, and the slower the operation speed, the larger the gain values GI, c, , G
D becomes smaller.

When each gain value is determined, in step 105, the actual rotational speed N at that time is determined based on the detection signal from the rotation sensor 10.
seek. Subsequently, the deviation between the actual rotation speed and the target rotation speed is determined in step 106 and 107, and the calculation for PID control is performed using the deviation and the gain value.
The opening degree of the throttle knob, that is, the direction and amount of rotation of the step motor 5 are calculated and determined. After determining the rotational direction and amount of rotation of the stem/tube motor 5, the process moves to step 108, where the controller 6 outputs a control signal to the stem/tube motor 5 to drive it in the determined rotational direction and amount. The opening degree of the throttle knob is adjusted by a step motor 6, and the rotation speed of the engine 1 is controlled.

In this way, in this embodiment, game 1' in PID control is
Since the gain values (lI, cyp, GD) are not kept constant and determined by the function G = f (A + Cl dA/d t l ), when the accelerator pedal is suddenly depressed, the gain values G+ , Gp , Go becomes large, and the control amount of the step motor 5 is relatively large, and the engine l is quickly controlled to the target rotation speed.On the other hand, when the accelerator pedal is gently depressed,
The gain values G+, GP, and GD become small, the control amount is also small, and the engine 1 is slowly controlled to the target rotation speed.

Therefore, the response speed can be changed depending on the speed of accelerator operation, and the accelerator feeling can be improved while maintaining stability during load fluctuations. Furthermore, since no map data is used, the data capacity is small and the process can be simplified, and a load detection sensor or the like is not required, so costs can be reduced.

It should be noted that the present invention is not limited to the above embodiment, and in the above embodiment, the amount of change dA/d of the accelerator pedal 7
Although t is used to determine the gain value in PID control, the amount of change dA/dt may be used as an element for determining the target rotation speed.

That is, as shown in FIG. 3, in steps 200 and 201, the accelerator opening degree A and the amount of change dA/d
Find t. Next, the process moves to step 202, where a target rotational speed is set for the absolute value of the accelerator opening degree A and the amount of change dA/dt.

That is, D=f (A+K l dA/d t l) where K is a coefficient determined in advance through testing or theoretically.

Next, in step 203, the actual rotational speed of the engine 1 is determined, and in steps 204 and 205, the deviation between the actual rotational speed and the target rotational speed is determined, and the PID is set to a constant gain value based on the deviation. A calculation for control is executed, and the rotation direction and rotation amount of the step motor 5 are calculated and determined. Then, in step 206, similarly to the embodiment described above, the controller 6 outputs a control signal to the step motor 5 to drive it in the determined rotation direction and rotation amount. The opening degree of the throttle valve is adjusted by a step motor 6, and the rotation speed of the engine 1 is controlled.

Therefore, even in this case, when the accelerator pedal is suddenly depressed, the target rotational speed fluctuates and the deviation becomes large compared to the conventional case, as shown in FIG. 4, and the control amount of the step motor 6 also changes accordingly. The engine 1 is controlled to the target rotation speed relatively quickly. On the other hand, when the accelerator pedal is depressed gently, the target rotational speed fluctuates smaller and the deviation becomes smaller, and the control amount is smaller and the engine 1 gradually reaches the target rotational speed than when the accelerator pedal is depressed suddenly. controlled by.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to improve the responsiveness and stability in controlling the rotation speed of an internal combustion engine using simple program software without using a huge amount of map data. It has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining an engine speed control device embodying the present invention, FIG. 2 is a flowchart for explaining the operation of the controller, and FIG. 3 is a detailed diagram for explaining the present invention. FIG. 4 is a flowchart showing the operation of the controller for this purpose, and FIG. 4 is a diagram showing the relationship between the accelerator opening degree and the target rotation speed. Internal combustion engine 1, output shaft 2, load 3, carburetor 4, step motor 5, controller 6, accelerator pedal 7, accelerator sensor 8, flywheel 9, rotation sensor 10° Patent applicant Toyota Industries Corporation. agent
Patent Attorney On 1) Hironobu (and 1 other person) (A) Question q

Claims (1)

[Claims] 1. The deviation between the actual rotational speed of the internal combustion engine and the target rotational speed of the internal combustion engine based on the operation amount of the accelerator pedal is determined, and the deviation is used to perform PID calculation for PID control, and the calculation result is used to calculate the opening of the throttle valve. In an internal combustion engine rotation speed control method in which the rotation speed of the internal combustion engine is controlled by adjusting the opening degree of the throttle valve, the operation speed of the accelerator pedal is determined, and the operation speed and the accelerator operation amount at that time are calculated. A rotation speed control method for an internal combustion engine, wherein the target rotation speed or a gain value in PID calculation is determined by: