JP2832295B2 - Duty solenoid control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a duty solenoid used for various control valves or driving devices of an automobile engine, for example, an idle speed control valve (ISC valve) for controlling an idle speed.

[Prior art]

2. Description of the Related Art Conventionally, a proportional solenoid is used as an actuator for various control valves of an automobile engine, such as an ISC valve disclosed in JP-A-59-128943 and JP-A-59-211741, for example. This means that the current value flowing through the coil and its stroke (lift) amount are approximately proportional. Generally, the current value is given in the form of a duty ratio of a predetermined pulse voltage, and the stroke amount is controlled by the duty ratio. doing. However, if the pulse voltage, that is, the battery voltage changes, the stroke amount of the solenoid also changes even at the same duty ratio.
For example, the opening degree of the ISC valve cannot be maintained as instructed (duty ratio). Therefore, the duty ratio D is calculated by using the following equation: D ← {(V _B14 −V ₀ ) / (V _B −V ₀ )} × D (1) V _B14 : Battery reference voltage (14V) V ₀ : constant considering the voltage drop of the transistor V _B: corrected as battery voltage detection value, the output stroke change of the solenoid due to battery voltage changes had to not occur.

[Problems to be solved by the invention]

Actually, the solenoid used has its magnetic characteristics or mechanical characteristics (friction, inertia) including the controlled object. Therefore, as shown in FIG. 3, the stroke amount 1 with respect to the duty ratio is equal to the actual battery voltage. with slope becomes gentle in accordance with V _B decreases from the battery reference voltage V _B14, disable the duty ratio d that does not output the stroke is obtained by applying a pulse voltage, the battery reference voltage battery voltage from d ₁ of V _B14 V D ₂ , d as _B decreases
_Increases to ₃ . Therefore, the error between the control command and the operation amount is large on the low stroke side, that is, on the small duty ratio side, and the controllability is deteriorated. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a duty solenoid control device capable of performing various controls by a duty solenoid with high accuracy and good controllability. .

[Means for solving the problems]

In order to achieve the above object, the present invention provides a control unit that drives a duty solenoid by a duty ratio control signal and determines a control target such as a valve with an output stroke according to the duty ratio. A slope correction value calculating means for calculating a slope correction value of the output stroke with respect to the duty ratio using a voltage or a battery voltage as a parameter; and an invalid duty ratio based on mechanical characteristics of the duty solenoid in accordance with the pulse voltage or the battery voltage. An invalid correction calculating means for calculating an invalid correction value for correction; and a valve control amount correction for multiplying the duty ratio by the inclination correction value and further adding an invalid correction value to correct the duty ratio characteristic of the duty solenoid. Configuration with means The is intended.

[Action]

Based on the above configuration, a pulse voltage or a detected value of a power supply (battery) voltage proportional to the pulse voltage is input to the slope correction value calculating means and the invalid correction value calculating means, and the duty which is a control amount in the pulse control amount correcting means is input. The ratio is multiplied by the calculated inclination correction value, and the calculated invalid correction value is added to correct the change in the duty ratio characteristic due to the power supply voltage fluctuation of the duty solenoid, and the fluctuation of the power supply voltage acts as a disturbance in the control system. To eliminate.

【Example】

Hereinafter, the present invention will be described with reference to FIGS. 1 to 5 by taking an ISC valve for controlling an idle speed as an example. In FIG. 1, reference numeral 1 denotes an engine, a water jacket provided around the cylinder thereof is provided with a water temperature sensor 2 for detecting an engine cooling water temperature Tw, and an injector 3 is provided near an intake port. The throttle valve 4 is provided with an idle switch 5 for detecting an idling state. The intake pipe is provided with a bypass passage 6 for bypassing the throttle valve 4, and an ISC valve 7 as valve means for regulating the intake air flow rate of the engine during idling is provided therein. The opening is set by the duty ratio ISC _duty of the duty ratio control signal given to the duty solenoid 7a for driving the ISC valve 7 by the control unit 8. The control unit 8 is composed of a microcomputer or the like, and together with signals from the water temperature sensor 2 and the idle switch 5, a crank angle sensor (engine speed sensor) 9, an intake air temperature sensor 10, an air flow meter 11, a boost pressure sensor
It takes in signals from the 12, O ₂ sensor 13, etc. to control the air-fuel ratio,
In addition to ignition timing control, idle speed control is performed. When the idle switch 5 detects that the throttle valve 4 is fully closed by the idle speed control, the control unit 8
Determines that the engine 1 has entered the idling state, sets a target idle speed Ni based on the engine cooling water temperature Tw detected by the water temperature sensor 2, further adds air conditioner correction, etc., and A duty ratio control signal is output to a drive circuit 15 composed of a power transistor or the like as shown in FIG. 2 in accordance with the deviation from the detected engine speed Ne. 7, a current (voltage V _B ) is supplied to the duty solenoid 7a, the output stroke amount 1 corresponding to the duty ratio ISC _duty of the control signal, that is, the valve opening is set, and the engine speed Ne is fed to the target idle speed Ni. Control the bag. Meanwhile, the duty solenoid 7a is the duty ratio ISC _duty and the stroke amount l of the duty ratio control signal, as shown in Figure 3 is substantially proportional to the pulse voltage and the voltage V _B is the reference voltage of the proportional battery 16 even when in the V _B14, the characteristic curve as described above occurs ineffective portion d ₁ without passing through the origin. Further, when the voltage V _B of the battery 16 is lowered, the inclination is moved in a direction to reduce the stroke amount l,
Ineffectiveness becomes larger than d ₁ of the reference voltage V _B14, e.g.
To V _B = 10V In d _2, increases and so the V _B = 6V in d _3. Variation due to such a decrease in the battery voltage V _B is
It means that greatly reduce controllability in duty ratio ISC _duty is small control area, the control unit 8 as shown in FIG. 4, the duty solenoid for correcting a characteristic change of the duty solenoid 7a due to variations in the battery voltage V _B A control function is provided. Next, the operation of the duty solenoid control function will be described with reference to the block diagram shown in FIG. 4 and the flowchart shown in FIG. The control unit 8 first detects the engine speed Ne, the engine coolant temperature Tw, and the air conditioner switch signal AC detected by the engine operating state detecting means 18.
(Step S100), and the duty ratio calculation means 20 calculates the duty ratio at the battery reference voltage _VB14 according to the deviation between the target idle speed Ni and the detected engine speed Ne as described above. ISC
_{The duty} is calculated (step S101). The control unit 8 inputs the battery voltage V _B detected by the battery voltage detection unit 19 (step S10
2), _{firstly, K V = (V B14 -V} 0 by the following equation, or by a map search and the inclination correction value K _V due to variations with respect to the reference voltage V _B14 of the battery voltage V _B in a tilt correction value calculating means 21) / ( V _B −V ₀ ) (2) Obtain (Step S103). Then the invalid correction value calculating means 22, ineffectiveness of the duty ratio ISC _duty by the detected battery voltage V _B d
An invalid correction value G _V for correcting the reads from a table set in advance in ROM or the like from the experimental results as of FIG. 3 (step S104). And in duty ratio correcting means 23, the first multiplication means 24 in the previously determined duty ratio ISC _duty ← ISC _duty × multiplied by the correction value gradient in ISC _duty K _V ... (3) are corrected inclination duty ratio ISC _duty Then, the invalidation correction value G _V is added by the addition means 25, and ISC _duty ← ISC _duty + G _V (4) A duty ratio ISC _duty in which the invalid part d is corrected is obtained (Step S106). The valve control amount ISC _duty corrected for inclination correction and invalidity correction is output to the drive circuit 15 (step S10
7) Drive the duty solenoid 7a. That way, even if changes battery voltage V _B is even, the opening is obtained of the ISC valve 7 according to the control amount, not the fluctuation of the battery voltage V _B acts as a disturbance of the control system, controllability is improves. Note in the above embodiment, according to the battery voltage V _B had been to correct the invalid portion of the duty ratio,
Regardless of the battery voltage V _B, disabling the correction value G _V be at least zero non-constant, be corrected so as to approach the origin center substantially the same effect is obtained with a practically, yet control unit 8
Can be simplified. In the above embodiment, the inclination correction value K _V and invalid correction value G _V, has been set as a function of the battery voltage as a parameter, which may be a pulse voltage of the battery voltage equivalent to the control signal.

【The invention's effect】

As described above, according to the present invention, the duty ratio of the control signal for driving the duty solenoid is corrected in accordance with the fluctuation of the battery voltage (pulse voltage), and the characteristic duty is corrected. Since this is added, disturbance in the control system due to fluctuations in the battery voltage (pulse voltage) can be eliminated, controllability is improved, and more accurate control can be performed.

[Brief description of the drawings]

1 is a configuration diagram of an idle speed control system to which the present invention is applied, FIG. 2 is a circuit diagram of an ISC valve having a duty solenoid, FIG. 3 is a characteristic diagram of an ISC valve, and FIG. FIG. 5 is a block diagram showing the configuration of the solenoid control system, and FIG. 5 is a flowchart showing the operation thereof. 7 ... ISC valve, 7a ... Duty solenoid, 8 ...
... Control unit, 16 ... Battery (power supply), 19 ... Battery voltage detection means, 20 ... Valve control amount calculation means, 21 ...
... Inclination correction value calculation means, 22 ... Invalid correction value calculation means, 23
... Valve control amount correction means.

Continuation of the front page (56) References JP-A-60-11649 (JP, A) JP-A-60-190637 (JP, A) JP-A-55-32918 (JP, A) JP-A-59-211741 (JP) , A) Fully open 1986-91679 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02D 41/00-45/00

Claims (1)

(57) [Claims] A control unit for driving a duty solenoid by a duty ratio control signal and controlling a controlled object such as a valve with an output stroke corresponding to the duty ratio, wherein at least a pulse voltage or a battery voltage of the duty ratio control signal is a parameter. A slope correction value calculating means for calculating a slope correction value of the output stroke with respect to the duty ratio; and an invalidity correction for correcting an invalid duty ratio due to mechanical characteristics of the duty solenoid according to the pulse voltage or the battery voltage. An invalid correction value calculating means for calculating a value; and a valve control amount correcting means for multiplying the duty ratio by the inclination correction value and further adding an invalid correction value to correct the duty ratio characteristic of the duty solenoid. Dew characterized It solenoid control device.