JPS61233814A - Position controller - Google Patents

Abstract

PURPOSE:To prevent hunting and to cope with a steady-state or temporary fluctuation of the operating characteristic by deciding the propriety of correction based on a position change and applying correction with a correction amount integrated from the initial value when no correction is required. CONSTITUTION:A basic controlled variable deciding means 6 decides a basic controlled variable corresponding to a position deviation between an actual position of an object 1 to be controlled detected by a position detection means 3 and an object position set by an object position deciding means 4. A position change amount detection means 7 detects the position change at each prescribed period, a comparison means 8 compares that the position change is a prescribed value or below so as to discriminates the propriety of correction, a correction amount deciding means 10 generates a correction whose value is changed in terms of integration at each generation of an output of required correction and the correction amount is reset to the initial value corresponding to the decision output representing unnecessity of correction of the comparison means 8 by a reset means 11. A drive signal generating means 9 controls the basic controlled variable by generating a drive signal corresponding to the controlled variable corrected by the correction amount.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a position control device that performs feedback control of, for example, the opening position of a throttle valve of an engine to a target displacement I.

[Prior art]

As a conventional device of this kind, for example, Japanese Patent Application Laid-Open No. 58-62
As shown in Publication No. 336, the pressure servo is adjusted so that the actual throttle valve opening displacement lid matches the target amount displacement position determined based on the rotation speed deviation between the detected rotation speed and the target rotation speed of the engine. The solenoid valve in the air and negative pressure introduction passage to the motor's operating pressure chamber is turned ON and OFF by a duty pulse signal according to the positional deviation between the target amount rfL position and the actual opening position.
It is known that the throttle valve opening position is controlled by driving the throttle valve.

[Problem that the invention seeks to solve]

By the way, the duty pulse signal corresponding to the position deviation given to the solenoid valve for this feedback position control can be adjusted to the pressure in the operating pressure chamber of the pressure servo motor by appropriately setting the pulse width characteristic with respect to the position deviation. This is an effective technology in that it responds to positional deviation (change speed f') and increases responsiveness while reducing control hunting during feedback control. Since the valve drive pulse width versus actual valve opening period characteristic varies due to manufacturing variations and aging, even if the pulse width characteristic for the above position deviation is set to an appropriate characteristic, the throttle valve drive amount for the pulse width will vary. varies, and for this reason, it has been difficult to optimally balance increasing control responsiveness and preventing hunting. In other words, solenoid valves do not operate at all below a predetermined pulse width, and even for solenoid valves of the same model, the start pulse width varies due to manufacturing variations and aging, and furthermore, due to power supply voltage fluctuations, disturbances, etc. Therefore, in the region where it is originally necessary to drive the solenoid valve, especially in the region where the positional deviation is small and the pulse width is small, even though the drive pulse signal is given, the There are problems such as the solenoid valve not operating or the opening time being too short, making it impossible to control the position within the target position range, or taking too much time to converge within the target position range. In order to deal with this, if the characteristics of the pulse width with respect to the positional deviation are set so that the pulse width becomes large, there is a problem in that hunting is more likely to occur.

[Means for solving problems]

Position control device according to the present invention [Basic control amount determining means for determining a basic control amount for controlling the position of a controlled object b based on a positional deviation between a one-digit target position and an actual position, and a control object within a predetermined period of time] The amount of change in position? a comparison means for detecting and comparing the position change amount with a set value to determine whether correction is necessary; and means for generating a correction amount whose magnitude sequentially changes in an integrated manner in response to the output indicating the need for correction; The device includes means for resetting the correction amount to an initial value in response to the output that does not require correction, and driving the controlled object based on the control amount obtained by correcting the basic control amount by the correction amount.

[Effect]

In this invention, the amount of change in the position of the controlled object is detected every predetermined period based on the actual position detection output of the controlled object,
This position change amount is compared with a set value to determine whether correction is necessary, and a correction amount whose size changes sequentially in response to the occurrence of an output that requires correction is determined, and this correction amount does not require the above correction. The value is reset to the initial value in response to the judgment output of Even if the drive state (position change state) of the controlled object by the control amount does not reach the expected drive state, the basic control amount is corrected according to the state, preventing hunting while ensuring responsive and reliable control. In addition, the correction amount changes cumulatively each time the controlled object does not make the planned position change, and is reset when the planned position change occurs, so the position deviation is particularly small. In the vicinity of the target position if, the correction amount is stabilized by being controlled to follow the steady fluctuations and temporary fluctuations of the operating characteristics of the drive means, while preventing hunting in the control without giving a correction amount more than necessary. Reliable position control becomes possible.

〔Example〕

FIG. 1 shows the overall configuration of a position control device according to the present invention. This is a block diagram, in which (1) is a controlled object such as a throttle valve of an engine, and (2) is a negative pressure servo motor for driving this controlled object, for example, and a solenoid valve that controls its driving pressure. (3) driving means consisting of, etc.;
is a position detection means for detecting the actual position of the controlled object (1), and the detected actual position and the target position set by the target position determination means (4) are determined by the drive mode determination means (5). Comparison calculation is processed and the controlled object (
1) The drive direction (for example, the open drive mode or the close drive mode for the throttle valve) is determined. The basic control amount determining means (6) performs the basic control I! on the driving means (2) in response to the positional deviation between the actual □ position and the target position. − is determined. On the other hand, the position change amount detection means (7) detects the position change amount f of the controlled object (1) every predetermined period based on the detected force of the position detection means (3), and the comparison means (8) detects this detected force. The correction amount determining means αQ determines whether correction is necessary by comparing whether the position change amount is less than a predetermined change amount, and the correction amount determining means αQ generates a correction tfg whose magnitude changes cumulatively every time an output requiring correction is generated. Moreover, this correction amount is determined by the reset means αp.
is reset to the initial value in response to the determination output from the comparison means that no correction is necessary. The drive number generation means (9) generates and generates a drive number corresponding to the control amount obtained by correcting the basic control amount by this correction amount, thereby controlling the drive means (2). In this way, by correcting the basic control amount based on the positional deviation by the correction amount based on the amount of position change within a predetermined time and determining the control amount for the drive means (2), it is possible to temporarily adjust the control target (1) by the basic control amount. ) even if the scheduled driving is not possible, the correction amount determining means αO determines the state and corrects the control amount as much as possible to achieve the planned driving state, thereby preventing control hunting and improving responsiveness. , the control object (1) can be reliably controlled within the target position range. Furthermore, the value of the correction amount changes in an integrated manner in response to the determination output that correction is required based on the amount of position change, and the value is reset by the determination signal that does not require correction, so that the value of the driving means is The amount of correction is controlled by following both steady and temporary fluctuations in operating characteristics.
Even with these fluctuations, reliable position control is always possible, and feedback control without hunting is also possible without the correction amount becoming too large especially near the target position.

FIG. 2 shows the entire W factor showing an example of this invention,
An example of application to engine speed control is shown.

In Fig. 2, (loo) is an internal combustion engine, which has an engine body (loo&) and a throttle valve (100'N) arranged in the intake passage. (102) is an ignition device that ignites this engine. The rotational speed number based on the opening/closing signal of the primary circuit of the ignition coil is input to the control device (103). (104) is a target rotational speed setting device for arbitrarily setting the target engine rotational speed. It is composed of a variable resistor, etc., and generates a signal whose value is 6 times the set rotation speed. (105) is a pressure servo motor that drives the throttle valve (100b), and is controlled by the pressure in the operating pressure chamber (105a). A correspondingly displaced diaphragm (105b)'fr
This working pressure chamber (105a) is connected to a negative pressure source (106) and (107)f through negative pressure side and atmospheric side solenoid valves (106) and (107)f, respectively.
Each passage is provided with an orifice (108), (109), and a surge tank (110) is provided in the negative pressure passage to compensate for pressure fluctuations.
is provided. (111) is a position sensor for detecting the position of the throttle valve, and is made of, for example, a variable resistor, and is integrated with a pressure servo motor to detect the displacement position of the diaphragm (105b), and its output is controlled by the control described above. It is input in the body @ (103). This control device (LO3) is mainly composed of a microcomputer, and further includes the rotation speed setting device (104), an A/D converter that converts the analog voltage deviation of the position sensor (Ill) to 8f digital, and each of the electromagnetic valves ( 106), (10
7) includes a transistor circuit for controlling power supply fON/OFF. The atmosphere side solenoid valve (106) is a normally open solenoid valve that opens at power supply 077, and also has negative pressure [1
11 solenoid valves (106) are normally closed ° solenoid valves, and each solenoid valve (106), (107) is in throttle open side drive mode, throttle close side drive mode, and throttle hold mode. As shown in (ON, 077 combination drive).

4 and 5 are operational flowcharts of the program stored in the ROM of the microcomputer in the control device (103), and the operation will be explained according to the figures.

The control body [(1O3) executes the processing shown in FIG. 4 according to the program stored in the ROM. That is, first, in step (201), the target position (Po) is read and the target position is set. This target position (Pa) is the fifth
It is determined by calculations in another processing routine shown in the figure. That is, in step (501), the engine speed (N) detected by measuring the period of the ignition signal of the ignition device (102) whose frequency is proportional to the engine speed is read;
In step (502), the target rotation speed setting device (10
4) The target rotation speed (No') set in step 4) is read, and in the next step (503), proportional and integral calculations are performed as appropriate based on the rotation speed deviation between the detected rotation speed (N) and the target rotation speed (NO). , or perform differential processing to obtain the target position ti#
(Po) is determined, and this determined target position (Po)
is read in the above step (201). Next, in step (202), the previous throttle position ff(Pn-1), which is stored in the P register of the RAM and will be discussed, is transferred to another LP register and stored, and then in step (203), the current throttle position ff(Pn-1) is transferred to another LP register and stored. Throttle position (Pn)? This throttle position (P) read into the above P register is determined by the position sensor (111
) is the detection data obtained by performing Mu/D conversion on the output voltage of the output voltage.

In the fifth step (205), the mode data indicating any of the open, closed side, and dead zone modes previously determined and stored in the dMOD register in step (204) is transferred to the LMOD register and stored. The position deviation (Po-Pn) between the read target position 111 (Po) and the throttle position IF (Pn) of the P register is the 6th
The dead zone within the specified range shown in the figure (open side dead zone, closed side dead zone (DP)
O) (DPO)) is determined, and if it is within the dead zone, data indicating this is stored in the above Mo1) register (step (206)). In this dead zone mode, step (207'') is performed. Then, as shown in Fig. 3, the atmospheric side solenoid valve (107) is turned on and closed, and the negative pressure side solenoid valve (106) is turned off and closed to reduce the operating pressure of the pressure servo motor (105). The pressure in the chamber (105a) is maintained at the current value and the throttle valve (lOOb) is
1f is held at the current value. Then step (208
) to detect whether or not the retention time has been completed, but in this case, the retention time has not been set and it is determined that the retention time has been completed, and the process returns to the first step (201).
Proceeding to step (205) via steps (202), (203), and (204), it is determined again whether or not there is a dead zone. If it is a dead zone, data indicating the dead zone is stored in the MOD register, and the dead zone is set. is maintained, the solenoid valves (106) and (107) both close, and the throttle valve (100b) maintains the holding mode.

On the other hand, in step (205) above, the positional deviation (po
-Pn) exceeds a predetermined range indicating a dead zone, the process proceeds to step (209), where the polarity of the positional deviation (Po-Pn) is detected, and the actual throttle opening position (Pn) is adjusted to the target amount displacement al( In step (210), the atmospheric side solenoid valve (1
07) Set the throttle opening drive mode to close the f valve and open the negative pressure ml solenoid valve (106''), and in step (211) store data indicating the park opening drive mode in the MOD register.

Conversely, when the actual throttle opening position (Pn) is larger than the target amount displacement IF (I'o), in step (212) the closed side drive mode (atmospheric side solenoid valve (107) f open, negative pressure ( To) Set the solenoid valve (106) to closed), and
Data indicating the closed side drive mode is stored in the OD register.

Solenoid valves (106) and (107) are driven in accordance with the determination of the drive mode based on the polarity of this positional deviation (Po-P).
The next step (214) is to determine the driving time of (zls
This is done by L(216)K. That is, step (21
4) At the position deviation (PO-P) K corresponding to the 6th
Based on the characteristics shown in the figure, the basic pulse width is calculated (by a property map or calculation), and in the next step (215), a pulse width correction calculation, which will be described later, is performed. The drive time indicating the pulse width is set in the timer register (step (216)).
) The fifth step (217
), it is detected whether or not this set drive time has been completed, and the above-mentioned open side,
Alternatively, each solenoid valve (xo6), (xo7) is driven corresponding to the closed side set solenoid, and the pressure servo motor (
105) operating pressure of the throttle valve (loo'b)'r
It is controlled so that it approaches the target position.

When the driving time is completed, the process advances to step (218), where the preset holding time (THLD) is set in another timer register, and in the next step (20?), each solenoid valve (lo6), (1oF) is set in the holding mode ° (both solenoid valves (1o6) and (1o7') !d are closed), and in the next step this holding time (THILD
) has elapsed or not. This retention time (T
HLD) is a negative pressure servo motor (10
Since the pressure in the main operating chamber (105b 1 of 5) fluctuates with a delay, it is set in accordance with the time until this pressure fluctuation stops and stabilizes.
The maximum pulse width above the predetermined position deviation shown in the figure (TPWO2
)(Tpwaz) is set to zero.

When this holding time (THLD"l) is completed, the program returns to the first step (201) and repeats the program of each step. Therefore, if the position deviation (Po - P) is in a mode other than the dead zone, it corresponds to this position deviation. The pulse width determined by the characteristics shown in Figure 6 is the set holding time (TH
LD ) is applied to the solenoid valves (U06) and (107), and the throttle opening displacement @(P) is the target opening position (Po).
When the position deviation (Po-P) falls within the dead band range, the solenoid valves (106) and (107) are both closed to maintain the operating pressure of the pressure servo motor (105). , feedback control is performed to stop driving the throttle valve (LOOB).

The aLt pulse width calculated in the above step (215) is proportional to the positional deviation as shown in the positional deviation (FO-P) vs. pulse width characteristic in FIG.
The characteristics are set to take hunting into consideration, but as mentioned above, for example, a solenoid valve has a region in which it does not operate below a predetermined drive pulse width, and even if the solenoid valve is of the same type, this region may vary due to manufacturing variations. For example, the 6th
Opening side and closing side pulse width (TPWOt) (TPWOs) set at the boundary of dead zone of feedback control in the figure
Even if the solenoid valve is given, there are problems such as the solenoid valve does not open or close for the scheduled period, and feedback control to the target position range is not possible or the responsiveness decreases. This problem can be effectively improved by the pulse width correction function.

Rσ, FIG. 7 shows the above pulse width correction calculation step (21
5), and the operation of the pulse width correction calculation will be explained with reference to the same figure.

First, in step (301), the current drive mode (open side or close side drive mode) data stored in the MOD register and the previous drive mode ° (open side, close side drive mode) stored in the LMOI) register are combined. , or dead zone mode) data, and if they are equal, that is, if they have been in the same mode continuously, in the next step (302) it is determined whether the current drive mode is the open side or not. is detected and is in open side drive mode, proceed to the next step (
303), the amount of change in position due to the difference between the current throttle position (Pn) stored in the P register and the previous throttle position (Pn-1) stored in the rJP register is determined from the set value (KSO). If this open side drive mode is used two or more times in a row, the current throttle position (Pn) and the previous throttle position (pn-x) are Since the data value is synchronized with the start time of each drive pulse, the amount of change in throttle position during the period from the start of the previous drive pulse to the start of the current drive pulse is compared with the set value and determined. Therefore, in step (303), it is determined whether or not the throttle position has changed by a set amount in the valve opening direction due to the previous opening drive pulse. As a result of this judgment, if the amount of position change is less than the set value, step (30
4), the correction change amount storage memory address (KPwcO
) Corrected change pulse width (PWCO) stored in advance
is read and stored in the corrected pulse width memory register (OMP).
O) K Add to the correction pulse width stored up to now,
This added value is written (updated) in the correction pulse width register (C!MPO). Therefore, in this step (304), the correction change pulse width (pwco) is added sequentially every time there is an instruction to correct the pulse width in the open side drive mode, and the correction pulse width (Σpwco) in the register (CMPO) is added.
increases cumulatively.

In the next step (305), the control pulse width is calculated by adding the correction pulse width (ΣPWOO) of the register (OMPO) to the basic control pulse width determined in step (214) in FIG. Therefore, if the throttle valve (100b) does not move the planned amount in the opening direction due to the previous opening drive pulse, the correction pulse width of the register (CMI'O) is corrected to be larger than the previous value, and the correction is further increased. Since it is performed cumulatively, it is possible to correct the drive pulse width to a value that provides the planned movement of the throttle valve, and it is also possible to reliably correct the drive pulse width by following various variations in the operating characteristics of the electromagnetic valve. This cumulative change in the correction pulse width causes the position change amount of the throttle valve (100b) to change to the set value (K
ElO), it is determined in the above step (303), and upon receiving this determination output, the next step (306
), open-〇 correction pulse width register (OMPO)
The correction pulse width of the correction pulse width register (CMPC) on the closing side is reset to the initial value (zero) K, and the next step (31
0), a pulse width equal to the basic control pulse width is determined as the control pulse width. If the amount of position change does not move by the expected value again by resetting the correction pulse width to the initial value in step (306), step (306)
Based on the output of step 3), cumulative addition correction of the correction pulse width is performed in step (304), and the drive pulse width increases again.

In this way, the corrected pulse width is adjusted to the throttle valve (1oo
If b > does not move by the planned amount, it will increase cumulatively,
If it moves by the planned amount, it is reset to the initial value, and as a result, if it does not move by the planned amount, it repeats the cumulative increase and change, and the drive pulse width is controlled in response to the change in the pawl pulse width. Therefore, the correction pulse width never increases too much, thus reliably preventing control hunting,
Moreover, the position can be controlled to the target position.

On the other hand, if it is determined in the above step (302) that the current drive mode is the closed side drive mode following the previous time, in step (307) the difference between the previous throttle valve position and the current throttle valve position (position amount of change) is the set value (
It is determined whether or not it is larger than KEIC), and if it is small, in step (30J3), the correction change pulse @ (Pwcc) stored in the correction change amount storage memory address (xpwcc) is read out and corrected. Add it to the corrected pulse width stored up to now in the pulse width storage register (CMPC), and store this added value in this register (
cMPe) and write (update) the closed-side correction pulse width (
xpwcc) is determined, and in step (309), the basic control pulse width is added to the corrected control pulse width (XPWC!).
If it is determined that the throttle valve (loo'b) has changed its setting in step 07), the process proceeds to step (306) and resets the correction pulse width to the initial value, and in the next step (310) the basic control pulse Let the width be the driving pulse width.

In step (301) above, if the current mode is in the open or close (Il) dynamic mode and the previous mode is different from the current one, the current open or close drive pulse is the first in that mode. Therefore, there should be no predetermined position change amount between the previous time and this time.
Proceeds to step 3 and the basic pulse width is not corrected.

FIG. 8 shows a time chart in the open side drive mode where the throttle position (see FIG. 8(a)) is smaller than the target throttle position, and shows the time chart at each time (tD), (tt
), (tz), respectively, the basic control pulse width (TPWI) (TI'W2) (TPWI) determined in step (214) corresponding to the position deviation at that time.
Opening (ill driving pulses are generated and h is generated.The pause time between each driving pulse is a fixed time (THLD) set in the above step (218) (see FIG. 8(b)). This drive pulse is applied to the negative pressure side solenoid valve (106)
Turn on the power supply.

On the other hand, the atmospheric side solenoid valve (107'') is powered (ON) (see Fig. 8(c)) and closed, and the operating pressure chamber (105a) of the pressure gas servo motor (105) is closed.
) is the pulse width of the driving pulse ('rPW3) (TPT2
) (TPWI), the negative pressure side solenoid valve (106
) communicates with a negative pressure source of the surge tank (110),
The operating pressure gradually increases in the negative pressure direction with a predetermined delay every time a drive pulse is generated, and in response to this pressure change, the pressure servo motor (1o5) increases the opening position of the throttle valve (100b) (Fig. 8). By the way, even if a drive pulse with the drive pulse width (TPW2) is applied, the negative pressure side solenoid valve (105) does not open, and the operating pressure does not change depending on this pulse, as shown in Fig. 8(a). If the throttle opening rIIL position does not change as shown by the broken line, step (304) in FIG.

By correcting the basic pulse width using the corrected pulse width (Σpwao) in (305), the next driving pulse width becomes TPW.
3+, Σpwco = TPW4, (Fig. 8('
b)) by opening the magnetic valve (106) to control the throttle opening position within the target position range. In addition, time (t3)
In this case, the throttle opening position is at the target position of 111m (
This shows that the solenoid valves (106) and (107) are both open, indicating that the vehicle has entered the dead zone mode.

Even if the position deviation vs. drive pulse width is set near the optimum value in consideration of feedback control response and hunting as shown in Figure 6, for example, variations in solenoid valves, aging, and even temporary Due to voltage fluctuations, disturbances, etc., the operating characteristics of the solenoid valve fluctuate steadily or temporarily, making it impossible to obtain the expected control characteristics, but the position change of the throttle valve (105) within a predetermined time The necessity of correction is determined by comparing the amount with the set value, and the drive pulse width is corrected and controlled by the correction pulse width that changes sequentially in an integrated manner in response to the correction output and is reset by the correction output. Can effectively improve problems.

In the above embodiment, the amount of change in the throttle valve opening position within a predetermined period of time is compared with the set value to determine whether or not the pulse width needs to be corrected, and the amount of change in setting correction is added for each instruction indicating the need for correction. Although the correction amount is generated in an integrated manner, it is also possible to set in advance a correction amount whose value changes in an integrated manner in response to the number of times correction is required, and to read this out and use it as the correction amount. . Further, the driving means is not limited to the one in which the pressure passage of the pressure servo motor is controlled by a solenoid valve as in the above embodiment;
For example, it can be applied to a DC motor that is reversibly driven by pulse width control.

〔Effect of the invention〕

As described above, the present invention uses a feedback basic control amount determined based on the positional deviation between the actual position and the target position of the controlled object by a correction amount determined based on the amount of change in position of the controlled object within a predetermined time. Since the drive control of the controlled object is performed by making corrections, even if the drive state of the controlled object based on the basic control amount differs from the planned driving state, the basic control amount can be corrected in accordance with the state. , Feedback control to the target position is possible with good responsiveness and certainty while preventing control hunting. In addition, since the correction amount is controlled so that its magnitude changes sequentially and cumulatively in response to the output of the determination that correction is necessary, the correction amount can be controlled in response to fluctuations in the operating characteristics of the drive means. More reliable position control is possible, and since the correction amount is reset to the initial value by the judgment output that does not require correction, the correction amount can be adjusted to follow temporary fluctuations such as power supply voltage fluctuations and disturbances. The controlled correction amount is reset as soon as the controlled object moves as planned, so the correction amount never increases too much. Therefore, while reliably preventing the hunting operation of position control, the control target position The position can be controlled against.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the overall configuration of this invention, FIG. 2 is a configuration diagram showing one embodiment of this invention, and FIG.
FIG. 4 is a diagram of the operating state of the solenoid valve shown in FIG. 5 and 7 are calculation flowcharts of the control device shown in FIG. 2, FIG. 6 is a diagram showing its operating characteristics, and FIG. 8 is a time chart for explaining its operation. In the figure, (1) is the controlled object, (2) is the drive means, (3) is the position detection means, (4) is the target position determination means, (5) is the drive mode determination means, and (6) is the basic control amount determination. means, (7)
I-1'' position change amount determination means, (8) comparison means, (
9) is drive signal 8 constant generating means, αO is correction amount determining means, αυ
is a reset means. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A driving means for driving a controlled object, a position detecting means for detecting the actual position of the controlled object, and a basic control for controlling the driving means based on a positional deviation between the actual position detected by the position detecting means and a target position. basic control amount determining means for determining the amount; position change amount detection means for detecting the amount of position change of the controlled object within a predetermined period based on the output of the position detector; means for determining whether or not correction is necessary based on the amount of positional change determined; correction amount determining means for determining a correction amount whose magnitude changes sequentially and cumulatively in response to the correction necessity determination output; a reset means for resetting the magnitude of the correction amount to an initial value based on the basic control amount and the correction amount; and a drive signal generating means for controlling the drive means with a control amount determined from the basic control amount and the correction amount. Control device.