JP4978517B2 - Control device and control method for hydraulic actuator - Google Patents

Description

  The present invention relates to control of a hydraulic actuator, and more particularly to control for driving a plurality of actuators with the same hydraulic power source.

  In order to improve the fuel efficiency performance and environmental performance of an internal combustion engine, a variable valve mechanism that variably controls the opening / closing timing of an intake valve and an exhaust valve using an actuator is known.

  In Patent Document 1, as a control device for a variable valve mechanism using a hydraulic actuator, anti-windup countermeasures, that is, when the actuator operating speed is saturated, the feedback compensator accumulates an extra integral value and the control performance deteriorates. In order to prevent this, when the actual valve timing moves in the same direction as the target valve timing, the integration by the integrator is stopped when the speed of the actual valve timing becomes equal to or higher than the saturation determination threshold value.

  The reason why the integration is stopped in this manner is to prevent accumulation of excess integration because the saturation element is included in the control target. According to this control device, overshoot is reduced and control performance is improved by controlling a single actuator, for example, when a variable valve mechanism is provided only in an intake valve.

On the other hand, as a control device for driving a plurality of actuators by the same hydraulic power source, Patent Document 2 compares the target control range with the current position of the working device according to a preset command current-control amount characteristic. In addition, there is disclosed a control that performs the same operation as in the single operation by performing learning when it is out of the target control range.
JP-A-11-132164 Japanese Patent Laid-Open No. 11-181836

  When both the intake valve and the exhaust valve are provided with variable valve mechanisms and the plurality of actuators are driven by the same hydraulic pressure source, the saturation level such as the conversion angular velocity becomes smaller than that in the case of a single actuator. For this reason, in the control disclosed in Patent Document 1, there is a possibility that the operating speed of the actuator may not increase beyond the saturation determination threshold. In this case, the determination to stop integration is not performed, so that a large overshoot occurs and the control performance deteriorates.

  In addition, in the control disclosed in Patent Document 2, although the interference of hydraulic pressure caused by operating a plurality of actuators is taken into consideration, the state before the saturation element reaches saturation is assumed. Not considered.

  Therefore, when operating a plurality of actuators with the same hydraulic pressure source, if the saturation characteristic changes due to the interference of the hydraulic pressure, deterioration of the control performance cannot be prevented by either control of Patent Document 1 or Patent Document 2. .

  Therefore, an object of the present invention is to eliminate the problems in operating a plurality of actuators with the same hydraulic pressure source.

  The present invention includes a plurality of hydraulic actuators having a saturation element, one hydraulic source for driving the plurality of hydraulic actuators, and a plurality of control systems for matching control amounts of the plurality of actuators to different target values. , A feedback compensation calculation means provided for each control system that includes at least an integrator and calculates a feedback compensation output based on a deviation between an actual control amount and a target value, and another system And a saturation determination threshold value calculation means for determining a saturation determination threshold value of the own system based on the estimated speed, and the feedback compensation calculation means is based on the saturation determination threshold value. Determines whether the speed of the control target of the own system is saturated, and stops the integrator when the speed of the control target of the own system is saturated That.

  According to the present invention, since the saturation determination threshold value when hydraulic interference is received is determined based on the estimated speed of the control amount of the other system, an accurate timing when the speed of the control target of the own system is saturated. The integration can be stopped by this, whereby the deterioration of controllability can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a variable valve mechanism system to which this embodiment is applied. This variable valve mechanism is a mechanism for variably controlling the opening / closing timing of the intake valve and the exhaust valve of the internal combustion engine. VTCA and VTCB in FIG. 1 are intake side and exhaust side variable valve mechanisms (hydraulic actuators), respectively. Since the intake side variable valve mechanism VTCA and the exhaust side variable valve mechanism VTCB have the same configuration, the configuration will be described using the intake side variable valve mechanism VTCA.

  1 is a camshaft drive sprocket (hereinafter referred to as cam sprocket), 2 is a camshaft, 3 is a housing, 4 is a vane comprising a cylindrical portion 4a and blades 4b, 7A is a solenoid valve, 8A is a conversion angle positioning control controller, 11A is a camshaft position sensor. In addition, although the vane 4 is demonstrated as a 3 blade | wing, it is not necessarily restricted to this. Further, the attachment position of the camshaft position sensor 11A may be a position where the rotation position of the camshaft 2A can be detected.

  The housing 3 includes a vane 4 that is rotatable relative to the housing 3 inside. The end surface of the vane 4 is connected to the end surface of the camshaft 2 by a connecting pin or the like. A cam sprocket 1 is attached to the end surface of the housing 3 with bolts or the like. The cam sprocket 1 rotates in synchronization with a crankshaft (not shown) when a timing chain or the like is wound around.

  The solenoid valve 7A communicates with the retard chamber 6 and the advance chamber 5 through the retard chamber oil passage 17A and the advance chamber oil passage 16A, respectively, and is controlled by a VTC conversion angle positioning controller 8A described later.

  In the movement space of each vane 4b of the vane 4 in the housing 3, a retarding chamber 6 for applying hydraulic pressure in a direction to return the valve timing of the intake valve to the initial state with respect to the vane 4 with each vane 4b interposed therebetween, and the vane 4 On the other hand, an advance chamber 5 is provided in which hydraulic pressure is applied in a direction to change the valve timing of the intake valve to the advance side.

  A retard chamber oil passage 17A is connected to the retard chamber 6 and this retard chamber oil passage 17A is connected to one port (retard chamber port) of the solenoid valve 7A. The advance chamber oil passage 16A is connected to the advance chamber 5 and this advance chamber oil passage 16A is connected to one port (advance chamber port) of the solenoid valve 7A. The solenoid valve 7A is connected to a supply oil passage 14A for introducing oil sucked up by an oil pump 10 as a hydraulic pressure source from the oil pan 9 and a recovery oil passage 15A for returning the oil to the oil pump. ing.

  Note that the supply oil passage 14A of the variable valve mechanism VTCA and the supply oil passage 14B of the variable valve mechanism VTCB are branched pipes 14 connected to the oil pan 9, and the recovery oil passage 15A, The same applies to 15B.

  The solenoid valve 7A can realize three flow path patterns. As shown in FIG. 1, the first is a pattern in which the supply oil passage 14A and the advance chamber oil passage 16A, and the recovery oil passage 15A and the retard chamber oil passage 17A communicate with each other. According to this pattern, oil is supplied to the advance chamber 5 and the vane 4 rotates in the direction of the retard chamber 6, and the oil in the retard chamber 6 is retarded chamber oil passage 17A and recovery oil passage 15A. Return to the oil pan 9 through. The second is a pattern that does not allow any oil passage to communicate. According to this pattern, there is no movement of oil, so the position of the vane 4 remains fixed. The third pattern is a pattern in which the advance chamber oil passage 16A and the recovery oil passage 15A, and the retard chamber oil passage 17A and the supply oil passage 14A are communicated with each other. According to this pattern, the vane 4 rotates in the advance chamber 5 direction, contrary to the first pattern.

  In the variable valve mechanism VTCA, the vane 4 is rotated in the housing 3 by hydraulic control by the solenoid valve 7A as described above, thereby changing the phases of the camshaft 2 and the cam sprocket 1 to open / close an intake valve (not shown). Change the timing (hereinafter referred to as valve timing). That is, the valve timing of the intake valve can be changed by changing the relative rotation position (conversion angle) of the vane 4 with respect to the housing 3.

  The operation of the solenoid valve 7A is executed by the VTC conversion angle positioning control controller 8A. Detection values of the sensors such as the camshaft position sensor 11A, the water temperature sensor 12, and the crank angle sensor 13 are input to the VTC conversion angle positioning controller 8A. The crank angle sensor 13 outputs an angle signal of the crankshaft and outputs a reference crank position signal at the reference rotation position of the crankshaft. The camshaft position sensor 11A outputs a reference cam position signal at the reference rotation position of the camshaft. The water temperature sensor outputs the engine coolant temperature.

  The VTC conversion angle positioning controller 8A determines the current conversion angle of the variable valve mechanism VTCA based on the deviation angle of the reference rotation position between the crankshaft and the camshaft detected by the crank angle sensor 13 and the camshaft position sensor 11A. To detect. Then, the energization amount to the solenoid valve 7A is controlled by the control described later so that the current conversion angle follows the target conversion angle set based on the operating condition of the engine.

  FIG. 2 is a control block diagram of model reference type two-degree-of-freedom control. The feedforward (F / F) compensator B20 is configured by a product of a reference model indicating a desired response characteristic and an inverse system of the controlled object model, thereby realizing a desired response characteristic, and further, feedback (F / F) B) By applying feedback compensation to the difference between the reference response value, which is the output of the reference model, and the actual control amount in the compensation unit B21, disturbance resistance and robust stability are adjusted. According to this, responsiveness and feedback performance (disturbance and robust stability) can be designed independently, so that the stability is increased as much as necessary, and as long as adequate robust stability is maintained, it is resistant to disturbance. It is possible to improve.

  FIG. 3 is an example of the configuration of the F / F compensation unit B21 when a saturated element is included in the control target. As described above, the control target model B32 including the saturation element and the model reference type control unit B31 that controls the output value of the control target model to match the target value with a desired response characteristic are configured. By performing the simulation, it is possible to calculate the reference response value in consideration of the saturation characteristic and the F / F manipulated variable for making the actual control amount coincide with it.

  FIG. 4 is a control block diagram for controlling the operation of the variable valve mechanisms VTCA and VTCB. When two variable valve mechanisms VTCA and VTCB are operated by one oil pump 10 as in the configuration shown in FIG. 1, the hydraulic pressure fluctuation caused by one operating affects the other operation. So-called hydraulic interference occurs. Therefore, as shown in FIG. 4, in addition to the VTC conversion angle positioning control controllers 8A and 8B, a saturation limit value calculation controller 40 (saturation determination threshold value calculation means) for measures against hydraulic interference is provided.

The VTC conversion angle positioning control controller 8A is configured by model reference control, and includes an F / F compensation unit B41a that calculates a current command value (F / F term) I _comffA and a conversion angle reference response θ _refA , a current command F / B compensator B42a as feedback compensation calculation means for calculating the value (F / B term) I _{comfbA so} that the actual conversion angle θ _nowA of the variable valve mechanism VTCA follows the target conversion angle θ _comA Take control.

The VTC conversion angle positioning control controller 8B has the same configuration, and performs control so that the actual conversion angle θ _nowB of the variable valve mechanism VTCB follows the target conversion angle θ _comB .

Saturated limit value calculation controller 40, the target conversion angle theta _comA, theta VTC conversion angle positioning controller 8A from _COMB, asked additional nominal response and 8B, the speed _ω limitedA, ω limitedB calculates the in are saturated for speed calculation Part B43, limit value setting part B44 for calculating the limit value of the saturation element and giving it to the VTC conversion angle positioning control controllers 8A and 8B, and saturation value calculation part B45 for giving the saturation element based on the engine rotation and oil temperature Consists of dots. Saturation limit values ωd _limHB and ωd _{limLB, which} will be described later, calculated from the target conversion angle θ _comA by the limit value setting unit B44 are given to the VTC conversion angle positioning controller 8B, and calculated from the target conversion angle θ _{comB by the} limit value setting unit B44. The saturation limit values ωd _limHA and ωd _limLA described later are given to the VTC conversion angle positioning control controller 8A.

  FIG. 5 is a flowchart showing specific control by the configuration shown in FIG.

In step S1, the actual conversion angle θ _nowA is calculated based on the detection values of the crank angle sensor 13 and the camshaft position sensor 11A.

In step S2, a target conversion angle θ _comA of the VTC conversion angle positioning control controller 8A is calculated. Specifically, the relationship between the parameter representing the operating state such as the engine speed and the water temperature and the target conversion angle θ _comA is mapped, and the map is searched based on the engine speed at the time of calculation.

In steps S3 and S4, the actual conversion angle θ _nowB and the target conversion angle θ _comB of the VTC conversion angle positioning controller 8B are calculated by the same method as in steps S1 and S2.

  In step S5, the upper limit value and lower limit value of the saturation element are estimated based on the engine speed and the water temperature. For this estimation, a three-dimensional map is used in which the engine speed and the water temperature are input and the value of the saturation element of the conversion angular velocity is output. FIG. 6 is an example of a three-dimensional map for estimating the upper limit value of the saturation element. The lower limit value is estimated using the same map. These maps are set in advance through experiments.

  The upper limit value and lower limit value to be estimated are estimated separately because the variable valve mechanism VTCA and the variable valve mechanism VTCB have different characteristics. In addition, the estimation is performed separately for the case of the strongest hydraulic interference and the case of no hydraulic interference. That is, a total of eight types of upper and lower limit values are estimated as shown in FIG.

In step S6, the reference response speed ω _limtedA for saturation of the variable valve mechanism VTCA is calculated. In step S7, the limit values ωd _limHB and ωd _limLB for the VTC conversion angle positioning controller B are calculated. This will be described with reference to the control block diagram of FIG. FIG. 8 is a diagram showing in detail the configuration of saturation speed calculation unit B43 and limit value setting unit B44 in the control block diagram of FIG.

In step S6, first, the model G _MMA (s) of the variable valve mechanism VTCA to be controlled, G _P1A (s) representing the linear characteristic from the current to the conversion angular velocity, the saturation element A ′, and the position from the velocity. The calculation is performed from the saturation speed calculation unit constituted by G _P2A (s) representing the linear characteristics up to and including.

The transmission formulas of G _P1A (s) and G _P2A (s) are expressed by the following formulas (1) and (2). Here, s is a Laplace operator, K _PA is a gain from a current to a conversion angular velocity, and T _1A is a time constant.

飽和要素Ａ’は、可変動弁機構ＶＴＣＡ、ＶＴＣＢの変換角速度のリミッタである。具体的には、速度のリミット値として、ステップＳ５で算出した値のうち油圧干渉を受けていない場合の上限値ω_limHAMAX、下限値ω_limLAMAXを用い、次のように処理する。

The saturation element A ′ is a limiter for the conversion angular velocity of the variable valve mechanisms VTCA and VTCB. Specifically, as the limit value of the speed, the upper limit omega _LimHAMAX if not receiving hydraulic interference among the calculated values, the lower limit omega _LimLAMAX used in step S5, the processing as follows.

モデルマッチング型制御部Ｇ_MMA（ｓ）は、目標変換角から制御対象モデルの出力である変換角規範応答θ_refA（ｓ）までの線形特性が、所望の応答特性である連続系規範モデル伝達関数Ｇ_refA（ｓ）となるように設計する。連続系規範モデル伝達特性Ｇ_refA（ｓ）を式（３）に示すように２次振動系で設定する。ここで、ω_nは線形規範モデルの固有振動数、ξは減衰率である。

The model matching control unit G _MMA (s) is a continuous reference model transfer function in which the linear characteristic from the target conversion angle to the conversion angle reference response θ _refA (s) that is the output of the controlled object model is a desired response characteristic. Design to be G _refA (s). The continuous system reference model transfer characteristic G _refA (s) is set in the secondary vibration system as shown in Expression (3). Here, ω _n is the natural frequency of the linear reference model, and ξ is the damping rate.

モデルマッチング型制御部Ｇ_MMA（ｓ）は式（４）で表わされる。

The model matching type control unit G _MMA (s) is expressed by Expression (4).

この構成の内部変数である飽和要素Ａ’の出力ω_limitedAが油圧干渉を受けていない状態の可変動弁機構ＶＴＣＡが本来要求する速度となり、制限値設定部Ｂ４４に引き継がれる。

The output ω _limitedA of the saturation element A ′, which is an internal variable of this configuration, becomes the speed originally required by the variable valve mechanism VTCA in a state where it is not subjected to hydraulic interference, and is taken over by the limit value setting unit B44.

In step S7, the limit value setting unit B44 calculates the limit value of the saturation element of the VTC conversion angle positioning control controller 8B for the variable valve mechanism VTCB. As shown in FIG. 8, the limit value setting unit B44 includes an upper limit value map A and a lower limit value map A. From the upper limit value map A, the input is ω _{limitedA and} the upper limit value ωd _limHB of the saturation element is estimated. Similarly, the lower limit limit value ωd _limLB of the saturation element is estimated from the lower limit value map A.

FIG. 9 is an upper limit value map A, where the x-axis is the speed ω _limitedA and the y-axis is ωd _limHB that is the upper limit value of the saturation element of the VTC conversion angle positioning control controller B. The upper limit value ωd _limHB decreases the speed every time the speed ω _limitedA increases up to the speed X1, and limits it to a constant value above the speed X1. By doing this, the minimum speed can be secured even when both VTC conversion angle positioning control controllers VTCA and VTC request the maximum speed.

Ω _limitedA calculated in step S6 above is the speed of the normative response originally required by the VTC conversion angle positioning controller 8A, and the limit value setting unit B44 uses this to cause interference with the other variable valve mechanism VTCB. The reduction of the saturation element is estimated, and the limit value of the saturation element of the VTC conversion angle positioning control controller 8B is set.

In steps S8 and S9, the speed ω _limitedB of the saturation speed calculation unit is obtained by the same method as in steps S6 and S7 using the variable valve mechanism VTCB as a control target model, and the saturation element limit value ωd of the VTC conversion angle positioning control controller A is obtained. _limHA and ωd _limLA are calculated. Thereby, the speed limit value in consideration of the mutual hydraulic interference can be calculated.

  In step S10, the calculation of the F / F compensation unit B41a of the VTC conversion angle positioning controller A is performed.

FIG. 10 is a control block diagram of the F / F compensator B41a. As shown, G _P1A (s), G _P2A (s), which are models of the variable valve mechanism VTCA to be controlled, and a model matching compensator G _MMA (s), and the upper limit value ωd _limHA and the lower limit value ωd _limLA are saturated elements A that are sequentially changed by the limit value setting unit B44. As a result, the normative response θ _refA and the F / F current command value I _comffA are output in consideration of the speed saturation affected by the hydraulic interference. Thereby, since the normative response becomes a response that is almost the same as the actual conversion angle, the deviation is reduced and the overshoot can be reduced.

In step S11, the calculation of the F / B compensator B42a of the VTC conversion angle positioning controller A, that is, the calculation of the current command value (F / B term) I _comfbA is performed.

FIG. 11 is a control block diagram of the F / B compensator B42a, which is configured by PID control as shown. The actual conversion angle θ _nowA calculated in step S1 and the conversion angle reference response θ calculated in step S10. _A current command value (F / B term) I _comfbA is obtained by performing a PID control operation on the deviation from _refA .

For the PID control integrator B53, the speed measurement unit B50 calculates the speed ω _FBA from the actual conversion angle θ _nowA , and the saturation determination unit B51 uses this to calculate the speed saturation upper limit value ωd _limHA and the lower limit value ωd _limLA. Is used as a determination value to determine whether to stop the integrator B53. The integration stop determination in the saturation determination unit B51 is performed as follows.

なお、速度ω_FBAは近似微分にて計測する。

The speed ω _FBA is measured by approximate differentiation.

  By the way, in the control system of the variable valve mechanism VTCA, the input to be controlled is a current (or a voltage duty ratio corresponding thereto), and the output is the conversion angle of the variable valve mechanism VTCA. The object to be controlled can be modeled by a linear characteristic composed of gain, first-order lag, and integration, and a linear characteristic of input saturation of a current value corresponding to speed saturation. The speed saturation value, which is a saturation element to be controlled, is determined by the engine operating state such as the engine speed and the temperature change of the engine oil as a power source, and a plurality of variable valve mechanisms VTCA with the same hydraulic source as shown in FIG. When the VTCB is operated, it also changes due to hydraulic interference caused by the operation of the other.

  The physical saturation value of the current that is the manipulated variable, that is, the value obtained by dividing the power supply voltage applied to the solenoid valve 7A by the total resistance of the system is a value that is not causally related to the speed saturation. Since it occurs at a value lower than the physical current saturation value, determination using the physical current saturation value cannot be performed.

  On the other hand, when the speed saturation value is estimated based on the current that is the manipulated variable and the saturation determination is performed based on the speed, there is a delay from when the solenoid valve 7A is energized until the conversion angular velocity is generated, depending on the dynamic characteristics of the controlled object. Therefore, if the saturation determination is performed after actually reaching the speed saturation, there is a possibility that an excessive current may occur. When the current is excessive, there arises a problem that unintentional overshoot or the like occurs and the performance is deteriorated.

  Therefore, in the present embodiment, considering the fact that the saturation factor of the own system fluctuates according to the control amount of the other system as described above, the saturation determination that receives interference from the estimated speed of the control value of the target value of the other system. The threshold value is determined. As a result, the integrator can be stopped accurately, so that it is possible to prevent unnecessary integration of integration, and the amount of overshoot can be reduced.

In step S12, the sum of the current command value (F / F term) I _{comffA of} the VTC conversion angle positioning controller A and the current command value (F / B term) I _comfbA is _obtained as a current command value I for the VTC conversion angle positioning controller A. _comA is output to the solenoid valve 7A. Actually, a PWM duty ratio is calculated in consideration of the drive voltage and the resistance value of the solenoid valve 7A so as to realize the drive current, and the solenoid valve 7A is PWM driven.

In steps S13 to S15, the F / F compensation unit B41b, the F / B compensation unit B42b, and the current command value I _comB of the VTC conversion angle positioning controller B are calculated by the same method as in steps S10 to _S12 .

  FIG. 12 is a time chart for explaining the effects of the present embodiment. The x-axis is time, the y-axis is the conversion angle θ, the upper part in the figure is a chart for the variable valve mechanism VTCA, and the lower part is a chart for the variable valve mechanism VTCB. In addition, solid lines P, Q, R, and S, broken lines P ′, Q ′, R ′, and S ′ in FIG. 12 indicate conversion angle command values, reference responses, and hydraulic interference speeds of the variable valve mechanisms VTCA and VTCB, respectively. This is the normative response and actual conversion angle when it is affected. Here, it is assumed that the variable valve mechanism VTCA starts to operate first at t1, and then the variable valve mechanism VTCB starts to operate at t2.

  FIG. 13 is a time chart showing the control command value and the control target output when the change in saturation speed due to hydraulic interference is not considered in the same configuration as FIG.

  In FIG. 12, the conversion angle command value A is given to the variable valve mechanism VTCA at t1, the normative response A is determined, and the actual conversion angle A starts to change. Thereafter, at t2, when the conversion angle command value B is given to the variable valve mechanism VTCB, the reference response B is determined, and the actual conversion angle B starts to change, hydraulic interference occurs. Here, if hydraulic interference is not taken into consideration, the control target output will overshoot as shown in FIG.

  However, by calculating the normative responses A and B in which the speed saturation limit value is given in consideration of the hydraulic interference, the stop time of the integrator B53 can be given accurately, so overshooting occurs as shown in FIG. Can be limited. Further, the inclination of the normative response is reduced, and the response can be made almost the same as the actual conversion angle.

As described above, according to the present embodiment, the following effects can be obtained.
(1) A plurality of variable valve mechanisms VTCA, VTCB having a saturation element, one oil pump 10 for driving them, and conversion angles of the plurality of variable valve mechanisms VTCA, VTCB are matched to different target values. In a control device including a plurality of control systems for performing the control, a feedback compensator B42 of each control system that includes at least an integrator B53 and calculates a feedback compensation output based on a deviation between an actual conversion angle and a target value; A saturation limit value calculation controller 40 that estimates a conversion angular velocity from a target value of the system and determines a saturation limit value of the own system based on the estimated conversion angular velocity, and the feedback compensator B42 is based on the saturation limit value. Therefore, it is determined whether or not the conversion angular velocity of the own system is saturated, and when the saturation occurs, the integrator B53 is stopped. The can stop accurately integrator B53 when caused, thereby it is possible to suppress the overshoot.

  (2) The saturation limit value calculation controller 40 performs model reference type control in which the conversion angle of its own system matches the target value with a desired response characteristic, and further calculates a reference response to the target value for the other system. Since the saturation limit value is calculated on the basis of the speed, it is possible to more accurately estimate the conversion angular velocity with respect to the target value of the other system, and thereby the influence due to hydraulic interference can be further suppressed.

  (3) Since the saturation limit value calculation controller 40 uses the saturation element to be controlled as the calculation element in calculating the normative response to the target value of the other system, when calculating the norm response, the output conversion angular velocity can be more accurately determined. Can be estimated.

  (4) When the estimated value of the conversion angular velocity of the other system increases, the saturation limit value calculation controller 40 decreases the saturation limit value of its own system, so when one speed increases, the other is saturated due to the influence of hydraulic interference. The saturation limit value can be determined according to the characteristic that the element is lowered, and the integrator B53 can be stopped at a more accurate timing.

  (5) Since the saturation limit value calculation controller 40 limits the saturation limit value of its own system when the conversion angular velocity of the other system becomes equal to or greater than a predetermined value, the other system requests a conversion angular speed of a certain value or more. In this case, a minimum saturation limit value can be ensured, and both systems can follow the target value while receiving hydraulic interference.

  (6) Each control system has a controlled object model having a saturation element inside, and calculates a normative response and a feedforward manipulated variable according to a saturation determination threshold value of a conversion angular velocity, so that an F / F compensation unit is provided. Using the saturation limit value, it is possible to calculate a standard response that can be output and a current command value (F / F term). For this reason, the deviation from the controlled object can be reduced, and overshoot can be suppressed.

  In the embodiment described above, the variable valve mechanisms VTCA and VTCB have been described as being arranged on the intake side and the exhaust side, respectively. However, in addition to this, a plurality of hydraulic actuators that are operated at different timings can be used with the same hydraulic source. The same applies to any configuration that drives.

  The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made within the scope of the technical idea described in the claims.

It is a system block diagram of a variable valve mechanism. It is a control block diagram of model reference | standard 2 degree-of-freedom control. It is a figure which shows an example of the feedforward compensation part which has a saturation element. It is a control block diagram of a VTC conversion angle positioning control controller. It is a flowchart which shows the control routine of a variable valve mechanism. It is an upper limit map of the conversion angular velocity of a variable valve mechanism. It is a table of the upper limit value and lower limit value of a saturation element. It is a figure which shows the structure of a saturation limit value calculation controller. It is an upper limit map. It is a figure which shows the structure of a feedforward compensator. It is a figure which shows the structure of a feedback compensator. It is a time chart for demonstrating an effect. It is a time chart when not considering hydraulic interference.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camshaft drive sprocket 2 Camshaft 3 Housing 4 Vane 5 Advance angle chamber 6 Delay angle chamber 7 Solenoid valve 8 VTC conversion angle positioning control controller 9 Oil pan 10 Oil pump 11 Camshaft position sensor 12 Water temperature sensor 13 Crank angle sensor

Claims (7)

A plurality of hydraulic actuators having saturated elements;
One hydraulic source for driving the plurality of hydraulic actuators;
A plurality of control systems for matching the control amounts of the plurality of actuators to different target values;
In a hydraulic actuator control device comprising:
Feedback compensation calculation means provided for each control system including at least an integrator and calculating a feedback compensation output based on a deviation between an actual control amount and a target value;
Saturation determination threshold value calculating means for estimating the speed of the control amount from the target value of the other system and determining the saturation determination threshold value of the own system based on this estimated speed;
Have
The feedback compensation calculation means determines whether or not the speed of the control target of the own system is saturated based on the saturation determination threshold, and if the speed of the control target of the own system is saturated, the integration The hydraulic actuator control device is characterized in that the device is stopped. The saturation determination threshold value calculation means performs model reference type control in which the control amount of the own system matches the target value with the continuous reference model transfer characteristic set in the secondary vibration system, and further, the reference response to the target value for the other system The hydraulic actuator control device according to claim 1, wherein the saturation determination threshold value is calculated based on a speed of the normative response.   The hydraulic actuator control device according to claim 2, wherein the saturation determination threshold value calculation unit uses a saturation element to be controlled as a calculation element in calculating a normative response to the target value of the other system.   4. The saturation determination threshold value calculation unit decreases the saturation determination threshold value of the own system when the estimated speed value of the control amount of the other system increases. 5. Hydraulic actuator control device.   The saturation determination threshold value calculation means limits the saturation determination threshold value of the own system when the speed of the control amount of the other system becomes a predetermined value or more. The control device of the hydraulic actuator described in 1.   Each of the control systems includes a controlled object model having a saturation element, and calculates a reference response and a feedforward manipulated variable according to a saturation determination threshold value of the speed of the controlled variable. The hydraulic actuator control device according to any one of 5. A plurality of hydraulic actuators having saturated elements;
One hydraulic source for driving the plurality of hydraulic actuators;
With
In the control method of the hydraulic actuator for matching the control amounts of the plurality of actuators with different target values,
The speed of the control amount is estimated from the target value of the other system, and it is determined whether or not the control target of the own system is saturated based on the saturation determination threshold value of the own system determined based on this speed. When it is determined that the control target of the system is saturated, the operation of the integrator provided in the feedback compensation unit that calculates the feedback compensation output based on the deviation between the actual control amount and the target value is stopped. Control method for hydraulic actuator.

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