JP2005090251A - Control device for solenoid drive valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a solenoid drive valve for properly controlling a state quantity of a valve element to be a target state quantity, by operating a current amount applied to an electromagnet. <P>SOLUTION: In step 440, each control gain is calculated by using displacement x(n) fetched in step 400 and the last command current amount I(n-1). That is, the control gains corresponding to a proportional, an integral item, and a differential item with respect to deviance of the quantity amount of the valve element from the target state quantity are calculated by using the displacement x(n) of the valve element and the last time command current amount I(n-1). In this way, when the calculation of the control gains is completed, in step 450, the command current amount I(n) is calculated by using the calculated control gains, and the series of processing is finished once. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is applied to an electromagnetically driven valve that drives a valve body by electromagnetic force generated by an electromagnet, and performs electromagnetic feedback control that controls the state quantity of the valve body to a target state quantity by operating an amount of current applied to the electromagnet. The present invention relates to a valve control device.

As this type of electromagnetically driven valve control device, for example, as shown in Patent Document 1 below, an apparatus that performs feedback control so that the actual drive speed of the valve body matches the target drive speed has been proposed. . Here, the electromagnetic force for driving the valve body changes according to the displacement of the valve body. For this reason, in the said control apparatus, the control gain used for the said feedback control is variably set according to the displacement of a valve body. As described above, by variably setting the control gain according to the displacement of the valve body, it is possible to improve responsiveness and stability with respect to feedback control.
Japanese Patent Laid-Open No. 2002-81329

  By the way, the change in the electromagnetic force with respect to the change in the amount of current applied to the electromagnet is not determined only by the amount of change in the current applied to the electromagnet, but depends on the amount of current that is the starting point of the change. Therefore, even if the control gain is variably set according to the displacement of the valve body, there is a problem that the change in the electromagnetic force relative to the change in the amount of current applied to the electromagnet is not necessarily appropriate for stable feedback control. It was.

  In addition to the control device described in Patent Document 1, the control device that feedback-controls the state quantity of the valve body to the target state quantity by manipulating the amount of current applied to the electromagnet. These facts, which are difficult to do, are generally common.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electromagnetic drive capable of appropriately controlling a state quantity of a valve body by a target state quantity by operating an amount of current applied to an electromagnet. The object is to provide a valve control device.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is applied to an electromagnetically driven valve that drives a valve body by electromagnetic force generated by an electromagnet, and the state quantity of the valve body is fed back to a target state quantity by operating an amount of current applied to the electromagnet. The gist of the control device for the electromagnetically driven valve to be controlled is to change the feedback control mode based on the amount of current applied to the electromagnet.

  In the above configuration, the feedback control mode is changed based on the amount of current applied to the electromagnet. Therefore, considering that the change in the electromagnetic force that drives the valve element with respect to the change in the amount of current applied to the electromagnet depends on the amount of current applied to the electromagnet, it is appropriate for each amount of current applied to the electromagnet. Feedback control can be performed. Therefore, according to the said structure, the state quantity of a valve body can be appropriately controlled now by the target state quantity by operating the electric current amount given to an electromagnet.

  According to a second aspect of the present invention, in the first aspect of the invention, the change in the feedback control mode is that the change in the electromagnetic force relative to the change in current from the amount of current applied to the electromagnet is substantially linear. The gist is that the calculation is performed by calculating the amount of current applied to the electromagnet based on a physical model approximated as a change.

  According to the physical model, it is possible to appropriately grasp the change in electromagnetic force with respect to the change in current from the amount of current applied to the electromagnet. Therefore, according to the above configuration, by calculating the amount of current applied to the electromagnet based on the physical model, it is possible to appropriately grasp the change in electromagnetic force relative to the change in current from the amount of current applied to the electromagnet. However, the feedback control can be performed.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the change of the feedback control mode is performed as a variable setting of the control gain based on the amount of current applied to the electromagnet. The gist.

  In the above configuration, the control gain is variably set based on the amount of current applied to the electromagnet. Therefore, considering that the change in the electromagnetic force that drives the valve element with respect to the change in the amount of current applied to the electromagnet depends on the amount of current applied to the electromagnet, it is appropriate for each amount of current applied to the electromagnet. It is possible to set the control gain.

  The invention according to claim 4 is applied to an electromagnetically driven valve that drives a valve body by electromagnetic force generated by an electromagnet, and the state quantity of the valve body is fed back to a target state quantity by operating an amount of current applied to the electromagnet. In a control device for an electromagnetically driven valve to be controlled, based on a current amount necessary for generating an electromagnetic force preliminarily assumed to be necessary for setting the state quantity of the valve body as the target state quantity. The gist is to change the mode of the feedback control.

  When feedback control is performed on the state quantity of the valve body to the target state quantity, each time it is necessary to generate the electromagnetic force that is assumed to be necessary to make the state quantity of the valve body the target state quantity. Is generally approximate to the actual amount of current applied to the electromagnet. And the change of the electromagnetic force with respect to the change of the current from the actual amount of current applied to the electromagnet depends not only on the amount of change of the current but also on the actual amount of current.

  Here, in the said structure, the aspect of feedback control is changed based on the electric current amount each time required in order to generate | occur | produce the said electromagnetic force assumed beforehand. Therefore, appropriate feedback control should be performed at each control timing in consideration of the fact that the change in electromagnetic force that drives the valve element with respect to the change in the amount of current applied to the electromagnet depends on the amount of current applied to the electromagnet. Will be able to. Therefore, according to the said structure, the state quantity of a valve body can be appropriately controlled now by the target state quantity by operating the electric current amount given to an electromagnet.

  According to a fifth aspect of the present invention, in the fourth aspect of the invention, the change of the feedback control mode is the change of the electromagnetic force with respect to the change of the current from the current amount required for generating the electromagnetic force. The gist of this is to calculate the amount of current applied to the electromagnet based on a physical model approximated as a substantially linear change.

  When feedback control is performed on the state quantity of the valve body to the target state quantity, each time it is necessary to generate the electromagnetic force that is assumed to be necessary to make the state quantity of the valve body the target state quantity. Is generally approximate to the actual amount of current applied to the electromagnet. For this reason, the change of the electromagnetic force with respect to the change in current from the required amount of current approximates the change of electromagnetic force with respect to the change in current from the amount of current applied to the electromagnet.

  For this reason, according to the said physical model, it becomes possible to grasp | ascertain appropriately the change of the electromagnetic force with respect to the change of the electric current from the electric current amount given to the electromagnet. For this reason, according to the above configuration, the feedback control is performed while appropriately grasping the change in electromagnetic force with respect to the change in current at each control timing by calculating the amount of current applied to the electromagnet based on the physical model. Will be able to.

  According to a sixth aspect of the present invention, in the invention of the fourth or fifth aspect, the change of the feedback control mode is performed as a variable setting of a control gain based on a current amount necessary for generating the electromagnetic force. The gist of this is

  When feedback control is performed on the state quantity of the valve body to the target state quantity, each time it is necessary to generate the electromagnetic force that is assumed to be necessary to make the state quantity of the valve body the target state quantity. Is generally approximate to the actual amount of current applied to the electromagnet.

  Here, in the above configuration, the control gain is variably set based on the amount of current required for generating the electromagnetic force. For this reason, considering that the change in the electromagnetic force used to drive the valve element in response to the change in the amount of current applied to the electromagnet depends on the amount of current applied to the electromagnet, an appropriate control gain at each control timing Can be set.

  The invention according to claim 7 is applied to an electromagnetically driven valve that drives a valve body by electromagnetic force generated by an electromagnet, and the state quantity of the valve body is fed back to a target state quantity by operating an amount of current applied to the electromagnet. The gist of the control device for the electromagnetically driven valve to be controlled is to consider the nonlinearity of the change in the electromagnetic force with respect to the change in the current amount when the current amount is operated.

  When the change of the electromagnetic force with respect to the change of the current amount applied to the electromagnet has non-linearity, the change of the electromagnetic force with respect to the change of the current is not uniquely determined. For this reason, the change in the electromagnetic force when the current amount is changed so as to feedback control the valve state amount to the target state amount is not uniquely determined, and the amount of change in the current amount is an appropriate amount for the feedback control. It may not be.

  In this regard, in the above configuration, when the current amount is manipulated, feedback control can be performed with an appropriate current amount by taking into consideration the nonlinearity of the change in electromagnetic force with respect to the change in current amount. Therefore, according to the said structure, the state quantity of a valve body can be appropriately controlled now by the target state quantity by operating the electric current amount given to an electromagnet.

  The invention according to claim 8 is applied to an electromagnetically driven valve that drives a valve body by electromagnetic force generated by an electromagnet, and by operating the amount of current applied to the electromagnet, the state quantity of the valve body is changed to a target feedback state quantity. The gist of the control device of the electromagnetically driven valve to be controlled is to manipulate the current amount based on a physical model in which the change in the electromagnetic force with respect to the change in the arbitrary current amount is approximated as a substantially linear change.

  According to the physical model, it is possible to appropriately grasp a change in electromagnetic force with respect to a change in current from an arbitrary amount of current. Therefore, according to the above configuration, by calculating the amount of current applied to the electromagnet based on the physical model, the feedback control is performed while appropriately grasping the change in electromagnetic force with respect to the change in current from an arbitrary amount of current. Will be able to do.

  The invention according to claim 9 is applied to an electromagnetically driven valve that drives a valve body by electromagnetic force of an electromagnet, and the state quantity of the valve body is fed back to a target state quantity by operating an amount of current applied to the electromagnet. The gist of the control device for the electromagnetically driven valve to be controlled is to set a control gain when calculating the current amount in consideration of nonlinearity of the change in the electromagnetic force with respect to the change in the current amount.

  When the change of the electromagnetic force with respect to the change of the current amount applied to the electromagnet has non-linearity, the change of the electromagnetic force with respect to the change of the current is not uniquely determined. For this reason, the control gain for calculating the amount of current when performing feedback control of the state quantity of the valve body to the target state quantity may not be an appropriate quantity for feedback control.

  In this regard, in the above configuration, feedback control can be performed with an appropriate control gain by taking into consideration the nonlinearity of the change in electromagnetic force with respect to the change in current amount when setting the control gain. Therefore, according to the said structure, the state quantity of a valve body can be appropriately controlled now by the target state quantity by operating the electric current amount given to an electromagnet.

(First embodiment)
Hereinafter, a first embodiment in which an electromagnetically driven valve control device according to the present invention is applied to a control device that opens and closes a valve body that functions as an intake valve or an exhaust valve of an internal combustion engine will be described.

  In the present embodiment, both the intake valve and the exhaust valve are configured as electromagnetically driven valves that are opened and closed based on the electromagnetic force of the electromagnet. Since these intake valves and exhaust valves have the same configuration and drive control mode, the exhaust valves will be described below as an example.

  As shown in FIG. 1, the exhaust valve 10 of the present embodiment includes the following. That is, a valve shaft 20 supported so as to be able to reciprocate in the cylinder head 18, an armature shaft 26 coaxially disposed with the valve shaft 20 and reciprocating with the valve shaft 20, and provided at one end of the valve shaft 20. A valve body 19 constituted by the umbrella portion 16 provided, and an electromagnetic drive section 21 for reciprocatingly driving the valve body 19 are provided.

  An exhaust port 14 that communicates with the combustion chamber 12 is formed in the cylinder head 18, and a valve seat 15 is formed around the opening periphery of the exhaust port 14. As the valve shaft 20 reciprocates, the exhaust port 14 is opened and closed when the umbrella portion 16 is separated from and seated with the valve seat 15.

  In the valve shaft 20, a lower retainer 22 is fixed to the end opposite to the end where the umbrella portion 16 is provided. A lower spring 24 is disposed in a compressed state between the lower retainer 22 and the cylinder head 18. The valve element 19 is biased in the valve closing direction (upward in FIG. 1) by the elastic force of the lower spring 24.

  A disk-shaped armature 28 made of a high magnetic permeability material is fixed to a substantially central portion in the axial direction of the armature shaft 26, and an applicator 30 is fixed to one end of the armature shaft 26. The end of the armature shaft 26 opposite to the end to which the applicator 30 is fixed contacts the end of the valve shaft 20 on the lower retainer 22 side.

  In the casing (not shown) of the electromagnetic drive unit 21, an upper core 32 is positioned and fixed between the upper retainer 30 and the armature 28. Similarly, in the casing, a lower core 34 is fixed between the armature 28 and the lower retainer 22. Each of the upper core 32 and the lower core 34 is formed in an annular shape from a high magnetic permeability material, and an armature shaft 26 is inserted in a central portion thereof so as to be able to reciprocate.

  An upper spring 38 is disposed in a compressed state between the upper cap 36 and the upper retainer 30 provided in the casing. The valve element 19 is biased in the valve opening direction (downward in FIG. 1) by the elastic force of the upper spring 38.

  A displacement amount sensor 52 is attached to the upper cap 36. The displacement sensor 52 outputs a voltage signal that changes in accordance with the distance between the displacement sensor 52 and the applicator 30. Therefore, the displacement amount of the armature shaft 26 and the valve shaft 20 can be detected based on this voltage signal.

  An annular groove 40 centering on the axis of the armature shaft 26 is formed on a surface of the upper core 32 facing the armature 28, and an annular upper coil 42 is disposed in the groove 40. The upper coil 42 and the upper core 32 constitute a closing drive electromagnet 61 that is an electromagnet for driving the valve element 19 in the valve closing direction.

  On the other hand, an annular groove 44 centering on the axis of the armature shaft 26 is formed on the surface of the lower core 34 facing the armature 28, and an annular lower coil 46 is disposed in the groove 44. The lower coil 46 and the lower core 34 constitute an open driving electromagnet 62 which is an electromagnet for driving the valve element 19 in the valve opening direction.

  The coils (the lower coil 46 and the upper coil 42) of the close drive electromagnet 61 and the open drive electromagnet 62 are energized and controlled by an ECU (electronic control unit) 50 that performs various controls of the internal combustion engine. The ECU 50 includes a central processing unit and a memory, an input circuit for receiving a detection signal of the displacement sensor 52, an A / D converter (all not shown) for A / D converting the detection signal, and the like. Has been.

  In FIG. 1, the valve element 19 is shown when no current is supplied to either the closed drive electromagnet 61 or the open drive electromagnet 62, and no electromagnetic force is generated in the closed drive electromagnet 61 and the open drive electromagnet 62. Shows the state. In this state, the armature 28 is not attracted by the electromagnetic force of the closing drive electromagnet 61 and the opening drive electromagnet 62, and the urging force of the lower spring 24 and the upper spring 38 is balanced between the upper core 32 and the lower core 34. It stops at an intermediate position. Further, in this state, the umbrella portion 16 is separated from the valve seat 15 and the exhaust valve 10 is in a half-open state. Hereinafter, the position of the valve body 19 in this state is referred to as a neutral position.

Next, an operation mode of the exhaust valve 10 that is driven to open and close through energization control with respect to the closing driving electromagnet 61 and the opening driving electromagnet 62 will be described.
First, when the exhaust valve 10 is held in the fully closed state, a holding current for holding the exhaust valve 10 in the fully closed state is supplied to the closing drive electromagnet 61. By supplying this holding current, the armature 28 is attracted by the electromagnetic force of the closing drive electromagnet 61 and is held in contact with the upper core 32 against the elastic force of the upper spring 38, and the umbrella portion 16 is valved. The state of being seated on the seat 15 is maintained.

  Next, when the opening drive timing of the exhaust valve 10 comes, the supply of the holding current is interrupted. As a result, the exhaust valve 10 is opened by the elastic force of the upper spring 38. In other words, the armature 28 moves toward the opening drive electromagnet 62, so that the valve body 19 moves away from the valve seat 15 and moves toward the combustion chamber 12.

  Then, in the process of displacing the valve body 19 from the fully closed position to the fully opened position, energization control of the open driving electromagnet 62 is performed. During this period, the electromagnetic force that attracts the valve body 19 in the valve opening direction is controlled through the adjustment of the attraction current to the opening driving electromagnet 62 so that the valve body 19 reliably reaches the fully opened position with a predetermined displacement speed.

  When the valve body 19 reaches the fully open position, a holding current for holding the exhaust valve 10 in the fully open state is supplied to the open driving electromagnet 62 until a predetermined period elapses from that time. By supplying this holding current, the armature 28 is attracted by the electromagnetic force of the open driving electromagnet 62 and is held in contact with the lower core 34 against the elastic force of the lower spring 24, and the umbrella portion 16 is valved. The state most distant from the seat 15 is held.

  Next, when a predetermined period elapses after the valve element 19 reaches the fully open position, the supply of the holding current for holding the exhaust valve 10 at the fully open position is interrupted. Thereby, the exhaust valve 10 is displaced toward the valve closing direction by the elastic force of the lower spring 24, in other words, the valve body 19 is displaced toward the valve seat 15.

  Then, in the process of displacement of the exhaust valve 10 from the fully open position to the fully closed position, energization control is performed on the electromagnet 61 for driving for closing. During this period, the electromagnetic force that attracts the valve body 19 in the valve closing direction is controlled through the adjustment of the suction current to the electromagnet 61 for driving the closing so that the valve body 19 reliably reaches the fully closed position with a predetermined displacement speed. .

  When the valve body 19 reaches the fully closed position, a holding current for holding the exhaust valve 10 in the fully closed state is supplied to the closing drive electromagnet 61 from that time until the next opening drive timing comes. Will be supplied again.

  In the operation of the exhaust valve 10 of the above aspect, in the present embodiment, the valve body 19 (specifically, the valve body 19 and the armature 28 are moved by operating the amount of current applied to the closing drive electromagnet 61 and the opening drive electromagnet 62. The state quantity of the movable part provided) is feedback controlled to the target state quantity. Specifically, in the present embodiment, the feedback control is performed by sliding mode control. This will be described in detail below.

  In the present embodiment, the exhaust valve 10 is connected to the elastic force of the lower spring 24 and the upper spring 38, the sliding resistance between the movable part and the fixed part, the electromagnetic force acting on the armature 28, and the external force such as the in-cylinder pressure. Is a system applied to the movable part. In addition to the weight M of the movable part, the spring constant K, and the displacement x of the valve body 19, the equation of motion of this system includes the damping constant C between the movable part and the fixed part, the external force f, and the state quantity of the valve body 19 Is expressed by the following expression (c1) using the electromagnetic force U acting on the armature 28 to follow the target state quantity. Here, the displacement x of the valve body 19 is actually the distance between the armature 28 and the electromagnet 61 for driving and the electromagnet 62 for driving.

ここで、外力ｆをモデル誤差とし、上記バネ定数Ｋに基づく弾性力と上記減衰定数Ｃに基づく摺動抵抗との作用する弁体１９の状態量を、スライディングモード入力ｕｌによって目標とする状態量に制御することを考える。この場合、スライディングモード入力ｕｌによって弁体１９の状態量を目標とする状態量に制御する物理モデルは、下式（ｃ２）となる。

Here, with the external force f as a model error, the state quantity of the valve element 19 on which the elastic force based on the spring constant K and the sliding resistance based on the damping constant C act is set as a target state quantity by the sliding mode input ul. Think about controlling it. In this case, the physical model for controlling the state quantity of the valve element 19 to the target state quantity by the sliding mode input ul is represented by the following expression (c2).

上式（ｃ２）で表記される物理モデルは、行列表記することで下式（ｃ３）と表記される。

The physical model represented by the above equation (c2) is represented by the following equation (c3) by matrix notation.

ここで、上記スライディングモード入力ｕｌを通じて弁体１９の状態量を所望の切換超平面に制御することを考える。この切換超平面は、行列Ｓ＝（ｓ１，１）を用いて定義される下式（ｃ４）を満たす状態量Ｘにて表記される。

Here, it is considered that the state quantity of the valve body 19 is controlled to a desired switching hyperplane through the sliding mode input ul. This switching hyperplane is represented by a state quantity X that satisfies the following expression (c4) defined using the matrix S = (s1, 1).

ただし、上式（ｃ４）において、ｓ１は弁体１９の変位ｘに応じて可変設定されることが望ましい。換言すれば、切換超平面を弁体１９の変位ｘに応じて可変設定することが望ましい。ここで、弁体１９の状態量がスライディングモード状態にあるとすると、下式（ｃ５）が成立する。

However, in the above equation (c4), it is desirable that s1 is variably set according to the displacement x of the valve body 19. In other words, it is desirable to variably set the switching hyperplane according to the displacement x of the valve body 19. Here, if the state quantity of the valve body 19 is in the sliding mode state, the following expression (c5) is established.

上式（ｃ５）より、スライディングモード入力ｕｌは、下式（ｃ６）となる。

From the above equation (c5), the sliding mode input ul is represented by the following equation (c6).

ここで、アーマチャ２８に作用する電磁石（閉駆動用電磁石６１や開駆動用電磁石６２）とアーマチャ２８との間の距離（弁体１９の変位ｘ）、上記電磁石に与えている電流量Ｉに対して、アーマチャ２８に作用する電磁力Ｕは、下式（ｃ７）によって表記される。

Here, with respect to the distance (displacement x of the valve body 19) between the electromagnet (the closed drive electromagnet 61 and the open drive electromagnet 62) acting on the armature 28 and the armature 28, and the current amount I applied to the electromagnet. The electromagnetic force U acting on the armature 28 is expressed by the following expression (c7).

上式（ｃ７）において、係数ｋは、「Ｎ^２・μ０・Ｓ／４」と表記される。ただし、Ｎは、電磁石のコイル（アッパコイル４２又はロアコイル４６）の巻き数であり、μ０は真空の透磁率であり、Ｓは、電磁石（閉駆動用電磁石６１又は開駆動用電磁石６２）の断面積である。また、上式（ｃ７）において、ｘ０は、「Ｌ／２μｓ」と表記される。ここで、Ｌはアーマチャ２８と電磁石（閉駆動用電磁石６１又は開駆動用電磁石６２）とで形成される磁路の長さのうち、アーマチャ２８及び電磁石間のギャップ分を除いたものである。

In the above equation (c7), the coefficient k is expressed as “N ² · μ0 · S / 4”. Where N is the number of turns of the electromagnet coil (upper coil 42 or lower coil 46), μ0 is the vacuum permeability, and S is the cross-sectional area of the electromagnet (closed drive electromagnet 61 or open drive electromagnet 62). It is. In the above formula (c7), x0 is expressed as “L / 2 μs”. Here, L is obtained by removing the gap between the armature 28 and the electromagnet from the length of the magnetic path formed by the armature 28 and the electromagnet (the closed driving electromagnet 61 or the open driving electromagnet 62).

  Here, if the sliding mode input ul represented by the above equation (c6) is generated by the amount of current I given to the electromagnet, the current amount I satisfies the following equation (c8).

ここで、実際の状態量Ｘを、下式（ｃ９）にて表記される目標とする状態量Ｘｍにフィードバック制御することを考える。

Here, it is considered that the actual state quantity X is feedback controlled to the target state quantity Xm expressed by the following equation (c9).

この目標とする状態量Ｘｍは各変位ｘｍ毎にその変位速度が定められたものである。ただし、本実施形態では、スライディングモード制御を行う関係上、この目標とする状態量Ｘｍは、上式（ｃ４）にて定義される切換超平面によって規定されている。

The target state quantity Xm has a displacement speed determined for each displacement xm. However, in the present embodiment, because of the sliding mode control, the target state quantity Xm is defined by the switching hyperplane defined by the above equation (c4).

  On the other hand, in the physical system represented by the above equation (c2), the sliding mode input um that is assumed to be necessary to set the actual state amount X as the target state amount Xm is the following equation (c10). )

上式（ｃ１０）のスライディングモード入力ｕｍは、実際の物理系が上式（ｃ２）にて表記されるなら実際の状態量Ｘを目標とする状態量Ｘｍにスライディングモード制御することのできる入力である。ただし、上式（ｃ２）は、外力ｆを除いていること等に起因して実際の物理系に対してモデル誤差を有するものとなっている。そこで、目標とする状態量Ｘｍに対する実際の状態量Ｘの差を微小な変化量ΔＸとして、上式（ｃ８）を目標とする状態量Ｘｍの近傍で展開することを考える。更に、実際の状態量Ｘを目標とする状態量Ｘｍとするのに必要であると予め想定される電流量Ｉｍに対する実際の電流量Ｉの差を微小な変化量ΔＩとして、上式（ｃ８）を上記想定される電流量Ｉｍの近傍で展開することを考える。上式（ｃ８）を、これら目標とする状態量Ｘｍや想定される電流量Ｉｍを用いて書き直すと下式（ｃ１１）となる。

The sliding mode input um of the above equation (c10) is an input that can control the sliding mode to the target state amount Xm if the actual physical system is expressed by the above equation (c2). is there. However, the above equation (c2) has a model error with respect to the actual physical system due to the removal of the external force f. Therefore, it is considered that the difference of the actual state quantity X with respect to the target state quantity Xm is set as a minute change amount ΔX and the above equation (c8) is developed in the vicinity of the target state quantity Xm. Further, the difference of the actual current amount I with respect to the current amount Im assumed in advance to be necessary to set the actual state amount X as the target state amount Xm is defined as a minute change amount ΔI, and the above equation (c8) Is developed in the vicinity of the assumed current amount Im. When the above equation (c8) is rewritten using the target state quantity Xm and the assumed current amount Im, the following expression (c11) is obtained.

上式（ｃ１１）の中辺を微小変化分の一次の項まで用いてテラー展開すると下式（ｃ１２）となる。

When Teller expansion is performed using the middle side of the above equation (c11) to the first term of the minute change, the following equation (c12) is obtained.

上式（ｃ１１）において、中辺を上式（ｃ１２）にて近似するとともに、上式（ｃ１０）を用いてスライディングモード入力ｕｍにかかる項を消去すると、下式（ｃ１３）となる。

In the above equation (c11), when the middle side is approximated by the above equation (c12) and the term relating to the sliding mode input um is deleted using the above equation (c10), the following equation (c13) is obtained.

上式（１３）は、実際の状態量Ｘが目標とする状態量Ｘｍからずれた場合について、上記変化量ΔＸと電流量の変化量ΔＩとの関係を与えるものである。上式（ｃ１３）は、左辺にある変位の変化量Δｘの項を右辺に移項することによって、下式（ｃ１４）のように表記される。

The above equation (13) gives the relationship between the change amount ΔX and the change amount ΔI of the current amount when the actual state amount X deviates from the target state amount Xm. The above equation (c13) is expressed as the following equation (c14) by moving the displacement change amount Δx on the left side to the right side.

ただし、Ｋｍは、下式（ｃ１５）にて表記される。

However, Km is expressed by the following formula (c15).

上式（ｃ１４）は、予め想定される電流量Ｉｍからの電流の変化量ΔＩに対する電磁力の変化量Δｕが線形な変化として近似される物理モデルとなっている。この物理モデルは、図２に示すように、上式（ｃ７）で示される曲線に対して上記想定される電流量Ｉｍにて接する接線となっている。こうした物理モデルを用いることで、上記想定される電流量Ｉｍからの電流の変化量ΔＩに対する電磁力の変化量Δｕを適切に把握しつつフィードバック制御を行うことが可能となる。

The above equation (c14) is a physical model in which the amount of change Δu of the electromagnetic force with respect to the amount of change ΔI in current from the current amount Im assumed in advance is approximated as a linear change. As shown in FIG. 2, the physical model is a tangent line that is in contact with the curve represented by the above equation (c7) at the assumed current amount Im. By using such a physical model, it is possible to perform feedback control while appropriately grasping the change amount Δu of the electromagnetic force with respect to the change amount ΔI of the current from the assumed current amount Im.

  Here, when the change in electromagnetic force has nonlinearity with respect to the change in current as shown in the above equation (c7), the change amount Δu of the electromagnetic force with respect to the change amount ΔI of the current is not uniquely determined. , Depending on the assumed current amount Im. For this reason, if the current amount I is directly calculated using the above equation (c8) or the like, the amount of change Δu of the electromagnetic force with respect to the amount of change ΔI of the current changes each time depending on the assumed amount of current Im. It is difficult to give an appropriate electromagnetic force for feedback control to the target state quantity. In this regard, by using a linear physical model as in the above equation (c14), feedback control can be performed while appropriately grasping the amount of change in electromagnetic force with respect to each change in current amount.

  Further, in the above equation (c14), the physical system can be regarded as a system having a renormalized spring constant Km by replenishing the coefficient of the displacement change amount Δx for the transferred term to the spring constant K. Is shown. That is, the physical system in which the electromagnetic force change Δu with respect to the current change ΔI is approximated as a linear change is a system having a spring constant that changes depending on the target displacement xm and the current amount Im assumed at this time. Can be considered. Therefore, by using the above equation (c14), it is possible to perform appropriate feedback control while reflecting the change of the physical system whose characteristics change depending on the target displacement xm and the current amount Im assumed in advance. It becomes.

  By using such a change amount Δu of the electromagnetic force, the sliding mode input ul is expressed as um + Δu. Furthermore, in the sliding mode control, since the arrival mode input unl that is an input given when the actual state quantity is separated from the switching hyperplane expressed by the above equation (c4) is added, the following equation (c16) It is written.

上式（ｃ１６）から電磁石に与える電流量を算出することができる。

The amount of current applied to the electromagnet can be calculated from the above equation (c16).

  Here, a processing procedure related to calculation of a command current amount which is an operation amount of energization to the electromagnet by the ECU 50 will be described with reference to FIG. The process of FIG. 3 is a process repeatedly executed by the ECU 50 at a predetermined cycle.

  In this series of processing, first, in step 100, the displacement x (n) of the valve body 19 calculated based on the detection result of the displacement sensor 52 is taken. Here, the displacement x (n) of the valve body 19 is a distance between the electromagnet to be energized and the armature 28. That is, for example, when the armature 28 is attracted by the opening driving electromagnet 62 so as to control the valve body 19 to the valve opening side, the displacement x (n) of the valve body 19 is determined by the opening driving electromagnet 62 and the armature 28. And the distance. For example, when the armature 28 is attracted by the closing drive electromagnet 61 to control the valve body 19 to the valve closing side, the displacement x (n) of the valve body 19 is determined by the closing drive electromagnet 61 and the armature 28. And the distance.

  In the following step 110, the displacement speed of the valve body 19 is calculated. For example, in the series of processes shown in FIG. 3, the displacement speed of the valve body 19 is changed from the displacement x (n) of the valve body 19 at the current processing timing to the displacement x (n−1) of the valve body 19 at the previous processing timing. ) Or a value obtained by dividing this value by the cycle of a series of processes shown in FIG.

  In the following step 120, a target displacement xm (n) of the valve body 19 is calculated. This target displacement 19 of the valve body 19 is a value at the current processing timing of the series of processing shown in FIG. 3 for the target state quantity Xm according to a predetermined standard model. That is, for example, when the exhaust valve 10 is driven to open, the target state quantity Xm is uniquely determined at each time from when the supply of the holding current is stopped until the valve body 19 reaches the fully open position. For this reason, the target state quantity Xm for the time corresponding to the same timing is determined for each processing timing. In step 120, the displacement xm of the valve body 19 in the corresponding state quantity Xm is calculated.

  In step 130, the target displacement speed of the valve body 19 is calculated. This target displacement 19 of the valve body 19 is a value at the current processing timing of the series of processing shown in FIG. 3 for the target state quantity Xm according to a predetermined standard model. However, in this step 130, for example, the displacement speed of the target valve body 19 is calculated from the previous displacement xm (n-1) and the current displacement x (n) for the target displacement of the valve body 19, for example. You may do it. In this case, the method for calculating the displacement speed of the valve body 19 may be the same as that in step 110, for example.

  In the subsequent step 140, the spring that has been retreated by the above equation (c15) using the target displacement xm (n) of the valve body 19 and the current amount Im (n) that is assumed at the processing timing. A constant Km (n) is calculated. Further, in step 150, the amount of change Δu (n) of the electromagnetic force is calculated by the above equation (c14) using the spring constant Km (n) that has been brought in.

  In the subsequent step 160, the command current amount I (n), which is the amount of operation of energizing the electromagnet by the ECU 50, is calculated by the above equation (c16) using the electromagnetic force variation Δu (n) thus obtained. Here, in addition to the electromagnetic force variation Δu (n), the sliding mode input um represented by the above equation (c10) and the value um (n) at the processing timing for the reaching mode input unl. ), Unl (n) are calculated and used.

When the process of step 160 is completed in this way, this series of processes is temporarily ended.
According to the embodiment described above, the following effects can be obtained.
(1) By using a physical model in which the change amount Δu of the electromagnetic force with respect to the change amount ΔI of the current from the assumed current amount Im is approximated as a linear change, the current from the assumed current amount Im The feedback control can be performed while appropriately grasping the change amount Δu of the electromagnetic force with respect to the change amount ΔI.

(Second Embodiment)
Hereinafter, a second embodiment in which the control device for an electromagnetically driven valve according to the present invention is applied to a control device that opens and closes a valve body that functions as an intake valve or an exhaust valve of an internal combustion engine, and the first embodiment described above. The difference will be mainly described.

  In the first embodiment, the retraction spring constant Km (n) is calculated using the current amount Im (n) assumed for each processing timing and the displacement xm (n) of the valve body 19. I made it. On the other hand, in the present embodiment, for each processing timing, the spring constant retreated using the displacement x (n) of the valve body 19 taken in each time and the previous command current amount I (n−1). Km is calculated.

  By calculating the spring constant Km drawn in such a manner, for example, when the external force f in the above equation (c1) is increased, the actual state quantity X is greatly separated from the target state quantity Xm. In addition, a more appropriate command current amount can be calculated. This is due to the following reason.

  That is, in the Teller expansion using the first order term according to the above equation (c12), the difference between the actual displacement x of the valve body 19 and the target displacement xm of the valve body 19 is small, and the estimated current amount An accurate approximation is obtained when the difference between the actual current amount I and Im is small. For this reason, as the external force f is larger and the actual state quantity X is farther away from the target state quantity Xm, the accuracy of approximation of the above equation (12) decreases, and as a result, expressed by the above equation (c14). The accuracy of the input change amount Δu decreases. Further, when the external force f is large, the reaching mode input unl shown in the above equation (c16) becomes large, and the command current amount calculated by the equation (c16) is up to the first order shown in the above equation (c12). It does not guarantee the validity of the Teller deployment. For this reason, the command current amount calculated using the above equation (c16) is expressed by the above equation (c14), which is a physical model in which a change in electromagnetic force with respect to a change in the current amount is approximated as a linear change. The physical model is not properly reflected.

  On the other hand, the spring constant Km that has been retracted is calculated using the displacement x (n) of the valve element 19 that is taken in each time and the previous command current amount I (n−1) at each processing timing. As a result, the physical model represented by the above equation (c14) can reflect the characteristics of the physical system each time more accurately. That is, the physical model represented by the above formula (c14) is a physical model that accurately approximates a change in electromagnetic force with respect to a change in current from a current amount applied to the electromagnet as a linear change. Can do.

  Here, a processing procedure for calculating the command current amount in the present embodiment will be described with reference to FIG. The process of FIG. 4 is a process repeatedly executed by the ECU 50 at a predetermined cycle.

  In this series of processing, in steps 200 to 230, processing similar to that in steps 100 to 130 in FIG. 3 is performed. In step 240, the spring constant Km (n) is calculated using the displacement x (n) of the valve element 19 taken in in step 200 and the previous command current amount I (n-1). To do. Here, in the above equation (c15), the spring constant Km (n) that has been brought forward by setting the displacement xm as the displacement x (n) and the current amount Im as the previous command current amount I (n−1) is obtained. calculate. Further, in steps 250 and 260, the same processing as in steps 150 and 160 of FIG. 3 is performed using the spring constant Km calculated in step 240.

According to the embodiment described above, the following effects can be obtained.
(2) At each processing timing, the spring constant Km is calculated using the displacement x (n) of the valve element 19 that is taken in each time and the previous command current amount I (n-1). Thus, even when the external force f expressed by the above equation (c3) cannot be ignored, a more appropriate command current amount can be calculated.

(Third embodiment)
Hereinafter, the third embodiment in which the control device for an electromagnetically driven valve according to the present invention is applied to a control device that opens and closes a valve body that functions as an intake valve or an exhaust valve of an internal combustion engine will be described as the first embodiment. The difference will be mainly described.

In this embodiment, feedback control of the state quantity X of the valve body 19 to the target state quantity Xm is performed by PID control.
Here, a processing procedure for calculating the command current amount in the present embodiment will be described with reference to FIG. The process of FIG. 5 is a process repeatedly executed by the ECU 50 at a predetermined cycle.

  In this series of processing, in steps 300 to 330, processing similar to that in steps 100 to 130 in FIG. 3 is performed. In step 340, each control gain is calculated by using the target displacement xm (n) of the valve body 19 calculated in step 320 and the current amount Im (n) assumed at the processing timing. That is, the control gain corresponding to each of the proportional term, the integral term, and the differential term with respect to the degree of deviation between the state quantity X of the valve body 19 and the target state quantity Xm is set as the target displacement xm (n). And the current amount Im (n) assumed to be calculated.

  Here, in the above equation (c14), the control gain appropriate for the physical system obtained when the retreated spring constant Km is calculated in the same manner as in the first embodiment is calculated. In practice, the control gain is desirably calculated using a two-dimensional map in which the displacement of the valve element 19 and the current amount I are map points and the control gain is a map value. However, the above equation (c14) may be calculated at each processing timing in the same manner as in the first embodiment, and the control gain may be calculated based on the calculation result.

When the calculation of the control gain is completed in this way, in step 350, the command current amount I (n) is calculated based on the calculated control gain, and this series of processes is temporarily ended.
According to the embodiment described above, the following effects can be obtained.

  (3) By calculating each control gain using a target displacement xm (n) of the valve body 19 and a current amount Im (n) assumed in advance, an appropriate command current amount I (n) is obtained. It becomes possible to calculate.

(Fourth embodiment)
Hereinafter, the fourth embodiment in which the control device for an electromagnetically driven valve according to the present invention is applied to a control device that opens and closes a valve body that functions as an intake valve or an exhaust valve of an internal combustion engine, and the third embodiment described above. The difference will be mainly described.

In this embodiment, feedback control of the state quantity X of the valve body 19 to the target state quantity Xm is performed by PID control.
Here, a processing procedure for calculating the command current amount in the present embodiment will be described with reference to FIG. The process of FIG. 6 is a process that is repeatedly executed by the ECU 50 at a predetermined cycle.

  In this series of processing, processing similar to that in steps 300 to 330 in FIG. 5 is performed in steps 400 to 430. In step 440, each control gain is calculated using the displacement x (n) of the valve element 19 taken in in step 400 and the previous command current amount I (n-1). That is, the control gain corresponding to each of the proportional term, the integral term, and the derivative term with respect to the degree of deviation between the state quantity X of the valve body 19 and the target state quantity Xm is set to the displacement x (n) of the valve body 19 and the previous time. It calculates using command electric current amount I (n-1).

  Here, in the above equation (c14), the control gain appropriate for the physical system acquired when the regressed spring constant Km is calculated in the same manner as in the second embodiment is calculated. In practice, the control gain is desirably calculated using a two-dimensional map in which the displacement of the valve element 19 and the current amount I are map points and the control gain is a map value. However, the above equation (c14) may be calculated at each processing timing in the same manner as in the second embodiment, and the control gain may be calculated based on the calculation result.

When the calculation of the control gain is completed in this way, in step 450, the command current amount I (n) is calculated using the calculated control gain, and this series of processes is temporarily ended.
According to the embodiment described above, the following effects can be obtained.

(4) By calculating each control gain using the displacement x (n) of the valve body 19 and the previous command current amount I (n−1), an appropriate command current amount I (n) is calculated. Will be able to.
(Other embodiments)
Each of the above embodiments may be modified as follows.

  The electromagnetic force assumed to be necessary for setting the state quantity of the valve body as a target state is not limited to that exemplified in the above equation (c10). For example, if the attenuation between the movable part and the fixed part can be ignored, the attenuation constant C may be set to “0” in the above equation (c10).

  The change in electromagnetic force with respect to the change in current from the amount of current required to generate the electromagnetic force that is assumed in advance to be necessary for setting the state quantity of the valve body to the target state is approximately linear. The feedback control for calculating the amount of current applied to the electromagnet based on the physical model approximated as a change is not limited to the sliding mode control.

  As a feedback control for calculating the amount of current to be applied to the electromagnet based on a physical model in which the change in electromagnetic force is approximated as a substantially linear change with respect to the change in current from the amount of current applied to the electromagnet, sliding control is possible. Not limited to mode control.

  As a method for manipulating the current amount based on a physical model in which a change in the electromagnetic force with respect to a change in an arbitrary current amount is approximated as a substantially linear change, the first and second embodiments and the modified examples are used. It is not restricted to what is illustrated in. For example, the above-mentioned arbitrary amount of current is applied to the electromagnet each time the amount of current necessary to generate the electromagnetic force assumed in advance to be necessary for setting the state amount of the valve body as a target state amount. It is good also as a weighted average value with the amount of current each time.

  In each of the above embodiments, the difference between the actual state quantity and the target state quantity is regarded as a minute change amount, and the feedback control mode is set based on this difference. However, the present invention is not limited to this. For example, instead of performing feedback control on the premise of a normative model in which the transition of the state quantity of the valve body is uniquely determined at each time, the target speed when the displacement of the valve body becomes a predetermined displacement is determined You may make it perform feedback control with respect to a thing. Even in such a case, the variable setting of the control gain based on the current amount applied to the electromagnet is effective. This is due to the following reason.

  That is, when the change amount ΔU of the electromagnetic force with respect to the change amount ΔI of the current applied to the electromagnet has nonlinearity, the change amount ΔU of the electromagnetic force is not only the current change amount ΔI but also the current amount I applied to the electromagnet. Dependent on this, ΔU = f (I) × ΔI. Therefore, for example, even if the proportional gain “P (xm−x)”, which is proportional to the difference between the target displacement xm and the actual displacement x, is defined as the current change amount ΔI, where P is the proportional gain. The corresponding change amount ΔU of the electromagnetic force changes according to the current amount I. For this reason, the proportional gain P may not be an appropriate value for all current amounts I. Therefore, if the control gain is variably set based on the current amount applied to the electromagnet, the control gain can be set to an appropriate value for each current amount applied to the electromagnet.

  -The amount of current applied to the electromagnet is not limited to the command current. For example, in a configuration including a drive circuit that controls the amount of current that actually flows through the electromagnet to the command current amount, the amount of current that the drive circuit outputs may be used.

  Instead of defining the displacement x of the valve body 19 as the distance between the electromagnet and the armature, it may be defined as the displacement of the umbrella portion 16, for example. In this case, the relationship between the displacement of the valve element and the distance between the electromagnet and the armature may not be uniquely determined due to the expansion of the valve shaft 20 or the like, but this may be regarded as a model error.

  In the above embodiment, only the opening driving electromagnet 62 is used during valve opening control of the valve body 19 and only the closing driving electromagnet 61 is used during valve closing control of the valve body 19, but this is not restrictive. . However, in this case, since the above equation (c7) is determined based on the distance between one of the electromagnets and the armature 28, the relationship between the displacement x of the valve element and the electromagnetic force is not necessarily the same as the equation (c7). It is necessary to consider what must not be done.

  The feedback control is not limited to PID control or sliding mode control, but may be H∞ control, for example. Even in such a case, it is assumed in advance that it is necessary to change the mode of the feedback control based on the amount of current applied to the electromagnet or to set the state quantity of the valve body as the target state quantity. It is effective to change the mode of the feedback control based on the amount of current required for generating the electromagnetic force to be generated. Here, “changing the feedback control mode based on the amount of current applied to the electromagnet” is used to change the feedback control mode as in the second and fourth embodiments. The current amount is not limited to only the current amount that is given to the electromagnet. For example, what changes the mode of feedback control according to the weighted average value of the current amount given to the electromagnet and the assumed current amount is also included. Further, “changing the feedback control mode based on the amount of current necessary for generating the electromagnetic force assumed in advance” means that the feedback control is performed as in the first and second embodiments. The amount of current used for changing the mode is not limited to the amount of current required for each time. For example, it includes one that changes the feedback control mode according to the weighted average value of the current amount applied to the electromagnet and the required current amount.

  -As an electromagnetically driven valve which drives a valve body with the electromagnetic force by an electromagnet, it does not restrict to what has the structure illustrated in previous FIG.

The figure which shows the whole structure of 1st Embodiment of the control apparatus of the electromagnetically driven valve concerning this invention. The figure which shows the physical model by which the variation | change_quantity of the electromagnetic force with respect to the variation | change_quantity of the electric current in the embodiment is approximated as a linear change. The flowchart which shows the procedure of the feedback control of the state quantity of the valve body concerning the embodiment. The flowchart which shows the procedure of the feedback control of the state quantity of a valve body in 2nd Embodiment of the control apparatus of the electromagnetically driven valve concerning this invention. The flowchart which shows the procedure of the feedback control of the state quantity of a valve body in 3rd Embodiment of the control apparatus of the electromagnetically driven valve concerning this invention. The flowchart which shows the procedure of the feedback control of the state quantity of a valve body in 4th Embodiment of the control apparatus of the electromagnetically driven valve concerning this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Exhaust valve, 12 ... Combustion chamber, 14 ... Exhaust port, 15 ... Valve seat, 16 ... Umbrella part, 18 ... Cylinder head, 19 ... Valve body, 20 ... Valve shaft, 21 ... Electromagnetic drive part, 22 ... Lower retainer, 24 ... Lower spring, 26 ... Armature shaft, 28 ... Armature, 30 ... Upper partition, 32 ... Upper core, 34 ... Lower core, 36 ... Upper cap, 38 ... Upper spring, 40, 44 ... Groove, 42 ... Upper coil, 46 ... Lower coil 50 ... ECU (electronic control unit), 52 ... displacement amount sensor, 61 ... electromagnet for closing drive, 62 ... electromagnet for opening drive.

Claims (9)

An electromagnetically driven valve control device applied to an electromagnetically driven valve that drives a valve body by electromagnetic force generated by an electromagnet, and feedback-controls the state quantity of the valve body to a target state quantity by operating an amount of current applied to the electromagnet In
The control device for an electromagnetically driven valve, wherein the feedback control mode is changed based on a current amount applied to the electromagnet each time. The change in the feedback control mode is that the amount of current applied to the electromagnet based on a physical model in which a change in the electromagnetic force with respect to a change in current from a current amount applied to the electromagnet is approximated as a substantially linear change. The control device for an electromagnetically driven valve according to claim 1, wherein the control device is calculated by calculating. The electromagnetically driven valve control device according to claim 1, wherein the change of the feedback control mode is performed as a variable setting of a control gain based on a current amount applied to the electromagnet each time. An electromagnetically driven valve control device applied to an electromagnetically driven valve that drives a valve body by electromagnetic force generated by an electromagnet, and feedback-controls the state quantity of the valve body to a target state quantity by operating an amount of current applied to the electromagnet In
Changing the aspect of the feedback control based on the amount of current required to generate the electromagnetic force assumed in advance to be the state quantity of the valve body as the target state quantity. A control device for an electromagnetically driven valve. The change of the feedback control mode is based on a physical model in which a change in the electromagnetic force with respect to a change in current from a current amount necessary for generating the electromagnetic force is approximated as a substantially linear change. The control device for an electromagnetically driven valve according to claim 4, wherein the control is performed by calculating an amount of current applied to the valve. The electromagnetically driven valve control device according to claim 4 or 5, wherein the change of the feedback control mode is performed as a variable setting of a control gain based on a current amount necessary for generating the electromagnetic force. An electromagnetically driven valve control device applied to an electromagnetically driven valve that drives a valve body by electromagnetic force generated by an electromagnet, and feedback-controls the state quantity of the valve body to a target state quantity by operating an amount of current applied to the electromagnet In
In the operation of the current amount, the nonlinearity of the change in the electromagnetic force with respect to the change in the current amount is taken into account. Applied to an electromagnetically driven valve that drives a valve element by electromagnetic force generated by an electromagnet, and controls the state quantity of the valve element to a target feedback state quantity by operating an amount of current applied to the electromagnet. In
A control device for an electromagnetically driven valve, wherein the current amount is manipulated based on a physical model in which a change in the electromagnetic force with respect to a change in an arbitrary current amount is approximated as a substantially linear change. An electromagnetically driven valve control device applied to an electromagnetically driven valve that drives a valve body by electromagnetic force generated by an electromagnet, and feedback-controls the state quantity of the valve body to a target state quantity by operating an amount of current applied to the electromagnet In
A control device for an electromagnetically driven valve, wherein a control gain for calculating the current amount is set in consideration of non-linearity of a change in the electromagnetic force with respect to a change in the current amount.

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