JP2006090206A - Control device for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable suitable control that follows changes in operating environment, by compensating for changes in the dynamic characteristics of a variable valve timing device due to disturbance factors such as the operating environment, manufacturing irregularity, and aging effect. <P>SOLUTION: A controller 41 is configured so as to obtain control duty which asymptotically makes agreeable the output of a control object model simulating the dynamic characteristics of the variable valve timing device 32 with the output of a reference model 40 simulating the ideal input/output characteristics of the device 32. Thus the control duty is calculated so that the difference between the output of the reference model 40 and actual valve timing becomes sufficiently small. When the difference becomes large as changes occur in the dynamic characteristics of the device 32 due to changes in the operating environment, the parameters of the controller 41 are adjusted one by one so as to make the difference adequately small with a parameter adjustment mechanism 42. These parameters, which are calculated one by one in the form that includes calculated items expressed by past record factors, reset the calculated values to the initial values for individual predetermined conditions of changes in the operating environment. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an automobile control apparatus that calculates an input of a control target from a target value using a model of the control target.

  In recent years, internal-combustion engines mounted on vehicles are equipped with a hydraulically driven variable valve timing device that varies the opening and closing timing of intake valves and exhaust valves with hydraulic pressure for the purpose of improving output, reducing fuel consumption, and reducing exhaust emissions. There is something. In this hydraulically driven variable valve timing device, the viscosity of the hydraulic oil changes depending on the temperature of the hydraulic oil (oil temperature) and the fluidity changes. Therefore, the responsiveness of the variable valve timing device (valve timing change speed) depends on the oil temperature. ) Will change.

  Therefore, by correcting the hydraulic control valve input of the variable valve timing device according to the oil temperature or cooling water temperature (oil temperature substitute information), the change in the responsiveness of the variable valve timing device due to the change in the oil temperature is compensated. There is something like that.

  However, it is difficult to accurately estimate the change in viscosity of the hydraulic oil from the oil temperature and the cooling water temperature, and the responsiveness of the variable valve timing device changes due to manufacturing variations and changes over time. Even if the control input of the hydraulic control valve of the variable valve timing device is corrected according to the temperature or the cooling water temperature, the change in the response of the variable valve timing device cannot be accurately compensated.

  As a countermeasure, for example, as described in Patent Document 1 (Japanese Patent No. 3134763), the control input (duty ratio) of the hydraulic control valve is set so that the valve timing change speed of the variable valve timing device becomes constant. Calculates the valve timing change speed when the value is held at a predetermined value, and corrects the control input (duty ratio) of the hydraulic control valve to correct the difference between the valve timing change speed and the specified speed. There is.

  However, the technique of Patent Document 1 compensates for a change in the behavior (static characteristics) of the variable valve timing device when the control input of the variable valve timing device (hydraulic control valve) is held at a constant value. The response characteristics (dynamic characteristics) of the variable valve timing device with respect to changes in the control input of the valve timing device are not considered at all. For this reason, changes in the dynamic characteristics of the variable valve timing device cannot be compensated for disturbance factors such as operating environment (oil temperature, etc.), manufacturing variations, and changes over time. There is a drawback that the control accuracy of the valve timing device is deteriorated.

In addition, since the change in the operating environment (oil temperature, etc.) is large during the warm-up process at the start of the internal combustion engine, the convergence of the deviation may deteriorate and the control accuracy may deteriorate unless this is fully considered. . Therefore, even if the operating environment (oil temperature or the like) changes greatly, it is required to increase the control accuracy of the variable valve timing device at this time more reliably.
Japanese Patent No. 3134763 (first page, FIG. 8 etc.)

  The present invention provides a vehicle control apparatus that can compensate for changes in dynamic characteristics of a controlled object due to disturbance factors such as operating environment, manufacturing variations, and changes over time, and enables suitable control following changes in the operating environment. The main purpose is to provide it.

  Hereinafter, effective means for solving the above-described problems will be described while showing effects.

  Means 1. The control apparatus for an automobile calculates a control target input from a target value of the control target using a control target model simulating the dynamic characteristics of the control target by the control input calculation means, and the control output detection means calculates the control target. And the parameter adjustment means adjusts the parameter of the control input calculation means based on the input of the control object or the relationship between the target value and the output of the control object. This parameter is calculated in a form including calculation items expressed using past history elements. Then, a change in the operating environment of the controlled object is detected by the operating environment detecting means, and the calculation item is reset to a predetermined value when a predetermined state determined within the range that the operating environment of the controlled object can take is detected by the resetting means. It is a thing.

  That is, when the dynamic characteristics of the controlled object change, the relationship between the input and output of the controlled object during the transition changes, and the controlled object input is calculated from the target value using the controlled object model. If the relationship between the input and output of the controlled object changes due to the change in the dynamic characteristics, the relationship between the target value and the output of the controlled object also changes. Therefore, if the parameter of the control input calculation means is adjusted based on the input of the control target or the relationship between the target value and the output, the parameter of the control input calculation means is adjusted to an appropriate value according to the change in the dynamic characteristics of the control target. can do. As a result, even if the dynamic characteristics of the controlled object change due to disturbance factors such as operating environment, manufacturing variation, aging, etc., the input of the controlled object is automatically adjusted according to the change in the dynamic characteristics of the controlled object, It is possible to compensate for changes in the dynamic characteristics of the controlled object due to disturbance elements.

  In addition, when using parameters that are calculated sequentially including calculation items expressed using past history elements, the operating environment (oil temperature, etc.) changes greatly during the warm-up process when the internal combustion engine is started. The followability and responsiveness to changes in the environment (oil temperature, etc.) may deteriorate, the deviation convergence may deteriorate, and the control accuracy may deteriorate. On the other hand, in this proposal, since the calculation item is reset to a predetermined value when the operating environment of the controlled object is in a predetermined state, it is possible to prevent deterioration of convergence of the deviation due to the parameter being pulled in the past history. Become. Thereby, the suitable control which followed the change of the operating environment can be performed.

  The difference between the output of the reference model and the output of the control target obtained when a reference model that simulates the desired input / output characteristics of the control target is set by the control input calculation means and the target value is input to the reference model. It is also possible to calculate the input of the control target so as to set 0 to 0. In this way, it is possible to accurately compensate for changes in the dynamic characteristics of the controlled object using the reference model.

  Mean 2. In the above means 1, a plurality of predetermined conditions of the operating environment are determined within a possible range of the operating environment to be controlled.

  That is, since the calculation item is reset a plurality of times within the range that the operating environment of the control target can take, the deviation of the parameter calculated this time from the desired parameter is reduced, and the operating environment can be changed more reliably. Can be followed.

  Means 3. In the above means 1 or 2, when the operation environment to be controlled is in a predetermined state, the reset means reads and resets the parameter corresponding to the predetermined state stored in the memory as a predetermined value, and the storage means The parameters at that time are stored in the memory in association with the predetermined state.

  That is, since the actual parameter obtained during the previous control is used as the predetermined value used for resetting the calculation item, the parameter can be made to follow the change in the operating environment more reliably.

  Means 4. In the above means 3, when the operating environment to be controlled is in a predetermined state, the reset means reads out a parameter associated with a predetermined state ahead of the predetermined state as a predetermined value from the memory and performs a reset.

  That is, as the predetermined value used for resetting the calculation item, a parameter associated with another predetermined state that is assumed to be in the future from when the current operating environment enters the predetermined state is used. The parameter can be made to follow the change of the operating environment more reliably.

  Means 5. In the above means 1, the parameter adjusting means calculates the deviation between the output of the controlled object model and the output of the controlled object when the controlled object input or the target value is input, and calculates to attenuate each time past history is overlaid. The parameter is calculated by multiplying the deviation as the item gain, and the reset means resets the gain to a predetermined value when the operating environment of the controlled object is in a predetermined state.

  That is, when the operating environment of the control target is in a predetermined state, the gain is reset to a predetermined value and becomes a high gain, so that the response of the parameter to the change in the operating environment becomes good, and the change in the operating environment is more reliably followed. be able to.

  Means 6. In any one of the above means 1 to 5, the control object is a hydraulically driven actuator that uses hydraulic oil whose temperature rises as the internal combustion engine warms up, and the operating environment detection means detects a change in the temperature of the hydraulic oil. The reset means resets the calculation item to a predetermined value when the temperature of the hydraulic oil reaches a predetermined temperature.

  That is, when applied to a hydraulically driven actuator that uses hydraulic oil that rises in temperature as the internal combustion engine warms up, the control input of the actuator is automatically corrected according to changes in the dynamic characteristics of the hydraulically driven actuator. It is possible to compensate for changes in the dynamic characteristics of the actuator due to disturbance factors such as operating environment, manufacturing variations, changes over time, etc., and to improve the control accuracy during the transient of the actuator, and variations in the transient response of the actuator Torque variation due to can be prevented. In addition, since the operating environment (oil temperature, etc.) varies greatly during the warm-up process at the start of the internal combustion engine, it is particularly effective to reset the calculation items to a predetermined value when the oil temperature of the hydraulic oil reaches a predetermined temperature. Yes, more suitable control can be performed following changes in the operating environment (such as oil temperature).

  Mean 7 In the means 6, it is determined whether the variable valve device composed of a hydraulically driven actuator is operated to advance or retard by the advance / delay determination means, and the reset means corresponds to the determination of the advance / delay angle. Reset is performed using a predetermined value corresponding to the determination of the advance / retarded angle among the predetermined values provided.

  Here, when the advance control of the variable valve device is performed, misfire or the like may occur due to overshoot (excessive advance), so it is required to reduce overshoot as much as possible. On the other hand, when the retard angle control is performed, it is required to return the valve timing earlier than the valve timing control accuracy. Therefore, the overshoot amount is allowed as compared with the advance angle control. For these reasons, generally, the variable valve timing device is configured so that the retard angle control can respond faster than the advance angle control. For this reason, if the advance angle control and the retard angle control are set to the same condition, the response on the advance angle side is not corrected and the response on the advance angle side is left uncorrected. There is a possibility that the response on the retarded angle side is not corrected but remains early without being corrected. For this reason, a predetermined value is prepared for each of the advance side and the retard side, and a parameter that matches the operating state of the variable valve device can be calculated by properly using the predetermined value based on the advance / delay determination. The accuracy can be increased more reliably.

  Hereinafter, an embodiment in which the present invention is embodied in a variable valve timing device for an on-vehicle gasoline engine which is an internal combustion engine will be described with reference to the drawings. First, a schematic configuration of the entire engine control system will be described with reference to FIG.

  In the engine 11 shown in FIG. 1, an air cleaner 13 is provided at the most upstream portion of the intake pipe 12, and an air flow meter 14 for detecting the intake air amount is provided downstream of the air cleaner 13. A throttle valve 15 whose opening is adjusted by a DC motor or the like and a throttle opening sensor 16 for detecting the throttle opening are provided on the downstream side of the air flow meter 14.

  A surge tank 17 is provided downstream of the throttle valve 15, and an intake pipe pressure sensor 18 for detecting the intake pipe pressure is provided in the surge tank 17. The surge tank 17 is provided with an intake manifold 19 for introducing air into each cylinder of the engine 11, and a fuel injection valve 20 for injecting fuel is attached in the vicinity of the intake port of the intake manifold 19 of each cylinder. ing. A spark plug 21 is attached to each cylinder of the engine 11 for each cylinder, and the air-fuel mixture in the cylinder is ignited by spark discharge of each spark plug 21.

  The exhaust pipe 22 of the engine 11 is provided with a catalyst 23 such as a three-way catalyst for purifying CO, HC, NOx and the like in the exhaust gas. An exhaust gas sensor 24 (air-fuel ratio sensor, oxygen sensor, etc.) for detecting lean or the like is provided. A cooling water temperature sensor 25 for detecting the cooling water temperature is attached to the cylinder block of the engine 11.

  As shown in FIG. 2, in the engine 11, the power from the crankshaft 26 is transmitted to the intake side camshaft 30 and the exhaust side camshaft 31 via the sprockets 28 and 29 by the timing chain 27 (or timing belt). It has become so. Further, the intake side camshaft 30 is provided with a variable valve timing device 32 composed of a hydraulically driven actuator. The variable valve timing device 32 changes the rotational phase (cam shaft phase) of the intake side camshaft 30 with respect to the crankshaft 26, and changes the valve timing of the intake valve 33 that is driven to open and close by the intake side camshaft 30. ing. The hydraulic circuit of the variable valve timing device 32 is supplied with hydraulic oil (engine oil) in an oil pan 34 by an oil pump 35, and the hydraulic pressure is controlled by a hydraulic control valve (OCV) 36, whereby the intake valve 33. The valve timing is controlled.

  A cam angle sensor 37 that outputs a cam angle signal for each predetermined cam angle is attached to the outer peripheral side of the intake side camshaft 30. On the other hand, a crank angle sensor 38 that outputs a crank angle signal for each predetermined crank angle is attached to the outer peripheral side of the crankshaft 26. The crank angle and engine speed are detected based on the output signal of the crank angle sensor 38, and the actual valve timing of the intake valve 33 is detected based on the output signal of the cam angle sensor 37 and the output signal of the crank angle sensor 38. The

  Outputs of the various sensors described above are input to an engine control circuit (hereinafter referred to as “ECU”) 39. The ECU 39 is mainly composed of a microcomputer, and executes various engine control programs stored in a built-in ROM (storage medium), so that the fuel injection amount of the fuel injection valve 20 can be changed according to the engine operating state. The ignition timing of the spark plug 21 is controlled.

  In addition, the ECU 39 executes each valve timing control program shown in FIGS. 4 to 9, so that the actual valve timing (actual cam timing) is based on the output signal of the cam angle sensor 37 and the output signal of the crank angle sensor 38. (Shaft phase) and a target valve timing (target camshaft phase) based on the engine operating state and the like, and the variable valve timing device 32 (hydraulic control valve 36) so that the actual valve timing matches the target valve timing. ) Is calculated.

  At that time, the ECU 39 executes model reference adaptive control as shown in FIG. In order to execute this model reference type adaptive control, a reference model 40 simulating the ideal input / output characteristics (response characteristics) of the controlled object (variable valve timing device) 32 is set, and the controller 41 outputs the reference model 40. The control input (control duty) is calculated so that the difference between the output of the control object 32 (actual valve timing) becomes zero. In addition, when the dynamic characteristics (input / output characteristics) of the controlled object 32 change due to changes in the operating environment such as the oil temperature, the difference between the output of the reference model 40 and the output of the controlled object 32 increases. The parameter of the controller 41 is adjusted by the mechanism 42 so that the difference becomes a sufficiently small value (near 0).

  Hereinafter, the design of the control system for the model reference adaptive control according to the present embodiment will be described.

  First, a controlled object model that simulates the dynamic characteristics of the controlled object (variable valve timing device) 32 is given as a linear model as shown below by the system identification method or the like.

ここで、ｕ（ｋ）は入力（制御デューティ）、ｙ（ｋ）は出力（実バルブタイミング）である。また、ａ1 は１回前の出力にかかる重み係数、ａ2 は２回前の出力にかかる重み係数、ｂは入力にかかる重み係数、ｂ1 は１回前の入力にかかる重み係数である。これらの重み係数は、例えば最小二乗法により算出すれば良い。

Here, u (k) is an input (control duty), and y (k) is an output (actual valve timing). Further, a1 is a weighting factor for the previous output, a2 is a weighting factor for the previous output, b is a weighting factor for the input, and b1 is a weighting factor for the previous input. These weighting factors may be calculated by, for example, the least square method.

  Next, the design of the controller 41 based on the controlled object model will be described.

  First, a reference model 40 that simulates an ideal input / output characteristic of the control target (variable valve timing device) 32 is given by the following equation.

ここで、ｕｍ（ｋ）は入力（目標バルブタイミング）、ｙｍ（ｋ）は出力（実バルブタイミング）である。また、ａｍ1 は１回前の出力にかかる重み係数、ａｍ2 は２回前の出力にかかる重み係数、ｂｍは入力にかかる重み係数、ｂｍ1 は１回前の入力にかかる重み係数、ｂｍ2 は２回前の入力にかかる重み係数である。

Here, um (k) is an input (target valve timing), and ym (k) is an output (actual valve timing). Also, am1 is a weighting factor for the previous output, am2 is a weighting factor for the previous output, bm is a weighting factor for the input, bm1 is a weighting factor for the previous input, and bm2 is twice. This is the weighting factor for the previous input.

  The controller 41 obtains a control input u (k) that asymptotically matches the output y (k) of the controlled object model of the above expression (1) and the output ym (k) of the reference model of the above expression (2). Is given by

ここで、ｂ0 及びＢＲ（ｚ-1）とＳ（ｚ-1）の多項式の係数ｂｒ1 ，ｂｒ2 ，ｂｒ3 ，ｂｒ4 ，ｓ0 ，ｓ1 ，ｓ2 は、未知のパラメータであり、パラメータ調整機構４２により制御対象３２の出力（実バルブタイミング）と規範モデル４０の出力ｙｍ（ｋ）との差が小さくなる又は０になるように調整される。

Here, the coefficients br1, br2, br3, br4, s0, s1, s2 of the polynomials b0 and BR (z-1) and S (z-1) are unknown parameters and are controlled by the parameter adjusting mechanism 42. The difference between the output of 32 (actual valve timing) and the output ym (k) of the reference model 40 is adjusted to be small or zero.

  The parameter adjustment mechanism 42 is given by the following equation.

以上説明したモデル規範型適応制御は、ＥＣＵ３９により図４〜図９に示すプログラムに従って実行される。以下、これらのプログラムの処理内容を説明する。

The model reference adaptive control described above is executed by the ECU 39 according to the programs shown in FIGS. Hereinafter, the processing contents of these programs will be described.

[Valve timing control]
The valve timing control program shown in FIG. 4 is executed at a predetermined cycle from the engine start. When this program is started, first, in step 101, output signals from the cam angle sensor 37, the crank angle sensor 38, the coolant temperature sensor 25, etc. are fetched, and the cam angle of the intake camshaft 30 and the crank angle of the engine 11 are captured. Then, the current cooling water temperature of the engine 11 is obtained.

  Thereafter, in step 102, the actual valve timing is calculated based on the output signal of the cam angle sensor 37 and the output signal of the crank angle sensor 38, and in the next step 103, the target valve timing is determined based on the engine operating state and the like. calculate.

  Thereafter, the process proceeds to step 104, and the ideal valve timing trajectory is calculated by calculating the output of the reference model 40 with respect to the target valve timing using the above equation (2). Here, the setting of the normative model 40 will be described. First, the engine rotational speed NE detected by the crank angle sensor 38 and the coolant temperature detected by the coolant temperature sensor 25 are read. The coolant temperature is used for estimating the oil temperature of the hydraulic oil in order to grasp the operating environment of the controlled object (variable valve timing device) 32 and detecting a change in the operating environment. In the case of a system including an oil temperature sensor that detects the oil temperature of hydraulic oil, the oil temperature detected by the oil temperature sensor may be read. Thereafter, the parameters am1 am2, bm, bm1, bm2 of the reference model 40 corresponding to the current coolant temperature (or oil temperature) and the engine speed NE are calculated using a map or the like. Thereby, an appropriate reference model 40 corresponding to the current coolant temperature (or oil temperature) and the engine speed NE is set.

  Thereafter, the process proceeds to step 105, where the parameter sequential adjustment program of FIG. 5 is executed at the sampling period of the actual valve timing (that is, the execution period of this program), and the difference between the output of the reference model 40 and the actual valve timing is sufficiently large. The parameter θ (k) of the controller 41 is adjusted so as to become smaller.

・ [Sequential parameter adjustment]
When this program is started, first, at step 201, it is determined whether or not the actual valve timing (VT) is skipped using the outputs of the cam angle sensor 37 and the crank angle sensor 38.

  As a result, when it is determined that there is an actual valve timing calculation skip (that is, when the actual valve timing calculation result is not detected within the execution interval of this program), the processing related to parameter adjustment after step 202 is not performed. In step 210, the previous value θ (k−1) of the parameter of the controller 41 is replaced with the current value θ (k).

  On the other hand, if it is determined in step 201 that there is no calculation of the actual valve timing, the process related to parameter adjustment after step 202 is executed as follows. First, in step 202, the advance / retard angle determination program shown in FIG. 6 is executed in order to determine whether the state of the variable valve timing device 32 to be controlled is the advance side or the retard side. To do.

・ ・ [Advance / Delay judgment]
When this program is started, first, in step 301, the previous value of the output of the reference model 40 is subtracted from the current value of the target valve timing (target VT), and whether or not the subtraction result has become larger than a predetermined value KHi. Determine. If “Yes” is determined in step 301, that is, if it is determined that the subtraction result is larger than KHi, the process proceeds to step 302, where the variable valve timing device 32 is operating on the advance side (intake-side camshaft). 30 cam angle is advanced with respect to the crank angle of the engine 11). Then, this program is terminated.

  On the other hand, if “No” is determined in step 301, that is, if it is determined that the subtraction result is equal to or lower than KHi, the process proceeds to step 303 to determine whether or not the subtraction result is smaller than a predetermined value KLo. However, KLo <KHi. If it is determined as “Yes” in step 303, that is, if it is determined that the subtraction result is smaller than KLo, the process proceeds to step 304, and the variable valve timing device 32 is operated on the retard side (intake-side camshaft 30). Is determined to be delayed with respect to the crank angle of the engine 11. Then, this program is terminated. If it is determined as “No” in step 303, that is, if the subtraction result is equal to or greater than KLo and equal to or less than KHi, it is determined that no advance / retard angle has occurred, and the program is terminated. To do.

  Next, the process returns to the above-described “parameter sequential adjustment” process, and step 203 of the parameter sequential adjustment program in FIG. 5 is executed. In step 203, the adaptive law execution determination program shown in FIG. 7 is executed in order to perform an adaptive law execution determination for calculating the difference ε (k) between the output of the reference model 40 and the actual valve timing.

.. [Adaptive law execution judgment]
When this program is started, first, in step 401, it is determined whether or not the target value is zero. If “Yes” is determined in step 401, that is, if the target value is determined to be 0, the process proceeds to step 402 to determine whether or not the actual valve timing (actual VT) is smaller than the predetermined value VTc. If “Yes” is determined in Step 402, that is, if it is determined that the actual valve timing is smaller than the predetermined value VTc, the difference ε between the output of the reference model 40 and the actual valve timing is reset to 0 in Step 403. End this program.

  On the other hand, if “No” is determined in either step 401 or step 402, that is, if the target value is not 0, or if it is determined in step 402 that the actual valve timing is greater than or equal to the predetermined value VTc, step 404 is performed. Then, using the above equation (8), the difference ε (k) between the output of the reference model 40 and the actual valve timing is calculated, and this program ends.

  Next, the process returns to the “parameter sequential adjustment” process described above, and step 204 of the parameter sequential adjustment program in FIG. 5 is executed. In step 204, a weight matrix calculation program shown in FIG. 8 is executed in order to calculate a weight matrix used for adjusting the parameter θ (k) of the controller 41.

・ ・ [Weight matrix calculation]
When this program is started, first, in step 501, it is determined whether or not the current value of the cooling water temperature (or oil temperature) is higher than the determination value T0. In step 502, the cooling water temperature (or oil temperature) is determined. It is determined whether or not the previous value is lower than the determination value T0. Here, the determination value T0 is set in a plurality of stages of, for example, 0 ° C., 20 ° C., 40 ° C., and 60 ° C. within a range that the cooling water temperature (or oil temperature) can take. Although the determination values T0 are set at equal intervals of 20 ° C., the determination values T0 may not be equal intervals. For example, the determination values T0 may be smaller as the temperature changes more greatly in the warm-up process when the engine 11 is started. Also, the determination value T0 may be one. If “No” is determined in either step 501 or step 502, the process proceeds to step 503, and the weight matrix Γ (k) is calculated using the above equation (7). Then, this program is terminated.

  On the other hand, when “Yes” is determined in both step 501 and step 502, that is, when the cooling water temperature (or oil temperature) exceeds the determination value T0 (for example, any one of 0 ° C., 20 ° C., 40 ° C., and 60 ° C.). Therefore, the process proceeds to step 504, and the previous value Γ (k−1) of the weight matrix (gain) of the parameter θ (k) used for calculating the parameter θ (k) is reset to the initial value Γ (0). The parameter θ (k) becomes a high gain by resetting the previous value Γ (k−1) of the weight matrix to the initial value Γ (0). Then, this program is terminated.

  Next, the process returns to the “parameter sequential adjustment” process described above, and step 205 of the parameter sequential adjustment program in FIG. 5 is executed. In step 205, it is determined whether or not the difference ε (k) between the output of the reference model 40 calculated in step 404 and the actual valve timing is greater than a predetermined value εA. Here, the predetermined value εA is set to a value corresponding to the allowable error. If “No” is determined in step 205, that is, if it is determined that ε (k) is equal to or less than the predetermined value εA, the process proceeds to step 210, and the previous value θ (k−1) of the parameter of the controller 41 as described above. Is replaced with the current value θ (k).

  On the other hand, if “Yes” is determined in step 205, that is, if it is determined that ε (k) is greater than the predetermined value εA, the process proceeds to step 206. This step 206 and the next step 207 are the same as the above-described steps 501 and 502, and the cooling water temperature (or oil temperature) is any one of the determination values T0 (in this case, for example, 0 ° C, 20 ° C, 40 ° C, 60 ° C). Only when it exceeds, the process proceeds to step 208, and the initial value θ (0) stored in the backup RAM 39a in the ECU 39 is read. As will be described later, each of the initial values θ (0) associated with the determination value T1 (20 ° C., 40 ° C., 60 ° C., 80 ° C.) of the cooling water temperature (or oil temperature) is stored in the backup RAM 39a. . Then, the initial value (0) associated with the determination value T1 that is one step higher in temperature than the current determination value T0, that is, the initial value associated with 20 ° C if the current determination value T0 is 0 ° C. If the value (0) is read and the initial value (0) associated with 40 ° C. is 40 ° C., the initial value (0) associated with 60 ° C. is 60 ° C., and 60 ° C. An initial value (0) associated with 80 ° C. is read. Then, the process proceeds to Step 209. On the other hand, if the coolant temperature (or oil temperature) does not exceed the determination value T0, the process proceeds to step 209 without going through step 208.

  Here, the above-described initial value θ (0) is the parameter θ stored in the RAM 39a for each determination value T0 of the cooling water temperature (or oil temperature) before or before the previous time (or before when the numerical value is not updated). Even if the determination value T0 is the same, two types of initial values θ (0) on the advance side and the retard side are stored in the RAM 39a. Accordingly, in the above step 208, the advance side based on the determination in the above step 202 within the initial value θ (0) on the advance side and the retard side corresponding to the determination value T0 of the cooling water temperature (or oil temperature). Alternatively, one of the initial values θ (0) on the retard side is read.

  This is because the control requirements differ between when the advance angle control is performed with respect to the actual valve timing and when the retard angle control is performed. For example, in advance angle control, misfire or the like may occur due to overshoot (excess advance angle), so it is required to reduce overshoot as much as possible. On the other hand, in the retard control, since it is required to return the valve timing earlier than the valve timing control accuracy, an overshoot amount is allowed as compared with the advance control. For these reasons, generally, the variable valve timing device is configured so that the retard angle control can respond faster than the advance angle control. For this reason, if the advance angle control and the retard angle control are set to the same condition, the response on the advance angle side is not corrected and the response on the advance angle side is left uncorrected. There is a possibility that the response on the retarded angle side is not corrected but remains early without being corrected. Therefore, initial values θ (0) are prepared for the advance side and the retard side, respectively. The initial value Γ (0) described above may also be prepared corresponding to the determination of the advance / delay angle.

  In step 209, the parameter θ (k) of the controller 41 is calculated using the above equations (6) to (10). The parameter θ (k) is adjusted so that the difference ε (k) between the output of the reference model 40 and the actual valve timing is sufficiently small. In this case, in order to calculate the parameter θ (k), the previous value θ (k−1) of the parameter and the previous value Γ (k−1) of the weight matrix are used, but the cooling water temperature (or oil temperature) is the determination value. When T0 (any of 0 ° C., 20 ° C., 40 ° C., and 60 ° C.) is exceeded, the previous value θ (k−1) is determined as a determination value T1 on the side whose temperature is one step higher than the current determination value T0. The initial value θ (0) associated with (20 ° C., 40 ° C., 60 ° C., 80 ° C.) is reset, and the weight matrix Γ (k) is reset to the initial value Γ (0).

  This is because the parameter θ (k) is calculated using the previous value θ (k−1) of the parameter when the parameter θ (k) is calculated this time as shown in the equation (6), and the past history is reflected long. Tend. Therefore, when there is a change in the operating environment where the viscosity gradually decreases as the temperature rises, such as the oil temperature, the deviation between the actual valve timing and the target valve timing is difficult to converge and the change speed is fast. In some cases, the deviation may increase and the divergence may occur. Therefore, the past history is not reflected by resetting to the initial value θ (0) corresponding to the determination value T0 for each determination value T0 of the coolant temperature (or oil temperature). In other words, the convergence of the deviation is prevented from being deteriorated by being pulled by the past history, and the control accuracy is improved. Further, since the weight matrix is also calculated using the previous value Γ (k−1), the past history tends to be reflected in the same manner. Therefore, by resetting the initial value Γ (0) corresponding to the determination value T0 for each determination value T0 of the cooling water temperature (or oil temperature), the past history is not reflected in the weight matrix Γ (k). In other words, the convergence of the deviation is prevented from being deteriorated by being pulled by the past history, thereby improving the control accuracy.

  In step 211, the RAM storage program shown in FIG. 9 is executed in order to store the parameter θ (k) obtained this time in the backup RAM 39a.

.. [RAM storage]
When this program is started, first, in step 601, it is determined whether or not the coolant temperature (or oil temperature) is a determination value T1 (for example, any one of 20 ° C., 40 ° C., 60 ° C., and 80 ° C.). The determination value T1 is set at an equal interval of 20 ° C. in the present embodiment corresponding to the determination value T0. Then, only when the cooling water temperature (or oil temperature) is the determination value T1, the process proceeds to Step 602, and the parameter θ (k) obtained in Step 209 or Step 210 is set to the determination value T1 (20 ° C., 40 ° C., 60 ° C.). , 80 ° C.) and stored in the backup RAM 39a. In this case, it is stored as the initial value θ (0) on the advance side in the determination on the advance side in step 202, and is stored as the initial value θ (0) on the retard side in the determination on the retard side. On the other hand, when the cooling water temperature (or oil temperature) is not the determination value T1, the parameter θ (k) is not stored. Although the storage in the RAM 39a is performed based on the cooling water temperature (or oil temperature), the engine speed NE may be considered in addition to the cooling water temperature (or oil temperature). Thereafter, the program is terminated.

  Thus, after performing the parameter sequential adjustment process, step 106 of the valve timing control program shown in FIG. 4 is executed. In step 106, a control input calculation program (not shown) is executed to calculate the control duty so that the difference between the output of the reference model 40 and the actual valve timing becomes zero.

  Specifically, the output of the reference model 40, the actual valve timing, and the past history of the control duty are read, and the parameter θ (k) of the controller 41 set by the parameter sequential adjustment program is read. When the actual valve timing is skipped, the output of the control target model (or the output of the reference model 40) of the above equation (1) is used as substitute information of the actual valve timing. Then, using the above equation (3), the control duty is calculated so that the difference between the output of the reference model 40 and the actual valve timing becomes zero.

  Further, when it is determined that the cooling water temperature (or oil temperature) is lower than the predetermined value, and the steady gain of the parameter θ (k) of the controller 41 is determined to be larger than the predetermined value, it is variable. It is determined that the characteristic of the valve timing device 32 has no linearity, that is, a dead zone, and dead zone removal control is executed. In this dead zone removal control, an auxiliary signal is input, or an appropriate process is performed on the control input of the variable valve timing device 32 (for example, the control input is raised to the nth power or the logarithm of the control input is taken), The controllability is ensured by making the characteristic of the variable valve timing device 32 pseudo linear. In step 106, a final control duty is determined.

  Thereafter, the process proceeds to step 107, where an auxiliary control area determination program (not shown) is executed to determine whether or not it is an auxiliary control area, and then this program ends. The ECU 39 sequentially executes the above-described processing programs to control the variable valve timing device 32 (hydraulic control valve 36).

  Next, the characteristic operational effects of the present embodiment will be described.

  In the present embodiment, the output of the control target model that simulates the dynamic characteristics of the variable valve timing device 32 (actual valve timing), and the output of the reference model 40 that simulates the ideal input / output characteristics of the variable valve timing device 32 The controller 41 is configured so as to obtain a control duty that asymptotically matches, and the dynamic characteristics of the variable valve timing device 32 change due to a change in the operating environment or the like, and the difference between the output of the reference model 40 and the actual valve timing Is increased, the parameter adjustment mechanism 42 sequentially adjusts the parameter θ (k) of the controller 41 so that the difference becomes sufficiently small. Therefore, even when the dynamic characteristics of the variable valve timing device 32 change due to disturbance factors such as operating environment, manufacturing variations, and changes over time, the control duty is automatically corrected according to the change in the dynamic characteristics of the variable valve timing device 32. Thus, it is possible to improve the control accuracy of the variable valve timing device 32 when it is excessive, and to prevent torque variations due to variations in the transient response of the variable valve timing device 32.

  In the present embodiment, the parameter θ (sequentially calculated in a form including the calculation items (parameter previous value θ (k−1), weight matrix previous value Γ (k−1)) expressed using past history elements is used. k) is used, the change in the operating environment (oil temperature, etc.) is large during the warm-up process at the start of the engine 11, and the followability and responsiveness to the change in the operating environment are deteriorated. Deteriorating and control accuracy may deteriorate. On the other hand, in the present embodiment, every time the change of the operating environment becomes a predetermined state (each time the cooling water temperature (or oil temperature) becomes the determination value T0), the parameter used for calculating the parameter θ (k). Since the previous value θ (k−1) and the weight matrix previous value Γ (k−1) are reset to the initial values θ (0) and Γ (0), respectively, the parameter θ (k) is a past history. It is possible to prevent the deviation convergence from deteriorating due to being pulled by the wire. Thereby, the suitable control which followed the change of the operating environment can be performed.

  In the present embodiment, a plurality of predetermined states (cooling water temperature (or oil temperature) determination value T0) of the operating environment for resetting are determined, and a plurality of resets are performed for each predetermined state. The deviation of the parameter calculated this time with respect to the parameter is reduced, and the change in the operating environment can be more reliably followed.

  Further, in the present embodiment, when the operating environment reaches a predetermined state (cooling water temperature (or oil temperature) determination value T1), the parameter θ (k) is associated with the predetermined state (determination value T1) and the initial value θ ( 0) is stored in the backup RAM 39a. Then, when the operating environment becomes a predetermined state (cooling water temperature (or oil temperature) determination value T0) at the time of the current control, the initial value associated with the determination value T1 on the side whose temperature is one step higher than the determination value T0. θ (0) is read from the RAM 39a and reset. That is, since the actual parameter θ (k) obtained at the previous control is used as the initial value θ (0) used for resetting, the parameter θ (k) can follow the change in the operating environment more reliably. it can.

  In this case, the initial value θ (0) used for reset corresponds to another predetermined state (the determination value T1 on the higher side) that is assumed to be in the future from the time when the current operating environment is in the predetermined state. Since the attached parameter θ (k) is used, it is possible to quickly respond to a change in the operating environment, and it is possible to cause the parameter θ (k) to follow the change in the operating environment more reliably.

  In this case, the parameter θ (k) is stored in the backup RAM 39a as the initial value θ (0) every time the cooling water temperature (or the oil temperature) becomes the determination value T1 having a predetermined interval, so the initial value θ (0 ) Is small and the amount of data stored in the RAM 39a is small.

  Further, in the present embodiment, when the operating environment reaches a predetermined state (cooling water temperature (or oil temperature) determination value T0), a weight matrix as a gain of the parameter θ (k) used for calculation of the parameter θ (k) The previous value Γ (k−1) is reset to the initial value Γ (0). The parameter θ (k) becomes a high gain by resetting the previous value Γ (k−1) of the weight matrix to the initial value Γ (0). Therefore, the responsiveness of the parameter θ (k) with respect to the change in the operating environment is improved, and the change in the operating environment can be more reliably followed.

  Further, in the present embodiment, the control target is the hydraulically driven variable valve timing device 32 that uses hydraulic fluid that rises in temperature as the engine 11 is warmed up. In particular, since the operating environment (oil temperature, etc.) varies greatly during the warm-up process when the engine 11 is started, the operating environment (oil temperature, etc.) of the variable valve timing device 32 is in a predetermined state (cooling water temperature (or oil temperature)). It is particularly effective to perform the above-described reset at the determination value T0), and it is possible to perform more suitable control following changes in the operating environment (oil temperature, etc.).

  Further, in the present embodiment, it is determined whether the variable valve timing device 32 is operating at an advance angle or a retard angle, and among the initial values θ (0) respectively provided corresponding to the determination of the advance / retard angle. Thus, the initial value θ (0) corresponding to the determination of the advance / retard angle is used for resetting. That is, as described above, since the variable valve timing device 32 has different control requirements for the advance angle control and the retard angle control, the initial value θ (0) is prepared for each of the advance side and the retard side. In addition, by properly using the initial value θ (0) based on the advance / retard angle determination, the parameter θ (k) that matches the operating state of the variable valve timing device 32 can be calculated, and the control accuracy is more reliably improved. be able to.

  In the present embodiment, when the difference ε (k) between the output of the reference model 40 and the actual valve timing is equal to or less than the predetermined value εA, the sequential adjustment of the parameter θ (k) is stopped. By providing a dead zone in the controller 41, it is possible to prevent erroneous learning of the parameter θ (k) due to disturbance such as noise, and it is possible to prevent divergence of the control system due to erroneous learning.

  In the present embodiment, the parameter θ (k) is adjusted at the sampling period of the actual valve timing. Therefore, the parameter θ (k) can be adjusted at an appropriate period synchronized with the sampling period of the actual valve timing. In addition, it is possible to reduce the calculation load on the ECU 39 by preventing the parameter θ (k) from being adjusted at a cycle faster than necessary. The parameter θ (k) may be adjusted at a cycle that is an integral multiple of the sampling cycle of the actual valve timing.

  In the present embodiment, when the actual valve timing calculation is skipped (when the calculation result of the actual valve timing is not detected within a predetermined period), the sequential adjustment of the parameter θ (k) is stopped and the actual valve timing is stopped. Since the control duty is calculated using the output of the control target model (or the output of the reference model 40) instead of the control valve, the calculation processing of the control duty should be continued even when the calculation of the actual valve timing is skipped. Can do. Further, by stopping the sequential adjustment of the parameter θ (k), it is possible to prevent erroneous learning of the parameter θ (k) due to skipping calculation of the actual valve timing.

  In addition, this invention is not limited to the content of description of the said embodiment, For example, you may implement as follows.

  In the above embodiment, the parameters of the controller 41 are sequentially adjusted so that the difference between the output of the reference model 40 and the actual valve timing is sufficiently small. However, the difference between the output of the reference model 40 and the actual valve timing is used. The parameters of the controlled object model may be adjusted sequentially so that the value becomes sufficiently small.

  In the above embodiment, when the difference between the output of the reference model 40 and the actual valve timing becomes equal to or smaller than the predetermined value, the sequential adjustment of the parameters is stopped. However, the actual valve timing and the output of the control target model When the difference between the values becomes equal to or less than a predetermined value, the sequential parameter adjustment may be stopped.

  In the above embodiment, the present invention is applied to the variable valve timing device that varies the valve timing of the intake valve. However, the variable valve device that varies the valve lift amount and valve opening period of the intake valve, the valve opening / closing characteristics of the exhaust valve (valve timing) , At least one of a valve lift amount and a valve opening period), and widely applied to various control objects used for control of automobiles and internal combustion engines, and control objects other than internal combustion engines. Also good.

  In the above embodiment, the present invention is applied to a control system having a reference model, but is applied to various control systems that calculate a control input from a target value of a controlled object using a controlled object model that simulates the dynamic characteristics of the controlled object. May be.

It is a schematic block diagram of the whole engine control system in one embodiment of this invention. It is a schematic block diagram of a valve timing control system. It is a block diagram which shows the function of model normative type adaptive control. It is a flowchart which shows the flow of a process of a valve timing control program. It is a flowchart which shows the flow of a process of a parameter sequential adjustment program. It is a flowchart which shows the flow of a process of an advance angle / retard angle determination program. It is a flowchart which shows the flow of a process of an adaptive law execution determination program. It is a flowchart which shows the flow of a process of a weight matrix calculation program. It is a flowchart which shows the flow of a process of RAM storage program.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 32 ... Variable valve timing device (hydraulic drive actuator, variable valve device and control object), 25 ... Cooling water temperature sensor (operating environment detection means), 33 ... Intake valve, 34 ... Oil pan, 35 ... Oil pump, 36 ... Hydraulic control valve, 37 ... Cam angle sensor (control output detection means), 39 ... ECU (control input calculation means, parameter adjustment means, reset means, advance / delay angle determination means), 39a ... Backup RAM (Memory), θ (k) ... parameter, θ (k-1) ... previous value of parameter (calculation item), θ (0) ... initial value (predetermined value), Γ (k) ... weight matrix (calculation item, Gain), Γ (0)... Initial value (predetermined value).

Claims (7)

Control input calculation means for calculating an input of the control object from a target value of the control object using a control object model simulating the dynamic characteristics of the control object of the automobile;
Control output detecting means for detecting the output of the controlled object;
Parameter adjusting means for adjusting a parameter of the control input computing means based on the relationship between the input of the control object or the target value and the output of the control object,
A control device that sequentially calculates the parameters in a form that includes calculation items represented using past history elements,
An operating environment detecting means for detecting a change in the operating environment of the controlled object;
Reset means for resetting the calculation item to a predetermined value when a predetermined state determined within a range that can be taken by the operating environment of the control object;
An automobile control device comprising:   The vehicle control apparatus according to claim 1, wherein a plurality of predetermined states of the operating environment are determined within a range that the operating environment of the control target can take. Storage means for storing the parameters in a memory;
When the operating environment of the controlled object is in a predetermined state, the reset unit reads out the parameter corresponding to the predetermined state stored in the memory as the predetermined value, and resets the storage unit. The vehicle control device according to claim 1, wherein the parameter at that time is stored in a memory in association with a predetermined state. A plurality of predetermined states of the operating environment are determined within a possible range of the operating environment of the control target,
When the operating environment of the control target is in a predetermined state, the reset unit reads the parameter associated with another predetermined state assumed to be in the future from the memory as the predetermined value, and performs a reset. The vehicle control apparatus according to claim 3. The parameter adjustment means calculates a deviation between the output of the control target model and the output of the control target when the control target input or the target value is input, and attenuates each time a past history is overlaid. The parameter is calculated by multiplying the deviation by a gain as a calculation item,
2. The automobile control device according to claim 1, wherein the reset unit resets the gain to the predetermined value when an operating environment of the control target is in a predetermined state. The control object is a hydraulically driven actuator that uses hydraulic oil that rises in temperature as the internal combustion engine warms up,
The operating environment detecting means detects a change in temperature of the hydraulic oil,
6. The automobile control device according to claim 1, wherein the reset unit resets the calculation item to a predetermined value when an oil temperature of the hydraulic oil reaches a predetermined temperature. 7. The hydraulically driven actuator is a variable valve device that varies a valve opening / closing characteristic of an intake valve or an exhaust valve of an internal combustion engine,
Advancing / retarding angle determining means for determining whether the variable valve device is operating at an advance angle or a retard angle;
The predetermined value is provided corresponding to the determination of the advance / retard angle,
7. The vehicle control apparatus according to claim 6, wherein the reset unit resets the vehicle based on the determination of the advance / retard angle using the predetermined value corresponding to the determination.

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