JP2021038722A - Control device and valve timing adjustment system using the same - Google Patents

Abstract

To provide a control device capable specifying a dead band of a hydraulic actuator in a short period of time.SOLUTION: A control portion 51 controls an operation of a hydraulic actuator 30 by a control signal output to an OCV 10. A dead band specification portion 52 specifies a dead band as a region free from response of the hydraulic actuator 30 corresponding to change of the control signal in a signal zone to which the control signal is output, or a region of low responsiveness. The dead band specification portion 52 specifies the dead band by learning an upper end and a lower end of the dead band by estimating a speed bending point as a sudden change portion of a speed of the operation of the hydraulic actuator 30 on the basis of the speed when the specific control signal is output to the OCV 10. The control portion 51 outputs the control signal to the OCV 10 on the basis of the dead band specified by the dead band specification portion 52, and controls the operation of the hydraulic actuator 30.SELECTED DRAWING: Figure 1

Description

The present invention relates to a control device and a valve timing adjustment system using the control device.

Conventionally, there is known a control device that controls an adjusting device including a hydraulic actuator that operates by supplying or discharging hydraulic oil and a control valve that controls the supply or discharge of hydraulic oil to the hydraulic actuator. Further, there is known a valve timing adjusting system which includes an adjusting device and a control device and can adjust the valve timing of an internal combustion engine by controlling the adjusting device by the control device.

For example, in the control device of Patent Document 1, the deviation of the response characteristic is learned based on the deviation between the operating speed of the hydraulic actuator and the reference value when the control signal is forcibly output to the control valve, and the control valve is controlled. doing.

Japanese Patent No. 5182388

In the control device of Patent Document 1, it is unclear where the sudden change part of the operation speed of the hydraulic actuator exists. Therefore, in order to enhance the learning system, it is necessary to perform a large number of tests with fine test pattern steps.

In addition, in order not to adversely affect the engine output and emissions, it is necessary to set restrictions on the learning execution conditions, and learning opportunities are reduced, so that it takes an enormous amount of time to complete the learning. Therefore, there is a possibility that the original performance of the vehicle cannot be exhibited until the learning is completed.

In addition, when the dead zone, which is the region where the hydraulic actuator does not respond to the change in the control signal or has low responsiveness in the signal range where the control signal is output, is defined by the speed threshold value, it is cold, warm, or individual. The speed characteristics differ depending on the difference. Therefore, there is a risk of erroneously learning the dead zone. Alternatively, it is necessary to prepare a huge threshold map according to the operating state.

An object of the present invention is to provide a control device capable of identifying a dead zone of a hydraulic actuator in a short time, and a valve timing adjustment system using the control device.

A first aspect of the present invention is an adjusting device (2) including a hydraulic actuator (30) that operates by supplying or discharging hydraulic oil and a control valve (10) that controls the supply or discharge of hydraulic oil to the hydraulic actuator. The control device (50) is provided with a control unit (51) and a dead zone identification unit (52).

The control unit controls the operation of the hydraulic actuator by a control signal output to the control valve. The dead zone specifying unit identifies a dead zone in the signal range in which the control signal is output, which is a region where the hydraulic actuator does not respond to a change in the control signal or the response is low.

The dead zone identification part learns the upper end and the lower end of the dead zone by estimating the speed bending point which is a sudden change part of the speed based on the speed of operation of the hydraulic actuator when a specific control signal is output to the control valve. By doing so, the dead zone is identified.

The control unit outputs a control signal to the control valve based on the dead zone specified by the dead zone specifying unit, and controls the operation of the hydraulic actuator.

In this embodiment, the dead zone specifying portion estimates the speed bending point, which is a sudden change portion of the speed, based on the operating speed of the hydraulic actuator when a specific control signal is output to the control valve. Can be identified in a short time.

In the second aspect of the present invention, the dead zone specifying portion determines the speed bending point, which is a sudden change portion of the speed, based on the rate of change of the operating speed of the hydraulic actuator when a specific control signal is output to the control valve. The dead zone is identified by learning the upper and lower ends of the dead zone by estimating.

In this embodiment, the dead zone specifying portion estimates the speed bending point, which is a sudden change portion of the speed, based on the rate of change in the operating speed of the hydraulic actuator when a specific control signal is output to the control valve. Similar to the first aspect, the dead zone of the hydraulic actuator can be specified in a short time.

The figure which shows the control device and the valve timing adjustment system of 1st Embodiment. The characteristic diagram which shows the relationship between the control signal in the adjustment device and the displacement speed of a hydraulic actuator. The figure for demonstrating the outline of control of the control valve by the control apparatus of 1st Embodiment. The figure for demonstrating the outline of control of the control valve by the control apparatus of 1st Embodiment. The figure for demonstrating the outline of control of the control valve by the control apparatus of 1st Embodiment. The flowchart which shows the process about control of the control valve by the control device of 1st Embodiment. The flowchart which shows the process about the identification of the dead zone by the control device of 1st Embodiment. The figure which shows the pattern of the control signal output to the control valve by the control device of 1st Embodiment, and the phase change of a hydraulic actuator. The figure which shows the operating speed of the hydraulic actuator when a specific control signal is output to the control valve by the control device of 1st Embodiment. The figure for demonstrating the process when the oil temperature is high about the process which concerns on the identification of a dead zone by the control device of 1st Embodiment. The figure for demonstrating the process when the oil temperature is low about the process concerning the identification of a dead zone by the control device of 1st Embodiment. The figure for demonstrating the accuracy of the process when the oil temperature is different about the process concerning the identification of a dead zone by the control device of 1st Embodiment. The figure for demonstrating the accuracy of the processing when the average cam torque is different about the processing concerning the identification of a dead zone by the control device of 1st Embodiment. The figure for demonstrating the accuracy of the process when the oil temperature is different about the process which concerns on the identification of a dead zone by the control device of the comparative form. The figure for demonstrating the accuracy of the processing when the average cam torque is different about the processing concerning the identification of a dead zone by the control device of the comparative form. The flowchart which shows the process about the identification of the dead zone by the control device of 2nd Embodiment. The figure for demonstrating the process which concerns on the identification of a dead zone by the control device of 2nd Embodiment. The flowchart which shows the process about the identification of the dead zone by the control device of 3rd Embodiment. The figure for demonstrating the process which concerns on the identification of a dead zone by the control device of 3rd Embodiment. The flowchart which shows the process about the identification of the dead zone by the control device of 4th Embodiment. The figure for demonstrating the process which concerns on the identification of a dead zone by the control device of 4th Embodiment. The flowchart which shows the process about the identification of the dead zone by the control device of 5th Embodiment. The figure for demonstrating the process which concerns on the identification of a dead zone by the control device of 5th Embodiment.

Hereinafter, the control device and the valve timing adjustment system according to a plurality of embodiments will be described with reference to the drawings. In the plurality of embodiments, substantially the same constituent parts are designated by the same reference numerals, and the description thereof will be omitted.

(First Embodiment)
The control device of the first embodiment and the valve timing adjustment system to which the control device is applied are shown in FIG. The valve timing adjustment system 1 is mounted on a vehicle (not shown), includes a valve timing adjustment device 2 and a control device 50 as "adjustment devices", and controls the valve timing adjustment device 2 by the control device 50 to "internal combustion". The valve timing of the engine 5 as an "engine" can be adjusted. In the present embodiment, the valve timing adjustment system 1 can adjust the valve timing of the intake valve of the engine 5.

As shown in FIG. 1, the valve timing adjusting device 2 includes a hydraulic actuator 30 and an OCV 10 as a “control valve”. The hydraulic actuator 30 changes the displacement angle, that is, the phase of the camshaft 4 with respect to the crankshaft 3 of the engine 5. The hydraulic actuator 30 has a housing 31, a rotor 32, and the like. The housing 31 rotates in synchronization with the crankshaft 3. The rotor 32 is provided in the housing 31 and rotates in synchronization with the cam shaft 4. Inside the housing 31, the rotor 32 partitions the advancing chamber 33 and the retarding chamber 34 as a "hydraulic chamber" from the housing 31.

The hydraulic actuator 30 operates by supplying hydraulic oil to the advance angle chamber 33 and the retard angle chamber 34 and changing the rotation angle of the rotor 32 with respect to the housing 31. When the hydraulic oil is supplied to the advance chamber 33, the hydraulic actuator 30 operates so as to change the displacement angle, that is, the phase of the cam shaft 4 with respect to the crankshaft 3 to the advance angle side. On the other hand, when the hydraulic oil is supplied to the retard chamber 34, the hydraulic actuator 30 operates so as to change the displacement angle, that is, the phase of the cam shaft 4 with respect to the crankshaft 3 to the retard angle side. At this time, the internal hydraulic oil is pushed out and discharged from the "hydraulic chamber" on the side where the hydraulic oil is not supplied as the "hydraulic chamber" on the side where the hydraulic oil is supplied expands.

The hydraulic oil supplied to the hydraulic actuator 30 is pumped from the oil pump 41 driven by the engine 5. The OCV 10 is provided between the oil pump 41 and the hydraulic actuator 30. The OCV 10 is, for example, a 4-port spool valve, and has a sleeve 11, a spool 12, a spring 13, a solenoid 14, and the like. The OCV 10 can control the supply or discharge of hydraulic oil to the advance chamber 33 and the retard chamber 34 of the hydraulic actuator 30 by the position of the spool 12 with respect to the sleeve 11.

The OCV 10 has a supply port 21, an advance port 22, a retard port 23, and a drain port 24. The supply port 21 is connected to the oil pump 41. The advance angle port 22 is connected to the advance angle chamber 33. The retard angle port 23 is connected to the retard angle chamber 34. The drain port 24 is connected to the oil pan 42.

One end of the spool 12 in the moving direction is supported by the spring 13, and the other end is supported by the solenoid 14. The position of the spool 12 in the sleeve 11 can be controlled by the duty of the drive current as the "control signal" supplied to the solenoid 14 (hereinafter, appropriately referred to as "OCV drive duty").

At the position of the spool 12 shown in FIG. 1, the communication between the advance angle port 22, the retard angle port 23, the supply port 21, and the drain port 24 is cut off, and the hydraulic oil is supplied to the advance angle chamber 33 and the retard angle chamber 34. And virtually no emissions. Hereinafter, the operating range of the spool 12 in which the communication between the advance port 22, the retard port 23, the supply port 21, and the drain port 24 is cut off is referred to as a “neutral range”.

When the OCV drive duty is increased while the spool 12 is in the neutral region, the spool 12 is pushed by the solenoid 14 to move. As a result, the advance angle port 22 and the supply port 21 communicate with each other, and the retard angle port 23 and the drain port 24 communicate with each other to supply the hydraulic oil to the advance angle chamber 33 and discharge the hydraulic oil from the retard angle chamber 34. Will be performed at the same time. Hereinafter, the operating range of the spool 12 when the hydraulic oil is supplied to the advance angle chamber 33 is referred to as an “advance angle range”.

On the other hand, when the OCV drive duty is reduced while the spool 12 is in the neutral region, the spool 12 is pushed by the spring 13 and moves. As a result, the advance angle port 22 and the drain port 24 communicate with each other, and the retard angle port 23 and the supply port 21 communicate with each other to supply the hydraulic oil to the retard angle chamber 34 and discharge the hydraulic oil from the advance angle chamber 33. Will be performed at the same time. Hereinafter, the operating range of the spool 12 when the hydraulic oil is supplied to the retard angle chamber 34 is referred to as a “retard angle range”.

FIG. 2 shows the relationship between the OCV drive duty in the valve timing adjusting device 2 and the operating speed of the hydraulic actuator 30, that is, the displacement speed of the hydraulic actuator 30 (the speed of change of the displacement angle of the camshaft 4 with respect to the crankshaft 3). It is a characteristic diagram. As shown in FIG. 2, in the valve timing adjusting device 2, the displacement speed of the hydraulic actuator 30 is changed with respect to a change in the duty value in the vicinity of the duty (hereinafter referred to as “holding duty”) in which the displacement speed of the hydraulic actuator 30 is held at zero. There is a "dead zone" in which the change in the duty value is small, that is, the response to the change in the duty value is low. Here, the "neutral region" is formed with a certain width. The OCV drive duty range when the spool 12 is in the neutral region becomes a dead zone.

When the OCV drive duty is increased beyond the dead zone, the displacement speed of the hydraulic actuator 30 begins to increase toward the advance angle side and changes linearly with the change in the OCV drive duty. This is because the operating range of the spool 12 has entered the advance range from the neutral range. When the OCV drive duty is increased to a certain extent, the displacement speed of the hydraulic actuator 30 reaches the maximum advance angular velocity, and even if the OCV drive duty is further increased, the displacement speed is kept constant. At this time, the spool 12 moves to the limit position of the advance angle region, and the advance angle port 22 and the supply port 21 are completely communicated with each other, and the retard angle port 23 and the drain port 24 are completely communicated with each other. There is.

On the other hand, when the OCV drive duty is reduced beyond the dead zone, the displacement speed of the hydraulic actuator 30 begins to increase toward the retard side and changes linearly with the change in the OCV drive duty. This is because the operating range of the spool 12 has entered the retard range from the neutral range. When the OCV drive duty is reduced to a certain extent, the displacement speed of the hydraulic actuator 30 reaches the maximum retard angle speed, and even if the OCV drive duty is further reduced, the displacement speed is kept constant. At this time, the spool 12 moves to the limit position in the retarded angle region, and the advance angle port 22 and the drain port 24 are completely communicated with each other, and the retard angle port 23 and the supply port 21 are completely communicated with each other. There is.

The control device 50 is, for example, an electronic control unit (“ECU”), and is a small computer including a CPU as a calculation unit, a ROM and RAM as a storage unit, an I / O as an input / output unit, and the like. The control device 50 controls devices, devices, and the like provided in each part of the vehicle based on signals and the like from various sensors provided in the vehicle (not shown).

The control device 50 controls the operation of the OCV 10. The valve timing adjustment system 1 is composed of the control device 50 and the mechanical portion (valve timing adjustment device 2) including the hydraulic actuator 30 and the OCV 10. The control device 50 has a control unit 51 and a dead zone identification unit 52 as conceptual functional units.

The control unit 51 of the control device 50 sets the target displacement angle of the camshaft 4 with respect to the crankshaft 3, and calculates the “OCV drive duty” based on the deviation between the actual displacement angle (control displacement angle) and the target displacement angle. To do. The control device 50 outputs the calculated OCV drive duty to the OCV 10 as a “control signal”.

In this way, the control unit 51 can control the operation of the hydraulic actuator 30 by the control signal output to the OCV 10.

The target displacement angle is a displacement angle for obtaining the optimum valve timing according to the operating state of the engine 5, and is determined from a map having the operating state of the engine 5 as a parameter. The control displacement angle can be calculated from the output signal of the crank angle sensor 61 and the output signal of the cam angle sensor 62.

Hereinafter, the control of the OCV 10 by the control device 50 will be described with reference to FIGS. 3 and 4. The control device 50 stores the control characteristics of the hydraulic actuator 30 realized when a virtual model control valve (hereinafter, referred to as “virtual OCV”) is used as the OCV as “model control characteristics”. In the "model control characteristics", the relationship between the OCV drive duty and the displacement speed of the hydraulic actuator 30 is not fixed, and the change in the OCV drive duty when the center of the dead zone (hereinafter referred to as "OCV center") is used as a reference. The tendency of the displacement speed of the hydraulic actuator 30 to change is set. Specifically, the characteristic line as shown in the lower part of FIG. 3 is stored as a model control characteristic.

The control characteristics of the OCV 10 are shown by characteristic lines in the upper part of FIG. However, there are individual differences in the actual control characteristics of OCV10. Further, the control characteristics of the OCV 10 change depending on the conditions such as the oil temperature. Therefore, it is difficult to specify the actual control characteristics of the OCV 10 in advance. Therefore, in the present embodiment, the control device 50 uses the above model control characteristics and estimates the actual control characteristics of the OCV 10 from the minimum data regarding the control characteristics.

The control device 50 identifies the dead zone and the holding duty of the OCV 10 as the minimum data regarding the control characteristics of the OCV 10. That is, the dead zone specifying unit 52 of the control device 50 identifies a "dead zone" in the signal range in which the control signal is output, which is a region where the hydraulic actuator 30 does not respond to a change in the control signal or has low responsiveness. ..

The dead zone of the OCV 10 is learned in the process of controlling the operation of the hydraulic actuator 30 by the duty control of the OCV 10. The “processing of learning the dead zone” by the dead zone specifying unit 52 of the control device 50 will be described later.

Since the dead zone of the virtual OCV is known as the model dead zone, if the dead zone of the OCV 10 (actual OCV dead zone) is specified, the ratio of the real OCV dead zone width to the virtual OCV dead zone width can be calculated. This ratio is a correspondence coefficient for associating the OCV 10 with the virtual OCV, and can be used as a coefficient for correcting the variation in the control characteristics of the actual OCV 10 with respect to the virtual OCV.

As shown in Equation 1 below, in the present embodiment, the ratio of the actual OCV dead band width to the virtual OCV dead band width is defined as the “OCV variation correction coefficient”.
OCV variation correction coefficient = actual OCV dead band width / virtual OCV dead band width ... Equation 1

The holding duty of the OCV 10 is learned in the process of controlling the operation of the hydraulic actuator 30 by the duty control of the OCV 10. In the present embodiment, the holding duty learning method is not limited, and any method may be used. For example, when the target displacement angle has not changed for more than a certain period of time and the control displacement angle has not changed for more than a certain period of time, the OCV drive duty at that time is held as the holding duty (“holding duty learning value”). ), Etc. can be used.

If the holding duty of the OCV 10 can be specified by learning, the amount of deviation of the holding duty from the OCV center can be obtained. Here, it is assumed that the amount of deviation of the holding duty from the OCV center in the actual OCV 10 is proportional to the amount of deviation of the holding duty from the OCV center in the virtual OCV. Further, it is assumed that the OCV center in the actual OCV 10 coincides with the OCV center in the virtual OCV. Under such conditions, the holding duty of the virtual OCV calculated by the following equation 2 is defined as the “virtual OCV holding duty learning value”.
Virtual OCV holding duty learning value = (holding duty learning value-OCV center) / OCV variation correction coefficient + OCV center ... Equation 2

The control device 50 controls the duty of the OCV 10 by feedback control based on the deviation between the control displacement angle of the hydraulic actuator 30 and the target displacement angle. PD control is used for feedback control. The control device 50 stores in advance the relationship between the engine speed, which is the rotation speed of the engine 5 (crankshaft 3), the oil temperature, and the control gain as map data.

Of the P control and the D control in the PD control, the control amount of the P control is calculated from the deviation between the control displacement angle and the target displacement angle and the P control gain. The control amount of D control is calculated from the change speed of the deviation between the control displacement angle and the target displacement angle and the D control gain. Hereinafter, the P control amount and the D control amount in the virtual OCV are collectively referred to as a "basic control amount".

The control device 50 calculates a basic control amount according to the deviation using the map data, and adds it to the virtual OCV holding duty learning value. The value obtained by adding the basic control amount to the virtual OCV holding duty learning value is the OCV drive duty to be output in the virtual OCV. Hereinafter, the OCV drive duty to be output in the virtual OCV is referred to as "basic duty".

The basic duty is a duty at which an optimum control result can be obtained in the control characteristics of the virtual OCV. In the actual OCV10, in order to obtain the optimum control result, it is necessary to convert the basic duty to a value suitable for the control characteristics of the actual OCV10. At that time, it is also necessary to consider the dead zone of OCV10. This is because the change in the displacement speed of the hydraulic actuator 30 with respect to the change in the OCV drive duty differs greatly depending on whether the OCV drive duty is in the dead zone or outside the dead zone.

In the present embodiment, as shown in the lower stages of FIGS. 4 and 5, the control device 50 has the basic control amount inside the virtual OCV dead zone and outside the virtual OCV dead zone. It is classified into "virtual OCV insensitive out-of-band control amount". FIG. 4 shows a case where the basic duty exceeds the virtual OCV dead zone and is outside the virtual OCV dead zone, and FIG. 5 shows a case where the basic duty is within the virtual OCV dead zone.

The control device 50 converts each of the virtual OCV dead zone control amount and the virtual OCV dead zone control amount, calculates the control amount in the actual OCV dead zone from the virtual OCV dead zone control amount, and performs the virtual OCV dead zone control. From the quantity, the controlled quantity outside the actual OCV dead zone is calculated.

The value obtained by adding the actual OCV dead zone control amount and the actual OCV dead zone out control amount calculated as described above to the holding duty learning value is the “OCV drive duty” output to the actual OCV 10. That is, the OCV drive duty can be calculated by the following equation 3.
OCV drive duty = actual OCV dead zone control amount + actual OCV dead zone control amount + holding duty learning value ... Equation 3

By controlling the OCV 10 by the above method, it is possible to suppress the influence of variations in control characteristics due to individual differences of the OCV 10 and improve the controllability of the hydraulic actuator 30, particularly the controllability of the OCV 10 outside the dead zone. .. By using the model control characteristics of the virtual OCV as described above, the control characteristics of the actual OCV10 can be estimated only by specifying the dead zone and the holding duty of the actual OCV10, and based on the estimated control characteristics. The operation of the hydraulic actuator 30 can be controlled.

Hereinafter, the control method of the OCV 10 of the present embodiment, that is, the process related to the control will be described more specifically. The flowchart shown in FIG. 6 shows the process S100 for calculating the control amount output to the OCV 10. The process S100 is executed by the control device 50 at a constant cycle.

In S101, the control device 50 calculates the OCV variation correction coefficient by the equation 1.

In S102, the control device 50 calculates the “OCV center duty” which is the center value of the dead zone of the OCV 10. The OCV center duty can be calculated by averaging the learning value of the duty corresponding to the upper end of the dead zone and the learning value of the duty corresponding to the lower end of the dead zone.

In S103, the control device 50 calculates the upper end duty and the lower end duty of the dead zone of the virtual OCV. The control device 50 calculates the value obtained by adding 1/2 of the virtual OCV dead band width to the OCV center duty calculated in S102 as the "virtual OCV dead band upper end duty", and calculates from the OCV center duty to 1/2 of the virtual OCV dead band width. Is calculated as the "virtual OCV dead zone lower end duty".

In S104, the control device 50 calculates the “virtual OCV holding duty learning value” by the equation 2.

In S105, the control device 50 calculates the basic control amount in the virtual OCV using the map data with the engine speed and the oil temperature as parameters. Here, the oil temperature, which is the temperature of the hydraulic oil, can be detected by the oil temperature sensor 63 provided in the hydraulic line connecting the oil pump 41 and the OCV 10.

In S106, the control device 50 calculates the "basic duty" in the virtual OCV based on the following equation 4.
Basic duty = virtual OCV holding duty learning value + basic control amount ・ ・ ・ Equation 4

In S107, the control device 50 determines whether or not the basic duty calculated in S106 is outside the dead zone of the virtual OCV. When the basic duty is outside the dead zone of the virtual OCV (S107: YES), the process shifts to S108. On the other hand, when the basic duty is within the dead zone of the virtual OCV (S107: NO), the process shifts to S120.

In S120, the control device 50 calculates the “virtual OCV dead zone control amount” based on the following equation 5.
Control amount in virtual OCV dead zone = basic duty-virtual OCV holding duty learning value ... Equation 5

In S121, the control device 50 converts the "virtual OCV dead zone control amount" into the "real OCV dead zone control amount" based on the following equation 6.
Control amount in the real OCV dead zone = Control amount in the virtual OCV dead zone x OCV variation correction coefficient ・ ・ ・ Equation 6

In S122, the control device 50 sets the “actual OCV dead zone control amount” calculated in S121 as the “control amount” based on the following equation 7.
Control amount = Control amount in the actual OCV dead zone ・ ・ ・ Equation 7

In S108, the control device 50 determines whether or not the basic duty calculated in S106 is larger than the virtual OCV dead zone upper end duty. When the basic duty is larger than the virtual OCV dead zone upper end duty (S108: YES), the process shifts to S109. On the other hand, when the basic duty is equal to or less than the virtual OCV dead zone upper end duty (S108: NO), the process shifts to S130.

In S109, the control device 50 calculates the “virtual OCV insensitive out-of-band control amount” based on the following equation 8.
Virtual OCV dead zone control amount = basic duty-Virtual OCV dead zone upper end duty ... Equation 8

In S110, the control device 50 converts the “virtual OCV insensitive out-of-band control amount” into the “real OCV insensitive out-of-band control amount” based on the following equation 9.
Real OCV insensitive out-of-band control amount = Virtual OCV insensitive out-of-band control amount x temperature correction coefficient ・ ・ ・ Equation 9

Here, since the displacement speed of the hydraulic actuator 30 is affected by the oil temperature, the "temperature correction coefficient" in the equation 9 is set according to the oil temperature of the hydraulic oil detected by the oil temperature sensor 63.

In S111, the control device 50 calculates the "virtual OCV dead zone control amount" based on the following equation 10.
Control amount in virtual OCV dead zone = virtual OCV dead zone upper end duty-virtual OCV holding duty learning value ... Equation 10

In S112, the control device 50 converts the “virtual OCV dead zone control amount” into the “real OCV dead zone control amount” according to the above equation 6.

In S113, the control device 50 calculates the "control amount" based on the following equation 11 by using the "actual OCV insensitive zone control amount" calculated in S110 and the "actual OCV insensitive zone control amount" calculated in S112. ..
Control amount = Control amount in the actual OCV dead zone + Control amount outside the actual OCV dead zone ... Equation 11

In S130, the control device 50 calculates the “virtual OCV insensitive out-of-band control amount” based on the following equation 12.
Virtual OCV dead zone control amount = basic duty-Virtual OCV dead zone lower end duty ・ ・ ・ Equation 12

In S131, the control device 50 converts the “virtual OCV insensitive out-of-band control amount” into the “real OCV insensitive out-of-band control amount” by the above equation 9.

In S132, the control device 50 calculates the “virtual OCV dead zone control amount” based on the following equation 13.
Control amount in virtual OCV dead zone = virtual OCV dead zone lower end duty-virtual OCV holding duty learning value ... Equation 13

In S133, the control device 50 converts the “virtual OCV dead zone control amount” into the “real OCV dead zone control amount” according to the above equation 6.

In S134, the control device 50 calculates the "control amount" based on the above equation 11 by using the "actual OCV insensitive zone control amount" calculated in S131 and the "actual OCV insensitive zone control amount" calculated in S133. ..

Next, the "identification of the dead zone, that is, the process related to learning" by the dead zone specifying unit 52 of the control device 50 will be specifically described.

The flowchart shown in FIG. 7 shows the process S200 related to the learning of the dead zone. The process S200 is executed by the control device 50 at a constant cycle.

In S201, the dead zone specifying unit 52 determines whether or not the engine speed is constant as a learning execution condition. When it is determined that the engine speed is constant (S201: YES), the process shifts to S202. On the other hand, when it is determined that the engine speed is not constant (S201: NO), the process exits S200.

It is necessary that the conditions are always the same during the execution of the process S200. In particular, factors that have a large effect on speed, such as oil pressure and cam torque, need to be in a steady state. Therefore, in the present embodiment, in S201, "the engine speed is constant" is set as an example of the condition.

In S202, the dead zone identification unit 52 inputs a duty instruction pattern to the OCV 10. Specifically, the dead zone identification unit 52 outputs an OCV drive duty as a “control signal” as shown in the upper part of FIG. 8 to the OCV 10. In this way, when the OCV drive duty (“duty instruction pattern”), which is a specific “control signal”, is output to the OCV 10, the OCV 10 operates and the phase of the hydraulic actuator 30 changes as shown in the lower part of FIG. ..

The dead zone specifying unit 52 stores in advance a "control signal" that is assumed to fall within or outside the dead zone as a "specific control signal", and in S202, the "specific control signal" is stored. Is output to OCV10.

In S203, the dead zone specifying unit 52 detects the “actual advance angle value” corresponding to the actual displacement angle of the camshaft 4 with respect to the crankshaft 3. Specifically, the dead zone identification unit 52 calculates the relative phase of the camshaft 4 with respect to the crankshaft 3 in the advance direction based on the signals from the crank angle sensor 61 and the cam angle sensor 62, thereby calculating the actual advance angle value. Is detected.

In S204, the dead zone identification unit 52 calculates the operating speed of the hydraulic actuator 30. Specifically, based on the actual advance angle value detected in S203, the speed is calculated for each specific OCV drive duty (“control signal”) of the duty instruction pattern input to the OCV 10. More specifically, as shown in FIG. 9, the dead zone specifying unit 52 calculates the speed for each specific OCV drive duty (d1 to d7: see FIG. 8). As shown in FIG. 9, the speeds s1 to s7 corresponding to each of the OCV drive duties d1 to d7 are calculated.

In S205, the dead zone specifying unit 52 selects speed points inside and outside the dead zone. Specifically, the speeds (s1 to s7) corresponding to each of the OCV drive duties (d1 to d7) calculated in S204 are selected as the speed points.

In S206, the dead zone identification unit 52 determines whether or not the speed point selected in S205 is equal to or less than the maximum speed point. Here, the "maximum speed" is the maximum value of the assumed operating speed of the hydraulic actuator 30, and for example, the hydraulic actuator 30 when "100" or "0" is output to the OCV 10 as the OCV drive duty. The speed of operation (st1, st2: see FIG. 10) corresponds to the "maximum speed". In the present embodiment, the dead zone identification unit 52 stores the "maximum speed" in advance.

When it is determined that the selected speed point is equal to or less than the maximum speed point (S206: YES), the process proceeds to S207. On the other hand, when it is determined that the selected speed point is larger than the maximum speed point (S206: NO), the process returns to S202. In this case, in S202, an OCV drive duty smaller than the OCV drive duty previously output for the OCV 10 is output to the OCV 10.

In S207, the dead zone specifying unit 52 calculates the upper and lower end duty of the dead zone based on the intersection of the approximate lines. Specifically, the duty corresponding to the intersection of the approximate line along the speed point in the dead zone and the approximate line along the speed point outside the dead zone selected in S205 is defined as the "upper end duty" or "lower end duty" of the dead zone.

For example, as shown in FIGS. 9 and 10, when the temperature of the hydraulic oil, that is, the oil temperature is higher than a predetermined value, the approximate line (straight line) Ls1 along the velocity points (s1, s2, s7) in the dead zone The duty corresponding to the intersection p1 with the approximate line (straight line) Ls2 along the velocity points (s3, s5) outside the dead zone on the advance angle side is defined as the "upper end duty" of the dead zone. Further, the duty corresponding to the intersection p2 of the approximate line Ls1 and the approximate line (straight line) Ls3 along the velocity points (s4, s6) outside the dead zone on the retard side is defined as the "lower end duty" of the dead zone.

In this way, the dead zone specifying unit 52 estimates the speed bending point (p1, p2), which is a sudden change part of the speed, based on the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10. This makes it possible to identify the dead zone by learning the upper and lower ends of the dead zone.

More specifically, the dead zone identification unit 52 approximates the measurement point (speed point) of the operation speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10 with a plurality of straight lines (approximate lines). The velocity bending point is estimated from the intersection of the straight lines.

After S207, the process exits S200.

The control unit 51 outputs a control signal to the OCV 10 and controls the operation of the hydraulic actuator 30 by executing S100 based on the dead zone specified (learned) by the dead zone specifying unit 52 in S200.

As shown in FIG. 10, when the straight line (approximate line) Lst1 along the speed point s3 and the maximum speed point st1 is used as an approximate line outside the dead zone, the dead zone upper end duty is erroneously calculated. Therefore, in the present embodiment, in S206, by determining whether or not the selected speed point is equal to or less than the maximum speed point, the approximate line outside the dead zone is correctly calculated, and the upper and lower end duty of the dead zone is erroneously calculated. Can be suppressed.

In this way, the dead zone identification unit 52 estimates the speed bending point based on the maximum value of the operating speed of the hydraulic actuator 30. As a result, as described above, it is possible to prevent the dead zone upper and lower end duties from being erroneously calculated.

As shown in FIG. 11, when the temperature of the hydraulic oil, that is, the oil temperature is lower than a predetermined value, the operating speed of the hydraulic actuator 30 in the dead zone becomes substantially 0 regardless of the OCV drive duty. In this case, since the approximate line (straight line) Ls1 along the velocity point in the dead zone becomes 0 (Ls1 = 0), it is not necessary to calculate and select the velocity point in the dead zone. Therefore, in the present embodiment, when the dead zone identification unit 52 determines that the hydraulic oil is at a low temperature based on, for example, the signal from the oil temperature sensor 63, the calculation and selection of the speed point in the dead zone is omitted. As a result, the load of processing related to learning of the dead zone can be reduced, and the processing can be speeded up.

In the present embodiment, in order to identify the dead zone by learning the upper end and the lower end of the dead zone by estimating the speed bending point which is a sudden change part of the operating speed of the hydraulic actuator 30, the hydraulic oil is as shown in FIG. The velocity bending point can be accurately estimated regardless of whether the temperature is high (solid line) or low temperature (dashed line), and the learning deviation between the upper and lower ends of the dead zone between the high temperature and low temperature of the hydraulic oil can be suppressed. As a result, the accuracy of dead zone learning can be improved.

Further, in the present embodiment, when the load of the direct injection pump operated by the rotation of the cam shaft 4 is large, the average cam torque acting on the rotor 32 of the hydraulic actuator 30 becomes small, and when the load of the direct injection pump is small, the rotor 32 The average cam torque acting on the engine increases. In the present embodiment, the average cam torque is as shown in FIG. 13 in order to identify the dead zone by learning the upper end and the lower end of the dead zone by estimating the speed bending point which is a sudden change part of the operating speed of the hydraulic actuator 30. Whether when is small (solid line) or when the average cam torque is large (dashed line), the velocity bending point can be estimated accurately, and the learning deviation between the upper and lower ends of the dead zone between when the average cam torque is small and when it is large can be suppressed. As a result, the accuracy of dead zone learning can be improved.

On the other hand, as shown in FIG. 14, in the comparative mode in which the velocity bending point is calculated based on the velocity threshold value, learning of the upper and lower ends of the dead zone when the hydraulic oil is high temperature (solid line) and low temperature (dashed line) is learned. There is a risk that the deviation will be large.

Further, as shown in FIG. 15, in the comparative mode in which the velocity bending point is calculated based on the velocity threshold value, the learning deviation between the upper and lower ends of the dead zone is different between when the average cam torque is small (solid line) and when it is large (dashed line). It may grow larger.

From the above, it can be said that the accuracy of the dead zone learning is higher in this embodiment than in the comparative embodiment regardless of the oil temperature of the hydraulic oil and the magnitude of the average cam torque.

In the present embodiment, the dead zone specifying unit 52 can learn the upper end and the lower end of the dead zone under different conditions regarding the oil temperature of the hydraulic oil, the magnitude of the average cam torque, and the like.

In the present embodiment, the dead zone identification unit 52 executes a process (S200) for identifying the dead zone before the control device 50 or the vehicle is shipped to the market.

As described above, <1> In the present embodiment, the control unit 51 controls the operation of the hydraulic actuator 30 by the control signal output to the OCV 10. The dead zone specifying unit 52 identifies a dead zone in the signal range in which the control signal is output, which is a region where the hydraulic actuator 30 does not respond to a change in the control signal or the response is low.

The dead zone identification unit 52 learns the upper and lower ends of the dead zone by estimating the speed bending point, which is a sudden change part of the speed, based on the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10. By doing so, the dead zone is identified.

The control unit 51 outputs a control signal to the OCV 10 based on the dead zone specified by the dead zone specifying unit 52, and controls the operation of the hydraulic actuator 30.

In the present embodiment, the dead zone specifying unit 52 estimates the speed bending point, which is a sudden change part of the speed, based on the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10, so that the hydraulic actuator The 30 dead zones can be identified in a short time.

That is, in the present embodiment, it is not necessary to actually measure a large number of duties in the sudden change in speed. Therefore, the number of actual measurements can be minimized, and the controllability of the valve timing adjusting device 2 can be improved at an early stage.

Further, since the dead zone is learned by estimating the velocity bending point, a velocity threshold value is not required. Since the threshold value is not defined by disturbances such as oil temperature, oil pressure, and cam torque change of hydraulic oil, the man-hours for conforming can be reduced.

<2> In the present embodiment, the dead zone identification unit 52 approximates the measurement point of the operation speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10 with a plurality of straight lines, and the intersection of the straight lines. The velocity bending point is estimated from. Since the estimation (learning) is performed by linear approximation, the number of test patterns can be reduced.

<3> In the present embodiment, the dead zone specifying unit 52 stores a control signal that is assumed to fall within or outside the dead zone as the specific control signal. Therefore, it is not necessary to determine whether the specific control signal output to the OCV 10 during the dead zone learning is inside the dead zone or outside the dead zone. Therefore, the processing related to the learning of the dead zone can be speeded up.

<4> In the present embodiment, the dead zone identification unit 52 estimates the speed bending point based on the maximum value of the operating speed of the hydraulic actuator 30. Therefore, erroneous learning at the upper and lower ends of the dead zone can be suppressed.

Further, in the <6> present embodiment, the dead zone specifying unit 52 can learn each of the upper end and the lower end of the dead zone under different conditions. Therefore, under various conditions, only the upper end of the dead zone or only the lower end of the dead zone can be learned. As a result, the conditional constraints for learning are reduced, so that learning opportunities can be increased.

<10> In the present embodiment, the dead zone identification unit 52 identifies the dead zone before the control device 50 is shipped to the market. Therefore, it is possible to prevent the control device 50 from appearing on the market without learning about the dead zone and reducing the output and emission effect of the vehicle. In addition, before shipping to the market, it is possible to sufficiently carry out learning of the dead zone without causing any inconvenience to the user. Therefore, the learning accuracy of the dead zone can be improved.

<11> The valve timing adjustment system 1 of the present embodiment includes the valve timing adjustment device 2 and the control device 50, and the control device 50 controls the valve timing adjustment device 2 to control the engine 5. The valve timing can be adjusted. As described above, the control device 50 can identify the dead zone of the hydraulic actuator 30 in a short time. Therefore, the controllability of the valve timing adjusting device 2 can be improved at an early stage.

(Second Embodiment)
Hereinafter, the control device according to the second embodiment will be described. In the second embodiment, the processing related to learning of the dead zone is different from that in the first embodiment.

In the present embodiment, as shown in FIG. 16, S207 of the processing S200 related to learning of the dead zone is different from that of the first embodiment. Since S201 to S206 are the same as those in the first embodiment, the description thereof will be omitted.

In S207, the dead zone specifying unit 52 identifies the dead zone by learning the upper and lower ends of the dead zone, and the control unit 51 further calculates the “maximum speed arrival duty” as in the first embodiment. Here, the "maximum speed reaching duty" means that the operating speed of the hydraulic actuator 30 reaches the maximum speed when the OCV drive duty as a control signal output to the OCV 10 is gradually increased or decreased. This is the OCV drive duty at the time of.

Specifically, the control unit 51 approximates the measurement point (velocity point) of the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10 with a plurality of straight lines, and the pressure is applied from the intersection of the straight lines. The maximum speed reaching point, which is the point where the operating speed of the actuator 30 is maximized, is estimated.

For example, as shown in FIG. 17, an approximate line (straight line) Ls2 along the velocity points (s3, s5) outside the dead zone on the advance angle side and an approximate line (straight line) Ls4 passing through the maximum velocity point st1 on the advance angle side. Let the intersection p3 of be the "maximum speed arrival point" on the advance angle side. Further, the intersection p4 of the approximate line (straight line) Ls3 along the velocity points (s4, s6) outside the dead zone on the retard angle side and the approximate line (straight line) Ls5 passing through the maximum velocity point st2 on the retard angle side is on the retard side. Let it be the "maximum speed arrival point".

The control unit 51 outputs a control signal to the OCV 10 based on the maximum speed arrival point estimated in S207, and controls the operation of the hydraulic actuator 30. Specifically, when the hydraulic actuator 30 is operated at the maximum speed on the advance side, the control unit 51 outputs a duty (control signal) corresponding to the maximum speed arrival point p3 on the advance side to the OCV 10. As a result, the power consumption of the OCV 10 when operating the hydraulic actuator 30 at the maximum speed on the advance side can be reduced. This is because the operating speed of the hydraulic actuator 30 does not become larger than the maximum speed st1 even if a duty larger than the duty corresponding to the maximum speed arrival point p3 is output to the OCV 10.

As described above, the <5> control unit 51 approximates the measurement points of the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10 with a plurality of straight lines, and the pressure is applied from the intersection of the straight lines. The maximum speed reaching point, which is the point where the operating speed of the actuator 30 is maximized, is estimated, and a control signal is output to the OCV 10 based on the estimated maximum speed reaching point to control the operation of the hydraulic actuator 30. Therefore, the power consumption of the OCV 10 when operating the hydraulic actuator 30 at the maximum speed can be reduced. Further, when a speed reduction request is made, it is possible to skip the maximum speed range and quickly reduce the duty.

(Third Embodiment)
Hereinafter, the control device according to the third embodiment will be described. In the third embodiment, the processing related to learning of the dead zone is different from that in the first embodiment.

The flowchart shown in FIG. 18 shows the process S300 related to the learning of the dead zone in the present embodiment. The process S300 is executed by the control device 50 at a constant cycle.

In S301, the dead zone specifying unit 52 determines, as a learning execution condition, whether or not the engine speed is equal to or higher than a predetermined value and the engine speed is constant. When it is determined that the engine speed is equal to or higher than a predetermined value and the engine speed is constant (S301: YES), the process proceeds to S302. On the other hand, when it is determined that "the engine speed is equal to or higher than a predetermined value and the engine speed is not constant" (S301: NO), the process exits S300.

In S302, the dead zone identification unit 52 inputs a duty instruction pattern to the OCV 10. Specifically, the dead zone identification unit 52 outputs a duty instruction pattern consisting of duty (d1, d2, d3) obtained by increasing the OCV drive duty by 1% from the holding duty as a specific "control signal" to the OCV 10. (See the upper part of FIG. 19).

In S303, the dead zone specifying unit 52 detects a "actual advance angle value" corresponding to the actual displacement angle of the camshaft 4 with respect to the crankshaft 3.

In S304, the dead zone identification unit 52 calculates the operating speed of the hydraulic actuator 30. Specifically, based on the actual advance angle value detected in S303, the speed is calculated for each specific OCV drive duty (“control signal”) of the duty instruction pattern input to the OCV 10.

In S305, the dead zone identification unit 52 calculates the speed change rate ΔV, which is the rate of change in the operating speed of the hydraulic actuator 30. Specifically, based on the speed calculated in S304, the speed change rate ΔV for each duty of the duty instruction pattern is calculated (see the lower part of FIG. 19).

In S306, the dead zone identification unit 52 determines whether or not the velocity change rate ΔV calculated in S305 is larger than the average of each ΔV. When it is determined that the rate change rate ΔV is larger than the average of each ΔV (S306: YES), the process proceeds to S307. On the other hand, when it is determined that the rate change rate ΔV is equal to or less than the average of each ΔV (S306: NO), the process returns to S306.

In S307, the dead zone specifying unit 52 reduces the interval between the test dutys, which are the duties of the duty instruction pattern (d4, d5), and calculates the speed change rate ΔV for each duty (see the lower part of FIG. 19).

In S308, the dead zone identification unit 52 determines whether or not the velocity change rate ΔV calculated in S307 is substantially the same as the average of ΔV. When it is determined that the rate change rate ΔV is substantially the same as the average of ΔV (S308: YES), the process proceeds to S309. On the other hand, when it is determined that the rate change rate ΔV is not substantially the same as the average of ΔV (S308: NO), the process returns to S307.

In S309, the dead zone specifying unit 52 can learn the upper end of the dead zone by storing the duty for which the speed change rate ΔV is calculated in S307 as the “upper end duty” of the dead zone. The duty for which the speed change rate ΔV is calculated in S307 corresponds to the speed bending point p1 which is a sudden change portion of the operating speed of the hydraulic actuator 30.

Further, the dead zone specifying unit 52 outputs a duty indicating pattern consisting of a duty obtained by reducing the OCV drive duty by 1% from the holding duty as a specific "control signal" in S302 to the OCV 10, and in S309, in S307. By storing the duty for which the speed change rate ΔV is calculated as the “lower end duty” of the dead zone, the lower end of the dead zone can be learned. The duty for which the speed change rate ΔV is calculated in S307 corresponds to the speed bending point p2, which is a sudden change portion of the operating speed of the hydraulic actuator 30.

As described above, the dead zone specifying unit 52 is a speed bending point (p1, p2) which is a sudden change part of the speed based on the rate of change ΔV of the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10. ), And the upper and lower ends of the dead zone can be learned to identify the dead zone.

As described above, <7> In the present embodiment, the dead zone identification unit 52 is a sudden change unit of the speed based on the rate of change of the operation speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10. The dead zone is specified by learning the upper and lower ends of the dead zone by estimating the velocity bending point.

In the present embodiment, the dead zone specifying unit 52 estimates the speed bending point, which is a sudden change part of the speed, based on the rate of change of the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10. As in the first embodiment, the dead zone of the hydraulic actuator 30 can be specified in a short time.

Further, in the present embodiment, since the dead zone is specified based on the rate of change in the operating speed of the hydraulic actuator 30, it is not necessary to define the speed threshold value, and water temperature, oil temperature, oil pressure, etc. are added as in the prior art. There is no need.

Further, since the dead zone is learned by estimating the velocity bending point, a velocity threshold value is not required. Since it is not necessary to define the threshold value in consideration of disturbances such as water temperature, oil temperature, oil pressure, and change in cam torque, the man-hours for conforming can be reduced. The velocity bending point is defined as a point at which the rate of change in velocity changes suddenly.

(Fourth Embodiment)
Hereinafter, the control device according to the fourth embodiment will be described. In the fourth embodiment, the process related to learning of the dead zone is different from that in the third embodiment.

The flowchart shown in FIG. 20 shows the process S400 related to the learning of the dead zone in the present embodiment. The process S400 is executed by the control device 50 at a constant cycle.

In S401, the dead zone specifying unit 52 determines whether or not the engine speed is equal to or higher than a predetermined value and the engine speed is constant as a learning execution condition. When it is determined that the engine speed is equal to or higher than a predetermined value and the engine speed is constant (S401: YES), the process shifts to S402. On the other hand, when it is determined that "the engine speed is equal to or higher than a predetermined value and the engine speed is not constant" (S401: NO), the process exits S400.

In S402, the dead zone identification unit 52 inputs a duty instruction pattern to the OCV 10. Specifically, the dead zone identification unit 52 increases or decreases the OCV drive duty from the holding duty by a predetermined amount as a specific "control signal" in at least a part of the output expected range of the "control signal" ( A duty instruction pattern consisting of d1 to d9) is output to the OCV 10 (see the upper part of FIG. 21).

In S403, the dead zone identification unit 52 detects the “actual advance angle value” corresponding to the actual displacement angle of the camshaft 4 with respect to the crankshaft 3.

In S404, the dead zone identification unit 52 calculates the operating speed of the hydraulic actuator 30. Specifically, based on the actual advance angle value detected in S403, the speed is calculated for each specific OCV drive duty (“control signal”) of the duty instruction pattern input to the OCV 10.

In S405, the dead zone identification unit 52 calculates the speed change rate ΔV, which is the rate of change in the operating speed of the hydraulic actuator 30. Specifically, based on the speed calculated in S404, the speed change rate ΔV is calculated in at least a part of the expected output range of the “control signal” (see the lower part of FIG. 21).

In S406, the dead zone identification unit 52 determines whether or not the velocity change rate ΔV calculated in S405 is larger than the average of ΔV. Specifically, the dead zone specifying unit 52 checks the magnitude relationship between the velocity change rate ΔV and the average of ΔV in the direction in which the duty increases from the holding duty, that is, in the direction in which the velocity change rate ΔV increases. , It is determined whether or not the velocity change rate ΔV is larger than the average of ΔV. Further, the dead zone specifying unit 52 checks the magnitude relationship between the speed change rate ΔV and the average of ΔV in the direction in which the duty decreases from the holding duty, that is, in the direction in which the speed change rate ΔV increases, and the speed change. It is determined whether or not the rate ΔV is larger than the average of ΔV. In this way, the dead zone identification unit 52 searches for a point (duty) that has changed from the place where the velocity change rate ΔV is constant (the average of ΔV).

When it is determined that the rate change rate ΔV is larger than the average of ΔV (S406: YES), the process shifts to S407. On the other hand, when it is determined that the rate change rate ΔV is equal to or less than the average of ΔV (S406: NO), the process returns to S406.

In S407, the dead zone specifying unit 52 calculates the “upper end duty” and the “lower end duty” of the dead zone. Specifically, in S406, the magnitude relationship between the speed change rate ΔV and the average of ΔV is checked from the holding duty in the direction of increasing duty, and it is determined that the speed change rate ΔV becomes larger than the average of ΔV. The duty at the time of this is calculated as the "upper end duty" of the dead zone. Further, in S406, the magnitude relationship between the speed change rate ΔV and the average of ΔV is checked from the holding duty in the direction of decreasing duty, and it is determined that the speed change rate ΔV becomes larger than the average of ΔV. The duty is calculated as the "bottom duty" of the dead zone.

The duty when it is determined in S406 that the speed change rate ΔV becomes larger than the average of ΔV corresponds to the speed bending point (p1, p2) which is a sudden change part of the operating speed of the hydraulic actuator 30.

As described above, the dead zone specifying unit 52 is a speed bending point (p1, p2) which is a sudden change part of the speed based on the rate of change ΔV of the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10. ), And the upper and lower ends of the dead zone can be learned to identify the dead zone.

As described above, <8> In the present embodiment, the dead zone identification unit 52 sets the rate of change in the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10 within the expected output range of the control signal. Calculate at least in part and estimate the velocity inflection point based on the calculated rate of change.

In the present embodiment, the dead zone specifying unit 52 estimates the speed bending point, which is a sudden change part of the speed, based on the rate of change of the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10. , The dead zone of the hydraulic actuator 30 can be specified in a short time as in the third embodiment.

(Fifth Embodiment)
Hereinafter, the control device according to the fifth embodiment will be described. In the fifth embodiment, the process related to learning of the dead zone is different from that in the fourth embodiment.

The flowchart shown in FIG. 22 shows the process S500 related to the learning of the dead zone in the present embodiment. The process S500 is executed by the control device 50 at a constant cycle.

In S501, the dead zone identification unit 52 inputs a duty instruction pattern to the OCV 10. Specifically, the dead zone specifying unit 52 increases or decreases the OCV drive duty by a predetermined amount from the holding duty as a specific "control signal" in the entire range of the output expected range of the "control signal" (d1 to 1). A duty instruction pattern consisting of d13) is output to the OCV 10 (see the upper part of FIG. 23).

In S502, the dead zone identification unit 52 detects the “actual advance angle value” corresponding to the actual displacement angle of the camshaft 4 with respect to the crankshaft 3.

In S503, the dead zone identification unit 52 calculates the operating speed of the hydraulic actuator 30. Specifically, based on the actual advance angle value detected in S502, the speed is calculated for each specific OCV drive duty (“control signal”) of the duty instruction pattern input to the OCV 10.

In S504, the dead zone identification unit 52 calculates the speed change rate ΔV, which is the rate of change in the operating speed of the hydraulic actuator 30. Specifically, based on the speed calculated in S503, the speed change rate ΔV is calculated over the entire expected output range of the “control signal” (see the lower part of FIG. 23).

In S505, the dead zone identification unit 52 determines whether or not the velocity change rate ΔV calculated in S504 is larger than the average of ΔV. Specifically, the dead zone specifying unit 52 checks the magnitude relationship between the velocity change rate ΔV and the average of ΔV in the direction in which the duty increases from the holding duty, that is, in the direction in which the velocity change rate ΔV increases. , It is determined whether or not the velocity change rate ΔV is larger than the average of ΔV. Further, the dead zone specifying unit 52 checks the magnitude relationship between the speed change rate ΔV and the average of ΔV in the direction in which the duty decreases from the holding duty, that is, in the direction in which the speed change rate ΔV increases, and the speed change. It is determined whether or not the rate ΔV is larger than the average of ΔV.

Further, the dead zone identification unit 52 has a magnitude of the average of the speed change rates ΔV and ΔV in the direction in which the duty decreases from the upper limit of the output assumed range of the “control signal”, that is, in the direction in which the speed change rate ΔV increases. The relationship is checked to determine whether the rate of change in velocity ΔV is greater than the average of ΔV. Further, the dead zone identification unit 52 has a magnitude of the average of the speed change rates ΔV and ΔV in the direction in which the duty increases from the lower limit of the output assumed range of the “control signal”, that is, in the direction in which the speed change rate ΔV increases. The relationship is checked to determine whether the rate of change in velocity ΔV is greater than the average of ΔV. In this way, the dead zone identification unit 52 searches for a point (duty) that has changed from the place where the velocity change rate ΔV is constant (the average of ΔV).

When it is determined that the rate change rate ΔV is larger than the average of ΔV (S505: YES), the process shifts to S506. On the other hand, when it is determined that the rate change rate ΔV is equal to or less than the average of ΔV (S505: NO), the process returns to S505.

In S506, the dead zone specifying unit 52 calculates the “upper end duty” and the “lower end duty” of the dead zone, and estimates the “maximum speed arrival duty”. Specifically, in S505, the magnitude relationship between the speed change rate ΔV and the average of ΔV is checked in the direction of increasing duty from the holding duty, and it is determined that the speed change rate ΔV becomes larger than the average of ΔV. The duty at the time of this is calculated as the "upper end duty" of the dead zone. Further, in S505, the magnitude relationship between the speed change rate ΔV and the average of ΔV is checked from the holding duty in the direction of decreasing duty, and it is determined that the speed change rate ΔV becomes larger than the average of ΔV. The duty is calculated as the "bottom duty" of the dead zone.

Further, in S505, the magnitude relationship between the speed change rate ΔV and the average of ΔV is checked from the upper limit of the output assumed range of the “control signal” toward the direction in which the duty decreases, and the speed change rate ΔV is ΔV. The duty when it is judged to be larger than the average is estimated as the "maximum speed arrival duty" on the advance side. Further, in S505, the magnitude relationship between the speed change rate ΔV and the average of ΔV is checked from the lower limit of the output assumed range of the “control signal” toward the direction in which the duty increases, and the speed change rate ΔV is ΔV. The duty when it is judged to be larger than the average is estimated as the "maximum speed arrival duty" on the retard side.

The "maximum speed arrival duty" on the advance angle side estimated in S506 corresponds to the maximum speed arrival point (p3) on the advance angle side. Further, the "maximum speed arrival duty" on the retard side estimated in S506 corresponds to the maximum speed arrival point (p4) on the retard side.

The control unit 51 outputs a control signal to the OCV 10 based on the maximum speed arrival point estimated in S506, and controls the operation of the hydraulic actuator 30. Specifically, when the hydraulic actuator 30 is operated at the maximum speed on the advance side, the control unit 51 outputs a duty (control signal) corresponding to the maximum speed arrival point p3 on the advance side to the OCV 10. As a result, the power consumption of the OCV 10 when operating the hydraulic actuator 30 at the maximum speed on the advance side can be reduced.

As described above, <9> In the present embodiment, the control unit 51 operates the hydraulic actuator 30 based on the rate of change in the operating speed of the hydraulic actuator 30 when a specific control signal is output to the OCV 10. The maximum speed arrival point, which is the point where the speed becomes maximum, is estimated, and a control signal is output to the OCV 10 based on the estimated maximum speed arrival point to control the operation of the hydraulic actuator 30.

Therefore, the power consumption of the OCV 10 when operating the hydraulic actuator 30 at the maximum speed can be reduced. Further, when a speed reduction request is made, it is possible to skip the maximum speed range and quickly reduce the duty.

Further, in the present embodiment, the speed change rate ΔV is calculated, the upper and lower ends of the dead zone are calculated, and the maximum speed arrival point is estimated in the entire range of the expected output of the “control signal”, so that the controllability is improved.

(Other embodiments)
In S406 and S505 of the fourth and fifth embodiments described above, the dead zone identification unit 52 has speed change rates ΔV and ΔV in the direction in which the duty increases or decreases from the holding duty, that is, in the direction in which the speed change rate ΔV increases. An example of determining whether or not the rate of change in velocity ΔV is larger than the average of ΔV is shown by checking the magnitude relationship with the average of. On the other hand, in another embodiment, the dead zone identification unit 52 has a duty in a direction in which the duty decreases from the duty in the outer range on the advance side of the dead zone, or a duty in the outer range on the retard side of the dead zone. The magnitude relationship between the velocity change rate ΔV and the average of ΔV is checked in the increasing direction, that is, in the direction in which the velocity change rate ΔV decreases, and it is determined whether or not the velocity change rate ΔV is smaller than the average of ΔV. You may do it.

Further, in S505 of the fifth embodiment described above, the dead zone identification unit 52 starts from the direction in which the duty decreases from the upper limit value of the expected output range of the "control signal" or from the lower limit value of the expected output range of the "control signal". The magnitude relationship between the velocity change rate ΔV and the average of ΔV is checked in the direction in which the duty increases, that is, in the direction in which the velocity change rate ΔV increases, and whether or not the velocity change rate ΔV becomes larger than the average of ΔV. An example of determining whether or not is shown. On the other hand, in another embodiment, the dead zone identification unit 52 checks the magnitude relationship between the speed change rate ΔV and the average of ΔV in the direction in which the speed change rate ΔV decreases, and the speed change rate ΔV becomes It may be determined whether or not it is smaller than the average of ΔV.

Further, in another embodiment, the dead zone identification unit 52 may execute a process of identifying the dead zone after the control device 50 or the vehicle is shipped to the market, that is, while the vehicle is traveling.

In another embodiment, the valve timing adjustment system may adjust the valve timing of the exhaust valve of the internal combustion engine.

Further, in another embodiment, for example, a hydraulic actuator may be used as an actuator for displaced the camshaft in the axial direction, and an adjusting device including the hydraulic actuator and a control valve may be used as a device for adjusting the valve lift of the internal combustion engine. Good.

As described above, the present disclosure is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof.

2 Valve timing adjustment device (adjustment device), 10 OCV (control valve), 30 hydraulic actuator, 50 control device, 51 control unit, 52 dead zone identification unit

Claims (11)

A control device (50) that controls an adjusting device (2) including a hydraulic actuator (30) that operates by supplying or discharging hydraulic oil and a control valve (10) that controls the supply or discharge of hydraulic oil to the hydraulic actuator. And
A control unit (51) that controls the operation of the hydraulic actuator by a control signal output to the control valve, and
A dead zone specifying unit (52) for identifying a dead zone, which is a region in which the hydraulic actuator does not respond to a change in the control signal or has low responsiveness in the signal range from which the control signal is output, is provided.
The dead zone specifying portion has an upper end and a lower end of the dead zone by estimating a speed bending point which is a sudden change portion of the speed based on the operating speed of the hydraulic actuator when a specific control signal is output to the control valve. Identify the dead zone by learning
The control unit is a control device that outputs a control signal to the control valve and controls the operation of the hydraulic actuator based on the dead zone specified by the dead zone specifying unit. The dead zone specifying unit approximates the measurement point of the operating speed of the hydraulic actuator when a specific control signal is output to the control valve with a plurality of straight lines, and estimates the speed bending point from the intersection of the straight lines. The control device according to claim 1. The control device according to claim 1 or 2, wherein the dead zone specifying unit stores a control signal that is assumed to fall within or outside the dead zone as the specific control signal. The control device according to any one of claims 1 to 3, wherein the dead zone specifying portion estimates the speed bending point based on the maximum value of the operating speed of the hydraulic actuator. The control unit approximates the measurement points of the operating speed of the hydraulic actuator when a specific control signal is output to the control valve with a plurality of straight lines, and the operating speed of the hydraulic actuator is determined from the intersection of the straight lines. Any one of claims 1 to 4 that estimates the maximum speed arrival point, which is the maximum point, outputs a control signal to the control valve based on the estimated maximum speed arrival point, and controls the operation of the hydraulic actuator. The control device according to the section. The control device according to any one of claims 1 to 5, wherein the dead zone specifying unit can learn each of the upper end and the lower end of the dead zone under different conditions. A control device (50) that controls an adjusting device (2) including a hydraulic actuator (30) that operates by supplying or discharging hydraulic oil and a control valve (10) that controls the supply or discharge of hydraulic oil to the hydraulic actuator. And
A control unit (51) that controls the operation of the hydraulic actuator by a control signal output to the control valve, and
A dead zone specifying unit (52) for identifying a dead zone, which is a region in which the hydraulic actuator does not respond to a change in the control signal or has low responsiveness in the signal range from which the control signal is output, is provided.
The dead zone specifying portion determines the speed bending point, which is a sudden change portion of the speed, based on the rate of change of the operating speed of the hydraulic actuator when a specific control signal is output to the control valve. Identify the dead zone by learning the top and bottom,
The control unit is a control device that outputs a control signal to the control valve and controls the operation of the hydraulic actuator based on the dead zone specified by the dead zone specifying unit. The dead zone identification unit calculates the rate of change in the operating speed of the hydraulic actuator when a specific control signal is output to the control valve in at least a part of the expected output range of the control signal, and uses the calculated rate of change as the calculated rate of change. The control device according to claim 7, wherein the speed bending point is estimated based on the above. The control unit reaches the maximum speed at which the operating speed of the hydraulic actuator becomes maximum based on the rate of change of the operating speed of the hydraulic actuator when a specific control signal is output to the control valve. The control device according to claim 7 or 8, wherein a control signal is output to the control valve based on the estimated maximum speed arrival point to control the operation of the hydraulic actuator. The control device according to any one of claims 1 to 9, wherein the dead zone identification unit identifies the dead zone before the control device is shipped to the market. With the adjusting device (2)
The control device (50) according to any one of claims 1 to 10 is provided.
A valve timing adjustment system (1) capable of adjusting the valve timing of the internal combustion engine (5) by controlling the adjustment device with the control device.

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