JP2009268193A - Device for controlling electric motor - Google Patents

Abstract

An electric motor control apparatus capable of suppressing an excessive increase in temperature of an electric motor with a simple control structure.
The apparatus controls the operation position of the electric motor through the operation control of the electric motor based on the duty signal Ds. The relationship between the estimated value Pi for the amount of current supplied to the electric motor and the duty signal Ds is stored, and the estimated value Pi is calculated based on the duty signal Ds from the relationship, and according to the transition of the estimated value Pi. The execution mode of the operation control of the electric motor is changed. As the above relationship, a first relational expression and a second relational expression determined by a linear function having the duty signal Ds as a variable are stored. As these relational expressions, relational expressions are stored in which the deviation directions of the estimated values Pi based on the actual value (actual value Pr) of the supplied current amount are opposite to each other.
[Selection] Figure 5

Description

  The present invention relates to a control device that controls the operating position of an electric motor.

  The internal combustion engine is provided with various operating mechanisms such as a variable valve mechanism for changing the valve characteristics (valve timing or valve valve operating angle) of the engine valve, and for changing the operating state of the operating mechanism. As an operation source, an electric motor (for example, an electric rotating machine) is frequently used. Such a control device for controlling the operating position of the electric motor includes an electronic control unit including a central processing unit (CPU) and a memory (ROM, RAM), and the operation command value is calculated by the electronic control unit. At the same time, a current corresponding to the operation command value is supplied to the electric motor to control the operation position of the electric motor.

  In the above control device, when the operation of the electric motor is repeated in a state where the supply current is large due to frequent changes in the operation state of the operation mechanism, the temperature of the electric motor rises excessively and the reliability of the electric motor increases. There is a risk of lowering. Therefore, the following apparatus has been proposed as an apparatus for avoiding such inconvenience. That is, the electronic control unit storing the relationship between the index value and the operation command value for the amount of change (temperature change amount) per unit period of the temperature of the electric motor, from the above relationship based on the operation command value at that time. The index value of the temperature change amount is calculated, and the control mode of the electric motor is changed according to the transition of the index value. Specifically, for example, the operation control of the electric motor is performed so that the motor current is reduced when the average value of the index value of the temperature change amount is equal to or greater than a predetermined threshold when the average value is more than a predetermined threshold. Is executed.

As an apparatus for calculating a specific value from the relationship stored in the electronic control unit in this way, an apparatus described in Patent Document 1 is known. In this apparatus, a two-dimensional calculation map that defines the relationship between calculation parameters and calculation values is stored in the electronic control unit. Then, a calculated value is calculated from the calculation map based on the calculation parameter at that time. The above relationship is such that the relationship between a large number of set calculation parameters and the calculated values corresponding to the calculated parameters is not a proportional relationship, and the actual calculated parameters (actual values) are stored in the calculation map. If the value is different from the stored value (stored value), the calculated value is calculated through an interpolation method based on two stored values sandwiching the actual value.
JP-A-9-56013

  Normally, when a calculated value is calculated through an interpolation method, there is an error between the calculated value and the value appropriate for the situation at that time, compared to when the value stored in the calculation map is calculated as the calculated value. It is likely to occur. As a technique for suppressing the error to be small in an apparatus using such an interpolation method, it is conceivable to narrow the interval of calculation parameters stored in the calculation map. However, if such a method is adopted, the error can be reduced, but it is not preferable because a large amount of data needs to be stored and the storage capacity of the electronic control unit increases. In general, the interpolation method is a calculation method in which the calculation load of the electronic control unit is likely to increase. Therefore, if the interpolation method is adopted, this also causes an increase in the calculation load, which is also not preferable. As described above, the control device is likely to have a complicated control structure for suppressing an excessive increase in the temperature of the electric motor, and there is room for improvement in this respect.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electric motor control device capable of suppressing an excessive increase in the temperature of the electric motor with a simple control structure.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
According to the first aspect of the present invention, control means for controlling the operation position of the electric motor through operation control of the electric motor based on the operation command value, and estimation of the index value of the change amount per unit period of the temperature of the electric motor. Storage means for storing the relationship between the value and the operation command value; and calculating the estimated value from the relationship based on the operation command value, and controlling the operation of the electric motor based on the transition of the calculated estimated value. In the control device for an electric motor comprising a changing means for changing the execution mode, the relation is composed of a plurality of relational expressions determined by a linear function having the operation command value as a variable, and the relational expressions are set of the operation command value. It consists of relational expressions set separately for each range obtained by dividing the possible range into a plurality of ranges, and the deviation direction of the estimated value based on the actual value for the index value is The first relational expression is opposite and be comprised of a second relational expression to have as its gist.

  In a control device that controls the operating position of an electric motor, a larger amount of current is supplied to the electric motor as the speed of change in the operating position increases and as the amount of change in the operating position increases. The temperature rises easily. In the above configuration, in such a situation where the operating position of the electric motor changes, the operation command value changes greatly, so that the value near the minimum value to the value near the maximum value in the settable range. To change.

  In the above configuration, the relationship used for calculating the estimated value for the index value of the change amount per unit period of the temperature of the electric motor is different from the relationship between the actual value (actual value) of the index value and the operation command value. Since the relational expression determined by the linear function is stored, the error of the estimated value calculated from the relational expression becomes large. However, according to the above configuration, when the estimated value is obtained in the process in which the operation command value greatly changes and the transition is grasped, an error caused by calculation through the first relational expression (a value obtained by subtracting the actual value from the estimated value) It is possible to cancel out a part of the influence of the error and a part of the influence of the error due to the calculation through the second relational expression. Therefore, when there is a concern about an excessive temperature rise of the electric motor because the operation command value has changed greatly, it is possible to properly grasp the transition of the estimated value and thus the temperature of the electric motor. The operation control of the electric motor can be appropriately executed according to the temperature.

  In addition, according to the above configuration, since the estimated value is calculated through an operation based on a relational expression determined by a linear function, the estimated value is stored in the storage unit in comparison with a configuration in which the estimated value is calculated through an operation based on an operation map. Data capacity can be reduced. Furthermore, since the estimated value can be calculated without using an interpolation method, the calculation load for the calculation can be reduced.

Therefore, an excessive increase in the temperature of the electric motor can be suppressed with a simple control structure.
According to claim 2, two relational expressions determined by a linear function having an operation command value as a variable are set as the relation, and the first relational expression and the second relational expression are set as the relational expressions. , And the configuration can be adopted.

  According to a third aspect of the present invention, in the electric motor control device according to the first or second aspect, the plurality of relational expressions are values obtained by subtracting estimated values stored in the relational expressions from the actual values. The gist of the relational expression is an average of “0”.

  According to the above configuration, when the estimated value is obtained and the transition is grasped in the process in which the operation command value greatly changes, an error caused by calculation through each relational expression (specifically, the actual value is subtracted from the estimated value). Most of the influence of the (value) can be canceled out by the influence of the error in the deviation direction, and the influence of the estimated value error can be suppressed to a very small level.

The gist of the invention according to claim 4 is the electric motor control device according to any one of claims 1 to 3, wherein the index value is an amount of current supplied to the electric motor.
According to the above configuration, the electric motor is based on the transition of the supply current amount having a high correlation with the temperature of the electric motor, such that the temperature of the electric motor is likely to increase as the amount of current supplied to the electric motor increases. It becomes possible to execute the operation control, and it is possible to accurately suppress an excessive increase in the temperature of the electric motor.

  According to a fifth aspect of the present invention, in the electric motor control device according to the fourth aspect, the changing means is configured to control the electric motor based on an average value in a predetermined period nearest to an estimated value of the supply current amount. The gist is to change the execution mode of the operation control.

  According to the above configuration, the temperature of the electric motor can be properly grasped from the transition of the amount of current supplied to the electric motor in the most recent predetermined period, and the operation control of the electric motor is appropriately executed based on the temperature. be able to.

  The configuration of the invention according to any one of claims 1 to 5 is applicable to an internal combustion engine provided with a variable valve mechanism for changing the valve characteristic of an engine valve as in claim 6. An electric rotating machine used as an operating source of the variable valve mechanism is employed as the electric motor, and can be realized in a control device in which an operation command value is calculated by the control means in accordance with the operating state of the internal combustion engine.

  In the configuration described in claim 6, the valve characteristic is a valve timing or a valve working angle of the engine valve. Furthermore, in the configuration according to claim 6, the variable valve mechanism includes a mechanism for changing the valve timing of the engine valve (intake valve or exhaust valve) and a mechanism for changing the valve valve working angle of the engine valve. .

Hereinafter, an embodiment in which a control device for an electric motor according to the present invention is embodied will be described.
FIG. 1 shows a cross-sectional structure around a cylinder head of an internal combustion engine on which a control device according to this embodiment is mounted.

  As shown in FIG. 1, a combustion chamber 14 is defined in the internal combustion engine 10 by a cylinder head 11, a cylinder block 12, and a piston 13, and an intake passage 15 and an exhaust passage 16 are formed in the combustion chamber 14. Is connected. The combustion chamber 14 and the intake passage 15 are communicated and blocked by the opening / closing operation of the intake valve 17, and the combustion chamber 14 and the exhaust passage 16 are communicated and blocked by the opening / closing operation of the exhaust valve 18.

  The cylinder head 11 is provided with an intake camshaft 19 for driving the intake valve 17 and an exhaust camshaft 20 for driving the exhaust valve 18. The intake camshaft 19 and the exhaust camshaft 20 are rotated by transmission of rotation from a crankshaft (not shown) of the internal combustion engine 10. The intake camshaft 19 is provided with an intake cam 19a, and the exhaust camshaft 20 is provided with an exhaust cam 20a. Then, the intake valve 17 is opened and closed through integral rotation of the intake camshaft 19 and the intake cam 19a, and the exhaust valve 18 is opened and closed through integral rotation of the exhaust camshaft 20 and the exhaust cam 20a.

  Further, between the intake valve 17 and the intake cam 19a, the valve characteristics of the intake valve 17 (specifically, the maximum lift amount and the valve operating angle (period from the valve opening timing to the valve closing timing)) are variable. A variable valve mechanism 21 is provided. The operation control of the variable valve mechanism 21 is executed so that, for example, the maximum lift amount and the valve operating angle increase as the engine operation state that requires a larger amount of intake air is achieved. This is because as the maximum lift amount and valve operating angle of the intake valve 17 are increased, the intake of air from the intake passage 15 to the combustion chamber 14 is performed more efficiently, and the above-described requirements regarding the intake air amount can be satisfied. It is.

Next, the structure of the variable valve mechanism 21 will be described.
The variable valve mechanism 21 includes a rocker shaft 22 and a control shaft 23 that extend parallel to the intake camshaft 19, and an input arm 24 and an output arm 25 that swing about the axes of the shafts 22 and 23. Yes. When the input arm 24 is swung by being pushed by the rotating intake cam 19a, the output arm 25 is swung accordingly.

  The input arm 24 is urged toward the intake cam 19a by a spring 26 so as to be pressed against the intake cam 19a. A rocker arm 27 is provided between the intake valve 17 and the output arm 25, a base end portion of the rocker arm 27 is supported by a lash adjuster 28, and a distal end portion is in contact with the intake valve 17. Further, the rocker arm 27 is urged toward the output arm 25 by the valve spring 29 of the intake valve 17 and is pressed against the output arm 25. When the input arm 24 swings with the output arm 25 as the intake cam 19a rotates, the swing of the output arm 25 is transmitted to the intake valve 17 via the rocker arm 27, and the intake valve 17 is lifted. The

  In the variable valve mechanism 21, the rocker shaft 22 is formed in a pipe shape, and the control shaft 23 is disposed inside the rocker shaft 22 so as to be movable in the axial direction. The variable valve mechanism 21 has a structure capable of changing the relative position of the input arm 24 and the output arm 25 in the swinging direction by changing the axial position of the control shaft 23 with respect to the rocker shaft 22. Then, by changing the relative position of the input arm 24 and the output arm 25 in the swing direction, the maximum lift of the intake valve 17 when the output arm 25 swings with the rotation of the intake cam 19a. The amount and valve working angle are changed. Specifically, as the input arm 24 and the output arm 25 are brought closer to each other in the swing direction, the maximum lift amount and the valve operating angle of the intake valve 17 become smaller.

  Next, a drive mechanism for displacing the control shaft 23 in the axial direction to drive the variable valve mechanism 21 and a control device for controlling the drive state of the mechanism will be described with reference to FIG.

  As shown in FIG. 2, a brushless motor 30 is connected to a base end portion (right end portion in the drawing) of the control shaft 23 via a conversion mechanism 31. The conversion mechanism 31 is for converting the rotational motion of the brushless motor 30 into a linear motion in the axial direction of the control shaft 23. The control shaft 23 is displaced in the axial direction through rotational driving within a predetermined rotational angle range of the brushless motor 30 (for example, a rotational angle range corresponding to 10 rotations (0 to 3600 °)), and a variable valve mechanism. 21 is activated.

  Incidentally, when the brushless motor 30 is rotated in the forward direction, the control shaft 23 is displaced to the tip side, and the relative positions of the input arm 24 and the output arm 25 in the swing direction are changed so as to approach each other. On the other hand, when the brushless motor 30 is rotated in the reverse direction, the control shaft 23 is displaced to the proximal end side, and the relative positions of the input arm 24 and the output arm 25 in the swing direction are changed so as to be separated from each other.

  As the brushless motor 30, a 4-pole 6-winding motor having three-phase windings is employed. The brushless motor 30 is driven through switching of a phase for supplying power (an energized phase). Specifically, six switchable energization patterns are set for the brushless motor 30, and one of these energization patterns is selectively set when controlling the drive of the brushless motor 30. Energization of the windings of each phase of the brushless motor 30 is performed.

  The apparatus according to the present embodiment includes an electronic control unit 32 that executes various engine controls such as operation control of the brushless motor 30. The electronic control unit 32 includes a central processing unit (CPU) that executes various arithmetic processes, a memory (ROM) that stores programs and data necessary for the arithmetic, and a memory that temporarily stores arithmetic results of the CPU. (RAM), input / output ports for inputting / outputting signals to / from the outside, and the like. In the present embodiment, the electronic control unit 32 functions as a storage unit.

  Various sensors are connected to the input port of the electronic control unit 32. Specifically, for example, a position sensor 33 for detecting the operating position (actual rotation angle MA) of the brushless motor 30, an accelerator position sensor 34 for detecting the depression amount of the accelerator pedal, and the crankshaft of the internal combustion engine 10 A rotational speed sensor 35 and the like for detecting the rotational speed (engine rotational speed) are connected. A drive circuit for the brushless motor 30 is connected to the output port of the electronic control unit 32.

Next, the operation control of the brushless motor 30 will be specifically described.
FIG. 3 is a flowchart showing an execution procedure of the processing (operation control processing) related to the operation control. The series of processes shown in the figure is executed by the electronic control unit 32 as a process for each predetermined cycle. In the present embodiment, this operation control process functions as a control means.

  As shown in FIG. 3, in this process, first, a control target value (target rotation angle TMA) for the rotation angle of the brushless motor 30 is calculated based on the depression amount of the accelerator pedal and the engine rotation speed (step S10). . Thereafter, a deviation between the target rotation angle TMA and the actual rotation angle (actual rotation angle MA) detected by the position sensor 33 is obtained, and a duty signal Ds as an operation command value is calculated based on the deviation. (Step S20). The duty signal Ds is a signal that defines a ratio (duty ratio) between a time during which a current is supplied to the brushless motor 30 and a time during which the same current is not supplied in a very short predetermined unit time. As the ratio increases, the amount of current supplied to the brushless motor 30 increases. Then, the amount of current supplied to each phase winding of the brushless motor 30 is adjusted according to the duty signal Ds (step S30).

  Through such processing, the rotational torque of the brushless motor 30 is adjusted to match the operating state of the internal combustion engine 10. Incidentally, when the target rotation angle TMA and the actual rotation angle MA coincide with each other, the rotation angle of the brushless motor 30 is maintained at the current angle with respect to each winding corresponding to the energization pattern set at this time. A predetermined amount of power that can be supplied is supplied.

  Here, as the amount of current supplied to the brushless motor 30 increases, the amount of heat generated in the built-in coil or the like increases, so the temperature of the brushless motor 30 tends to increase. Therefore, when the operation of the brushless motor 30 is repeated in a state where the supply current is large due to frequent changes in the operating state of the internal combustion engine 10, the temperature of the brushless motor 30 rises excessively and the reliability of the brushless motor 30 increases. There is a risk of lowering.

  Based on this point, in the present embodiment, the current supply amount to the brushless motor 30 is estimated based on the duty signal Ds, and the brushless motor 30 is controlled according to the transition of the estimated supply current amount. The mode is changed. Thereby, the operation control of the brushless motor 30 is executed according to the transition of the supply current amount, and an excessive increase in the temperature of the brushless motor 30 is accurately suppressed. In the present embodiment, the amount of current supplied to the brushless motor 30 is used as an index value of the amount of change per unit period of the temperature of the brushless motor 30.

Hereinafter, the process (change process) which changes the control aspect of the brushless motor 30 in that way is demonstrated concretely.
FIG. 4 is a flowchart showing the execution procedure of the change process. The series of processes shown in the figure is a process executed as a process for calculating the duty signal Ds in the operation control process described above (the process in step S20 in FIG. 3). In the present embodiment, this changing process functions as a changing means.

  As shown in FIG. 4, in this process, first, an estimated value Pi for the amount of current supplied to the brushless motor 30 is calculated based on the duty signal Ds calculated in the previous execution of this process (step S21). In the present embodiment, an arithmetic expression used to calculate the estimated value Pi is stored in the memory of the electronic control unit 32, and the estimated value Pi is calculated based on the arithmetic expression. Hereinafter, this arithmetic expression will be described in detail.

  FIG. 5 shows the relationship between the duty signal Ds and the amount of current supplied to the brushless motor 30. In FIG. 5, the solid line indicates the relationship between the duty signal Ds and the supply current amount (the estimated value Pi) calculated from the arithmetic expression, and the alternate long and short dash line indicates the duty signal Ds and the actual supply current amount (actual value). The relationship with Pr) is shown.

  As an arithmetic expression used to calculate the estimated value Pi, two relational expressions determined by a linear function having the duty signal Ds as a variable are set. As the relational expressions, as shown by the solid line in FIG. 5, the settable range of the duty signal Ds is divided into two (the range RA on the side where the duty signal Ds is smaller) corresponding to the first relational expression (Pi = A × Ds + b) and a second relational expression (Pi = c × Ds + d) corresponding to the other (range RB on the side where the duty signal Ds is large) are set. Note that “a” and “b” in the first relational expression and “c” and “d” in the second relational expression are both predetermined constants, which are obtained and stored in advance based on experimental results and the like. Has been.

  Here, as indicated by the alternate long and short dash line in FIG. 5, the duty ratio becomes larger as the duty signal Ds becomes a larger value. Therefore, the actual supply current amount (actual value Pr) to the brushless motor 30 is increased. Will increase. The relationship between the duty signal Ds and the actual value Pr is not a proportional relationship, but a relationship in which the change rate of the actual value Pr gradually decreases when the duty signal Ds is changed to a large value at a constant speed. ing.

  In view of this point, in the present embodiment, as the first relational expression and the second relational expression, a relational expression in which the deviation directions of the estimated value Pi with respect to the actual value Pr are opposite to each other is set. Yes. Specifically, in the range RA, the first difference is set such that the difference ΔP (= Pr−Pi) between the actual value Pr and the estimated value Pi in the range RAa where the duty signal Ds is smaller than the predetermined value α is a negative value. A relational expression is set, and the second relational expression is set so that the difference ΔP in the range RB becomes a positive value. In the range RAb in which the duty signal Ds is greater than the predetermined value α in the range RA, the difference ΔP (= Pr−Pi) between the actual value Pr and the estimated value Pi is a positive value. One relational expression is set.

  Moreover, in the present embodiment, as the first relational expression and the second relational expression, the average of the difference ΔP between the estimated value Pi and the actual value Pr stored in these relational expressions is “0”. A relational expression is set. Specifically, in the graph shown in FIG. 5, the difference ΔP among the first relational expression, the second relational expression, and the part (the part shown by hatching in FIG. 5) partitioned by the actual value Pr is negative. The first relational expression and the second relational expression are set so that the area S1 of the portion where the value becomes the same as the area S2 of the portion where the difference ΔP becomes a positive value.

  Then, after the estimated value Pi is calculated from the first relational expression and the second relational expression (step S21 in FIG. 4), the average value of the estimated value Pi in the most recent predetermined period (for example, several seconds). Pave is calculated (step S22). This average value Pave is used as a value for grasping the temperature of the brushless motor 30.

  Thereafter, it is determined whether or not this average value Pave is smaller than a predetermined value H (step S23). The predetermined value H is a value that can appropriately determine whether or not the temperature of the brushless motor 30 is likely to be excessively high, and is obtained and stored in advance based on experimental results. Yes.

  When the average value Piave is smaller than the predetermined value H (step S23: YES), the temperature of the brushless motor 30 is not likely to become excessively high at this time, and the first calculation is performed as the duty signal Ds calculation mode. A mode is selected (step S24). In this case, based on the deviation between the target rotation angle TMA and the actual rotation angle MA, a value that can quickly change the actual rotation angle MA is calculated as the duty signal Ds. Then, the operation control of the brushless motor 30 is executed based on the duty signal Ds.

  On the other hand, when the average value Piave is equal to or greater than the predetermined value H (step S23: NO), if the duty signal Ds is calculated in the first calculation mode at this time, the temperature of the brushless motor 30 may become excessively high. And the second calculation mode is selected as the calculation mode of the duty signal Ds (step S25). In this case, a value capable of suppressing an excessive temperature rise of the brushless motor 30 is calculated as the duty signal Ds based on the deviation between the target rotation angle TMA and the actual rotation angle MA. Specifically, this is a case where the deviation between the target rotation angle TMA and the actual rotation angle MA is increased by suppressing the increase speed of the duty signal Ds as compared with the case where the first calculation mode is selected. However, the amount of current supplied to the brushless motor 30 can be reduced by preventing the duty signal Ds from increasing.

Hereinafter, an effect of executing such a change process will be described.
In the control device according to the present embodiment, a larger amount of current is supplied to the brushless motor 30 as the change speed of the actual rotation angle MA is larger and as the change amount of the actual rotation angle MA is larger. The temperature of the brushless motor 30 is likely to increase excessively. In such a situation where the actual rotation angle MA of the brushless motor 30 changes, the deviation between the target rotation angle TMA and the actual rotation angle MA increases and the duty signal Ds changes greatly. The duty signal Ds changes from a value near the minimum value in the settable range to a value near the maximum value.

  In the present embodiment, two relational expressions determined by a linear function having the duty signal Ds as a variable are stored as arithmetic expressions used for calculating the estimated value Pi for the amount of current supplied to the brushless motor 30. In addition, as these relational expressions, relational expressions are set in which the deviation directions of the estimated value Pi based on the actual supply current amount (actual value Pr) are opposite to each other.

  FIG. 6 shows an example of the transition of the supply current to the brushless motor 30 when both the change speed and the change amount of the actual rotation angle MA are large. In the figure, the solid line indicates the estimated value Pi for the supply current, and the alternate long and short dash line indicates the actual value Pr for the supply current.

  In the present embodiment, as shown in FIG. 6, relational expressions different from the relational expressions capable of obtaining the actual value Pr based on the duty signal Ds are stored as the first relational expression and the second relational expression. Therefore, at that time, an error occurs between the estimated value Pi calculated from the first relational expression and the second relational expression and the actual value Pr.

  However, when the estimated value Pi is calculated and the average value Piave is obtained in the process in which the duty signal Ds changes greatly as described above, a part of the error (Pi−Pr) due to the calculation through the first relational expression. And a part of the same error calculated through the second relational expression are canceled out.

  Moreover, in the present embodiment, as the first relational expression and the second relational expression, the average of the values obtained by subtracting the estimated value Pi stored in the relational expression from the actual value Pr corresponding to the estimated value Pi is “ A relational expression of “0” is set. Therefore, when calculating the average value Piave, most of the errors calculated through the first relational expression and the second relational expression are offset by errors in different shift directions, and the calculation of the estimated value Pi The influence of errors can be minimized.

  Therefore, according to the present embodiment, when the operation control of the brushless motor 30 in a state where the duty signal Ds changes greatly is repeatedly performed and there is a concern about an excessive temperature rise of the brushless motor 30, the estimated value Pi As an average value Pave of, a value close to the average value of the actual value Pr is obtained. As a result, the temperature of the brushless motor 30 can be properly grasped from the average value Piave, and the operation control of the brushless motor 30 can be appropriately executed according to the grasped temperature. Become.

  Moreover, in the present embodiment, since the estimated value Pi is calculated through a calculation based on a relational expression determined by a linear function, the electronic control unit 32 is compared with a configuration in which the estimated value is calculated through a calculation based on a calculation map. It is possible to reduce the capacity of data stored in the memory. Furthermore, since the estimated value Pi can be calculated without using an interpolation method, the calculation load for the calculation can be reduced.

Therefore, according to the present embodiment, an excessive increase in the temperature of the brushless motor 30 can be suppressed with a simple control structure.
As described above, according to the present embodiment, the effects described below can be obtained.

  (1) Two relational expressions determined by a linear function having the duty signal Ds as a variable are set as arithmetic expressions used for calculating the estimated value Pi for the amount of current supplied to the brushless motor 30. In addition, as these relational expressions, relational expressions in which the deviation directions of the estimated value Pi based on the actual supply current amount (actual value Pr) are opposite to each other are set. Therefore, when the operation control of the brushless motor 30 in a state in which the duty signal Ds greatly changes is repeatedly executed and there is a concern about an excessive temperature rise of the brushless motor 30, an actual value is used as the average value Piave of the estimated value Pi. A value close to the average value of Pr can be obtained. As a result, the temperature of the brushless motor 30 can be properly grasped from the average value Piave, and the operation control of the brushless motor 30 can be appropriately executed according to the grasped temperature. Become. In addition, the capacity of the data stored in the memory of the electronic control unit 32 can be reduced, and further, the calculation load for calculating the estimated value Pi can be reduced. Therefore, an excessive increase in the temperature of the brushless motor 30 can be suppressed with a simple control structure.

  (2) As the first relational expression and the second relational expression, the average of the values obtained by subtracting the estimated value Pi stored in these relational expressions from the actual value Pr corresponding to the estimated value Pi is “0”. The relational expression was set. Therefore, when calculating the average value Piave, most of the errors caused by the calculation through the first relational expression and the second relational expression can be canceled by errors having different shift directions, and the error due to the calculation of the estimated value Pi. Can be minimized.

  (3) The operation control of the brushless motor 30 can be executed based on the transition of the supply current amount having a high correlation with the temperature of the brushless motor 30, and an excessive increase in the temperature of the brushless motor 30 can be accurately suppressed. .

  (4) The temperature of the brushless motor 30 can be properly grasped based on the average value Piave of the estimated values Pi in the latest predetermined period, and the operation control of the brushless motor 30 can be appropriately executed based on the temperature. it can.

The embodiment described above may be modified as follows.
Instead of obtaining the average value Piave of the estimated values Pi in the latest predetermined period, an integrated value of the estimated values Pi may be obtained. Even with such a configuration, it is possible to appropriately grasp the temperature of the brushless motor 30 based on the integrated value of the estimated value Pi.

  As the first relational expression and the second relational expression, a relational expression in which the average value obtained by subtracting the estimated value stored in the relational expression from the actual value Pr corresponding to the estimated value is not “0” is set. May be. In the same configuration, in order to suppress the influence of the error due to the calculation of the estimated value, the average of the values obtained by subtracting the estimated value from the actual value Pr corresponding to the estimated value becomes a value close to “0”. It is desirable to set a relational expression.

  Three or more relational expressions may be set as arithmetic expressions used for calculating an estimated value for the amount of current supplied to the brushless motor 30. Even in such a configuration, each relational expression is set so that the average of the values obtained by subtracting the estimated values stored in the relational expressions from the actual value Pr corresponding to the estimated values becomes “0”. Thus, when calculating the average value of the estimated values, most of the error (specifically, the difference between the estimated value and the actual value Pr) due to the calculation through each relational expression is canceled by the error in the deviation direction. Can do.

  Instead of calculating the estimated value for the amount of current supplied to the brushless motor 30, an estimated value for the temperature change amount of the brushless motor 30 may be calculated. In such a configuration, the temperature of the brushless motor 30 can be properly grasped based on the integrated value of the estimated values calculated as described above. Moreover, if it is an estimated value about the index value of the change amount per unit period of the temperature of the brushless motor 30, it is also possible to calculate an estimated value for the index value other than the supply current amount and the temperature change amount.

  -Variable motion for changing the opening / closing timing (so-called valve timing) of the intake valve 17 as well as the internal combustion engine provided with the variable valve mechanism 21 for changing the maximum lift amount and valve working angle of the intake valve 17 The control device according to the above embodiment can be applied to an internal combustion engine provided with a valve mechanism after the configuration thereof is appropriately changed. Further, the control device according to the above embodiment is provided for an internal combustion engine provided with a variable valve mechanism for changing the maximum lift amount and the valve operating angle of the exhaust valve 18 or for changing the valve timing of the exhaust valve 18. The present invention can also be applied to an internal combustion engine provided with a variable valve mechanism.

  The present invention can be applied not only to a control device that controls the rotation angle of an electric rotating machine but also to a control device that controls the operating position of an electric linear motor. The present invention is not limited to a control device that controls the operating position of an electric motor used as an operating source of a variable valve mechanism that changes the valve characteristics of an engine valve (intake valve or exhaust valve). The present invention can also be applied to a control device that controls the operating position of an electric motor used as an operating source of a throttle mechanism that changes the opening. In short, the present invention is applicable to any control device that controls the operation position of the electric motor through the operation control of the electric motor based on the operation command value.

1 is a cross-sectional view showing a cross-sectional structure around a cylinder head of an internal combustion engine to which an electric motor control device according to an embodiment embodying the present invention is applied. 1 is a schematic diagram showing a schematic configuration of a control device according to the embodiment. The flowchart which shows the execution procedure of an operation control process. The flowchart which shows the execution procedure of a change process. The graph which shows the relationship between the electric current amount supplied to a brushless motor, and a duty signal. The timing chart which shows an example of transition of the electric current amount supplied to a brushless motor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Cylinder head, 12 ... Cylinder block, 13 ... Piston, 14 ... Combustion chamber, 15 ... Intake passage, 16 ... Exhaust passage, 17 ... Intake valve, 18 ... Exhaust valve, 19 ... Intake camshaft, 19a ... intake cam, 20 ... exhaust camshaft, 20a ... exhaust cam, 21 ... variable valve mechanism, 22 ... rocker shaft, 23 ... control shaft, 24 ... input arm, 25 ... output arm, 26 ... spring, 27 ... rocker arm , 28 ... Rush adjuster, 29 ... Valve spring, 30 ... Brushless motor, 31 ... Conversion mechanism, 32 ... Electronic control unit, 33 ... Position sensor, 34 ... Accelerator position sensor, 35 ... Rotational speed sensor.

Claims (6)

A control means for controlling the operation position of the electric motor through the operation control of the electric motor based on the operation command value, and the relationship between the estimated value for the index value of the change amount per unit period of the temperature of the electric motor and the operation command value. Storage means for storing, and a change means for calculating the estimated value from the relationship based on the operation command value and changing an execution mode of the operation control of the electric motor based on the transition of the calculated estimated value. In an electric motor control device comprising:
The relationship consists of a plurality of relational expressions determined by a linear function with the operation command value as a variable,
These relational expressions consist of relational expressions set separately for each range obtained by dividing the settable range of the operation command value into a plurality of ranges, and the estimated values based on the actual values for the index values. A control apparatus for an electric motor, comprising: a first relational expression and a second relational expression in which shift directions are opposite to each other. In the control apparatus of the electric motor according to claim 1,
The relationship consists of two relational expressions determined by a linear function with the operation command value as a variable,
The two relational expressions include the first relational expression and the second relational expression. A control device for an electric motor, wherein: In the control apparatus of the electric motor according to claim 1 or 2,
The plurality of relational expressions are relational expressions in which an average of values obtained by subtracting estimated values stored in the relational expressions from the actual values is “0”. In the control apparatus of the electric motor as described in any one of Claims 1-3,
The index value is the amount of current supplied to the electric motor. In the control apparatus of the electric motor according to claim 4,
The change means changes the execution mode of the operation control of the electric motor based on an average value in a most recent predetermined period of the estimated value for the supply current amount. In the control apparatus of the electric motor according to any one of claims 1 to 5,
The control device is applied to an internal combustion engine provided with a variable valve mechanism for changing a valve characteristic of an engine valve.
The electric motor is an electric rotating machine used as an operation source of the variable valve mechanism,
The control device for the electric motor, wherein the control means calculates the operation command value according to an operating state of the internal combustion engine.

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