JP2015103544A - Storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a characteristic data use area in a storage device.SOLUTION: A storage unit 58 includes a code flash 60 and a data flash 62. Reference characteristic data of a control circuit 36 is stored in the code flash 60, and deviation data indicating the deviation between individual characteristic data and the reference characteristic data is stored in the data flash 62. The individual characteristic data is acquired on the basis of the reference characteristic data and the deviation data. A duty ratio is determined and supply current to a coil 30 is controlled on the basis of the individual characteristic data. Thus, the use area of the storage unit 58 can be reduced because the deviation data is stored, not the individual characteristic data. Also, accessibility can be improved because a free area of the data flash 62 can be enlarged.

Description

  The present invention relates to a storage device that stores characteristic data representing characteristics of a control circuit.

The EEPROM as a storage device described in Patent Document 1 stores element characteristic data representing characteristics of each circuit element of a control circuit including a solenoid coil and a plurality of circuit elements such as transistors and resistors. ing. The supply current to the coil is controlled based on the element characteristic data stored in the EEPROM.
The RAM as a storage device described in Patent Document 2 stores individual characteristic data representing actual characteristics of a control circuit including a solenoid coil. The supply current to the coil is controlled based on the individual characteristic data stored in the RAM.

JP 11-327602 A JP 2006-252416 A

  An object of the present invention is to improve the storage device, for example, by reducing the use area of the characteristic data representing the characteristics of the control circuit or by storing more accurate characteristic data. is there.

Means and effects for solving the problem

The storage device according to the present invention stores a first storage unit that stores reference characteristic data representing the reference characteristic of the control circuit, and deviation data that is a deviation between the individual characteristic data representing the individual characteristic of the control circuit and the reference characteristic data. And a second storage unit. Deviation data representing a difference (deviation) between the individual characteristic data and the reference characteristic data is acquired, and the deviation data is stored in a second storage unit different from the first storage unit in which the reference characteristic data is stored.
For example, the first storage unit may have a large storage capacity, but the stored information is rarely rewritten. Specifically, ROM, code flash, etc. are applicable. The first storage unit is often used mainly for storing a program code or the like in a design stage of a control circuit (including circuit elements such as switching elements).
For example, the second storage unit can have a smaller storage capacity than the first storage unit, and data can be rewritten (written or erased) more easily than the first storage unit. Specifically, an EEPROM, a data flash, etc. are applicable. The second storage unit is often used mainly for processing data acquired after design (learned values in a factory, learned values when used by a user, etc.).
The reference characteristic data can be uniform data representing, for example, a reference characteristic that is a characteristic of a control circuit determined at the design stage. The individual characteristic data can be data representing individual characteristics which are individual characteristics of the control circuit, for example. Individual characteristic data is actually acquired. The characteristic data is data representing the characteristics of the control circuit, and includes reference characteristic data, individual characteristic data, reference characteristic data, deviation data, deviation data, and the like. Since the deviation data is data representing a difference between the individual characteristics and the reference characteristics, it can be considered that the deviation data corresponds to the characteristics data.

As described above, in the present storage device, the reference characteristic data and the deviation data are stored in different storage units. Therefore, as compared with the case where the reference characteristic data and the deviation data are stored in the same storage unit. The area used for storing the characteristic data of the storage unit (the first storage unit or the second storage unit) (hereinafter simply referred to as the use region) can be reduced.
Further, when the individual characteristic data and the deviation data are compared, the deviation data can be represented by a smaller number of digits. Therefore, compared to the case where the reference characteristic data and the individual characteristic data are stored, the use area of the entire storage device can be reduced.
Furthermore, since the deviation data is stored in the second storage unit, the use area can be reduced as compared with the case where the individual characteristic data is stored. In other words, when the use area of the second storage unit is the same, the significant number of the deviation data can be increased correspondingly, and more accurate (high accuracy) individual characteristic data can be acquired. It becomes possible.
Further, if the reference characteristic data and the deviation data are stored, both the reference characteristic data and the individual characteristic data can be acquired, and the same data as when both the reference characteristic data and the individual characteristic data are stored. Can be acquired, and the amount of stored information can be reduced.

  On the other hand, the storage device according to the present invention can be provided in the solenoid control device. Individual characteristic data is acquired based on the reference characteristic data stored in the first storage unit and the deviation data stored in the second storage unit, and the current supplied to the coil of the solenoid based on the acquired individual characteristic data Is controlled. If the reference characteristic data and the individual characteristic data are stored in the second storage unit, or if the reference characteristic data is not stored and only the individual characteristic data is stored in the second storage unit, the second storage is performed. When the information stored in the unit disappears, it becomes difficult to control the current supplied to the coil satisfactorily. On the other hand, if the reference characteristic data is stored in the first storage unit and the deviation data is stored in the second storage unit, even if the data stored in the second storage unit disappears, the first storage unit Based on the reference characteristic data stored in the unit, it is possible to satisfactorily control the current supplied to the coil.

  The deviation data is acquired using factory equipment (external device) before the storage device is shipped, or after the storage device is shipped (when used by the user), for example, a solenoid control device or the like. Or can be done in In addition, the deviation data stored in the second storage unit in the factory can be changed as appropriate when the user uses it.

It is sectional drawing of the solenoid valve which has the solenoid of the object controlled by the solenoid control apparatus containing the memory | storage device which concerns on the Example of this invention. (a) It is a circuit diagram of the control circuit containing the said coil. (b) It is a figure which shows the change of the electric current in (a). It is a figure which shows the said solenoid control apparatus notionally. (a) It is a figure which shows notionally the external device which acquires the individual characteristic data of the said control circuit, and deviation data. (b) It is a flowchart showing programs, such as deviation data acquisition memorize | stored in the said external device. It is a figure which shows notionally the characteristic which is the relationship between the electric current and voltage in the said control circuit. It is a figure which shows the change of (a) electric current when a solid characteristic is acquired in the said external device. (b) It is a figure which shows notionally the acquired individual characteristic. It is a block diagram which shows notionally the control in the said solenoid control apparatus. It is a figure for demonstrating the interpolation method.

Embodiment of the Invention

Hereinafter, a storage device according to an embodiment of the present invention will be described. This storage device is provided in a solenoid control device mounted on the vehicle. The solenoid control device controls a supply current to a solenoid included in the solenoid valve. The electromagnetic valve controls the fluid pressure of an in-vehicle device (which can be referred to as a fluid pressure operating device or a fluid pressure control target device), for example, controls the fluid pressure of a fluid pressure brake that suppresses the rotation of a wheel. To control the fluid pressure (fluid inflow / outflow) in the vehicle height adjustment actuator that adjusts the distance between the vehicle body side member and the wheel side member, or to control the clutch hydraulic pressure of the transmission You can do it.
The fluid may be a liquid or a gas. Further, the solenoid that is the control target of the solenoid control device can be included in an actuator other than the electromagnetic valve.
Further, even if the deviation data is acquired by using an external device installed outside the vehicle, for example, in a factory, the deviation data is acquired by, for example, a solenoid control device mounted on the vehicle. May be.

[Solenoid control device]
Hereinafter, a solenoid control device including a storage device according to an embodiment of the present invention will be described in detail with reference to the drawings.
An example of a solenoid valve including a solenoid that is a control target of the solenoid control device is shown in FIG. The electromagnetic valve 10 includes a poppet valve portion 12 and a solenoid 14. The poppet valve unit 12 includes a valve element 20, a valve seat 21, a spring 22, and the like. The solenoid 14 includes a coil 30 and a plunger 32. The plunger 32 is operated by controlling the supply current to the coil 30, and the valve element 20 is moved toward and away from the valve seat 21 accordingly. The electromagnetic valve 10 is provided in a posture in which a force corresponding to a differential pressure between the high pressure side and the low pressure side acts in a direction to separate the valve element 20 from the valve seat 21. In the solenoid valve 10 shown in FIG. 1, a high pressure source is connected to the high pressure side, a fluid pressure actuator is connected to the low pressure side, and the fluid pressure of the fluid pressure actuator is controlled.

A control circuit 36 including the coil 30 is shown in FIG. The control circuit 36 includes a coil 30, a power supply 40, a switching element 42, and the like connected in series. The resistor 44 is an equivalent description of the overall resistance of the control circuit 36 such as the resistance of an IC having the coil 30 and the switching element 42. A current monitor 46 is connected to the control circuit 36.
The switching element 42 can be a transistor, for example, and by controlling the duty, the voltage applied to the coil 30 is controlled, and the current flowing through the coil 30 is controlled. Since the voltage applied to the coil 30 is larger when the duty ratio is large than when it is small, in this embodiment, the voltage is represented by the duty ratio.
In the control circuit 36 shown in FIG.
u (t) = R · i (t) + L · di (t) / dt
Is established. u (t) is a voltage applied to the coil 30 by duty control of the switching element 42, and i (t) is a current flowing through the coil 30. L is the inductance of the coil 30, and R is the resistance value of the entire control circuit 36.
When the above equation is Laplace transformed (d / dt = s), the following equation is obtained.
I (s) = {1 / (L · s + R)} · U (s)
As shown in the above equation, the transfer function between the voltage (duty ratio) and the current is expressed by a first-order lag response equation. As shown in FIG. 2B, the current value increases with a delay with respect to the change in the duty ratio (transiently), and thereafter (steadily) with a constant magnitude determined by the duty ratio and the resistance value. Become.

The drive circuit 48 including the switching element 42 and the like is controlled by the controller 50, and the supply current to the coil 30 is controlled. In the present embodiment, as shown in FIG. 3, the drive circuit 48, the controller 50, and the like constitute an ECU 52 as a solenoid control device. The controller 50 is mainly a computer, and includes an input / output unit 54, an execution unit 56, a storage unit 58, and the like. The input / output unit 54 is connected to a plurality of sensors (not shown) and a drive circuit 48 and the like. Although a plurality of drive circuits are often connected to the input / output unit 54, one of them is shown in FIG. In the execution unit 56, a control command value is created based on the sensor detection value and the like input via the input / output unit 54 and the program and data stored in the storage unit 58. The storage unit 58 includes a code flash 60 and a data flash 62, and stores a plurality of programs, data, and the like.
The code flash 60 has a larger storage capacity than the data flash 62, and mainly stores program codes, data, and the like created in the design stage of the ECU 52, the solenoid valve 10 (solenoid 14), and the like. In the present embodiment, reference characteristic data representing a reference characteristic as one of the characteristics of the control circuit 36 is stored.
The data flash 62 has a smaller storage capacity than the code flash 60 and can be easily rewritten (written or erased). Mainly, a factory, a learning value acquired at the time of use by a user after design, and the like are stored, and deviation data representing a deviation between individual characteristic data representing one characteristic of the control circuit 36 and reference characteristic data Is memorized.
As apparent from FIG. 3, the storage unit 58 is a component of the ECU 52, and both the code flash 60 and the data flash 62 are provided in the ECU 52.

In the present embodiment, the characteristics of the control circuit 36 are the same as the voltage applied to the coil 30 (represented by the duty ratio in the present embodiment) and the current flowing through the coil 30 (current flowing through the control circuit 36). Can be considered). The reference characteristic (reference model) is a characteristic determined at the design stage and is a uniform characteristic. An example of reference characteristic data representing the reference characteristic is shown by a solid line in FIG. 5 (current x, duty ratio y as voltage).
y = a · x + b
The reference characteristic data is stored in the code flash 60 at the design stage.
Based on the reference characteristics, the drive circuit 48, the solenoid 14 and the like are designed and manufactured. Due to individual variations of the drive circuit 48 (IC circuit including the switching element 42), the coil 30, etc. Thus, individual characteristics of the control circuit 36 may deviate from the reference characteristics. Therefore, in this embodiment, individual characteristics (individual models), which are individual actual characteristics of the control circuit 36, are acquired using the equipment of the vehicle assembly factory before the vehicle is shipped. Then, deviation data is obtained by subtracting the reference characteristic data from the individual characteristic data representing the individual characteristic, and is stored in the data flash 62.

[Obtain deviation data]
As described above, the deviation data is acquired using equipment (referred to as the external device 70) of the vehicle assembly factory. As shown in FIG. 4A, the external device 70 is mainly a computer and is connected to the ECU 52. The individual characteristic data and deviation data of the control circuit 36 are acquired by data communication between the external device 70 and the ECU 52, and the data is represented by the flowchart of FIG. 4B stored in the external device 70. Is performed according to the execution of the program to be executed. 4A shows a case where the external device 70 and the ECU 52 are connected, the external device 70 and the control circuit 36 are connected by the function of the external device 70, or the external device 70 and the controller are connected. 50 may be connected. Moreover, about a power supply, an electric current monitor, etc., the installation in a factory can also be used.

In step 1 (hereinafter abbreviated as S1, the same applies to other steps), individual characteristic data for the control circuit 36 is acquired. The individual characteristic data can be represented by, for example, one straight line acquired based on a plurality of actual measurement points (x _k , h _k ).
The actual measurement points (x _k , h _k ) are x−h expressed by the current actually flowing through the control circuit 36 detected by the current monitor 46 and the duty ratio used for the actual control of the switching element 42. A point on the coordinates. The actual measurement points can be acquired as representative values (for example, average values) detected and statistically processed multiple times.
For example, information representing the set current values (x ₁ , x ₂ , x ₃ ,...) Shown in FIG. 6A is sequentially supplied from the external device 70 to the ECU 52. In the ECU 52, the duty ratio (h ₁ , h ₂ , h ₃ ...) At which the current detected by the current monitor 46 becomes the set current value is obtained by changing the duty ratio. Then, information representing the acquired duty ratios (h ₁ , h ₂ , h ₃ ...) Is supplied from the ECU 52 to the external device 70. In the external device 70, as shown in FIG. 6B, a plurality of different measurement points (x _k , h _k ) are acquired.
A straight line representing individual characteristic data is acquired (for example, by the method of least squares) based on the acquired plurality of actual measurement points (x _k , h _k ), and an example thereof is indicated by a one-dot chain line in FIG.
h = γ · x + c
Incidentally, the duty ratio when the current zero _{(x 0) (h 0)} can be obtained as the intercept of the dashed line _(h 0 = c).

Deviation data is acquired in S2. The deviation is the difference between the duty ratio of the individual characteristic data and the duty ratio of the reference characteristic data for the same current. For example, as shown in FIG. 5, the deviation data Δy _{k is} obtained by subtracting the duty ratio (y _k ) of the reference characteristic data from the duty ratio (h _k ) of the individual characteristic data corresponding to each of the set current values (x _k ). Is acquired.
Δy _k = h _k −y _k
(Δy ₀ , Δy ₁ , Δy ₂ , Δy ₃ ...)
For example, the reference characteristic data read from the code flash 60 in the ECU 52 is supplied to the external device 70, and the deviation data Δy _k is acquired in the external device 70 using the individual characteristic data acquired in S1. can do.
In S 3, the obtained deviation data Δy _k is stored in the data flash 62. For example, the external device 70 supplies the ECU 52 with the deviation data Δy _k and outputs a command or the like for storing the deviation data Δy _k in the data flash 62 of the storage unit 58. In the ECU 52, the deviation data Δy _k is stored in the data flash 62.
Note that the duty ratio at the actual measurement point may be used as the duty ratio h _k of the individual characteristic data used when obtaining the deviation data. This is because it can be considered that individual characteristic data is represented by a plurality of actually measured points.

Thus, in this embodiment, deviation data representing the deviation between the reference characteristic data and the individual characteristic data is acquired and stored, and the storage unit 58 as a storage device is manufactured. The data flash 62 has a smaller storage capacity than the code flash 60, and is easy to write and erase data, so it is used for processing a large amount of data. Therefore, it is desirable to increase the usable area (empty area) of the data flash 62.
On the other hand, when the individual characteristic data and the deviation data are compared, the deviation data uses a smaller amount of data. For example, the capacity used when individual characteristic data composed of _n duty ratios h (h ₀ , h ₁ , h ₂ ,... H _n−1 ) is stored in the data flash 62 is Q (byte) × n (pieces) × α. α is a value determined according to a plurality of storage methods (for example, for fail-safe). On the other hand, when the deviation data composed of _n deviations (Δy ₀ , Δy ₁ , Δy ₂ ,... Δy _n−1 ) is stored, the capacity used is Q ′ (byte) × n (pieces) × α. The capacity used by one piece of data is smaller in the deviation (duty ratio difference) than the absolute value of the duty ratio (Q '<Q). The use area of 62 can be reduced. As a result, the free area of the data flash 62 can be increased, and the accessibility of the data flash 62 can be improved.
Further, if the use area is the same, the significant number of the deviation data can be increased correspondingly, and the individual characteristic data can be obtained with high accuracy.
Since the set current value (x _k ) is determined in advance, it is not necessary to store the duty ratio representing the characteristic in association with the current value, and the use area can be reduced accordingly.
As described above, after the reference characteristic data is stored in the code flash 60 and the deviation data is stored in the data flash 62 and the storage unit 58 is manufactured, the vehicle is shipped.

Note that at least one of the first storage unit and the second storage unit may be provided outside the ECU (for example, the first storage unit may be a ROM and the second storage unit may be an EEPROM). it can.). In that case, a solenoid control device is constituted by the ECU and the external memory.
In this embodiment, the individual characteristic data is acquired and stored in the data flash 62 in a vehicle assembly factory or the like, but the individual characteristic is being controlled during actual solenoid control after the vehicle is shipped. Data may be acquired and stored in the data flash 62, or the data stored in the data flash 62 may be appropriately changed according to the individual characteristic data acquired during solenoid control.
Furthermore, the present invention is not limited to the deviation data that is the deviation between the individual characteristic data and the reference characteristic data, and deviation-related data corresponding to the deviation on a one-to-one basis may be stored. The individual characteristic data is acquired based on the deviation related data and the reference characteristic data, and the supply current to the coil 30 is controlled based on the individual characteristic data.

[Control of current supplied to solenoid]
Next, an example of control of the supply current to the coil 30 in the ECU 52 provided with the storage unit 58 will be described with reference to FIG.
In the target current calculation unit 80, a target current xref that is a target value of a supply current to the coil 30 is determined based on detection values of a plurality of sensors. For example, the target current xref can be determined so that the target fluid pressure of the fluid pressure actuator is achieved. In the target duty ratio determination unit 82, the individual characteristic data of the control circuit 36 is acquired based on the reference characteristic data stored in the code flash 60 and the deviation data stored in the data flash 62, and the acquired individual characteristic data And the target current xref, the target duty ratio Dref when controlling the switching element 42 is determined using an interpolation method.
Specifically, when the target current xref is input, as shown in FIG. 8, two set current values x _k and x _{k + 1} with the target current xref positioned therebetween are acquired (x _k <xref <x _{k + 1} ). Reference characteristic data (y _k , y _{k + 1} ) and deviation (Δy _k , Δy _{k + 1} ) corresponding to them are acquired, and individual characteristic data (h _k , h _{k + 1} ) are acquired.
h _k = y _k + Δy _k
h _{k + 1} = y _{k + 1} + Δy _{k + 1}
Then, the slope β of the straight line representing the individual characteristics between the two set current values x _k and x _{k + 1} is acquired, and the target duty ratio Dref that can obtain the target current xref is determined.
β = (h _{k + 1} −h _k ) / (x _{k + 1} −x _k )
Dref = β · xref + c
c = y ₀ + Δy ₀ = b + Δy ₀

  In the temperature corresponding correction unit 84, the duty ratio Dref determined by the target duty ratio determination unit 82 is corrected using the temperature correction coefficient KT and output (duty ratio Dout). Since the resistance value R of the control circuit 36 changes as the temperature changes, the characteristics of the control circuit 36 also change. Therefore, the temperature correction coefficient KT is acquired and corrected based on the resistance value or the like when the temperature of the coil 30 is an actual temperature or a temperature close thereto. Further, the duty ratio Dout output by the temperature correspondence correction unit 84 is a feedforward control command value DFF. Further, the correction can be made not only in the temperature but also in the environment where the characteristics are affected. In this case, the correction can be called an environment compatible correction unit.

  In the power supply voltage correction unit 86, the input duty ratio Dout is corrected and output based on the voltage level of the power supply 40 (Dout1). When the power supply voltage is low, the input duty ratio Dout is corrected to be larger than when the power supply voltage is high. The relationship between the power supply voltage and the correction value of the duty ratio is acquired in advance, and is mapped and stored, for example. In the noise removing unit 88, when the input duty ratio Dout1 is not between a lower limit value (for example, 0) and an upper limit value (for example, 100%), the lower limit The value or the upper limit value is determined and output (Dout2). The duty output unit 90 supplies the current corresponding to the coil 30 by driving the switching element 42 with the duty ratio Dout2.

On the other hand, an actual current that is an actual current flowing through the coil 30 is detected by the current monitor 46 and fed back.
In the A / D converter 92, the actual current xa (analog value) detected by the current monitor 46 is converted into a digital value and output. The current monitor correction unit 94 corrects the input digital value based on the temperature of the current monitor 46 and the like. In the digital filter 96, noise and the like are removed and smoothed. In this embodiment, the moving average value is acquired and output (xaf).
The actual duty ratio acquisition unit 98 acquires the duty ratio Daf corresponding to the actual current xaf based on the input actual current xaf and the individual characteristic data.
Specifically, two set current values x _m and x _{m + 1 in} which the actual current xaf is located in the middle are acquired (x _m <xaf <x _{m + 1} ), and the corresponding reference characteristic data (y _m , y _{m + 1} ) , Deviation (Δy _m , Δy _{m + 1} ) is acquired, and individual characteristic data (h _m , h _{m + 1} ) is acquired. Then, the slope β ′ between the two set current values x _m and x _{m + 1} is acquired, and the actual duty ratio Daf corresponding to the actual current xaf is determined.
β ′ = (h _{m + 1} −h _m ) / (x _{m + 1} −x _m )
Daf = β ′ · xaf + c
Then, a deviation (Dref−Daf) that is a difference between the duty ratio Daf corresponding to the actual current xaf and the duty ratio Dref corresponding to the target current Iref is acquired and supplied to the PID control unit 00. In the PID control unit 100, the feedback control value DFB is acquired so that the deviation of the duty ratio (Dref−Daf) becomes small. Then, it is added to the feedforward command value DFF output from the temperature correspondence correction unit 304.

As described above, in this embodiment, individual characteristic data is acquired based on the reference characteristic data stored in the code flash 60 and the deviation data stored in the data flash 62, and the switching element is determined based on the individual characteristic data. The duty ratio to 42 is determined. Since the control of the supply current to the coil 30 is performed based on the actual individual characteristics of the control circuit 36, the supply current can be accurately controlled. As a result, the responsiveness of the fluid pressure actuator can be improved, and the fluid pressure control accuracy can be improved.
Further, since the reference characteristic data is stored in the code flash 60, the feedforward control value DFF is created based on the reference characteristic data even if the deviation data stored in the data flash 62 disappears due to some cause. It becomes possible.

  In this embodiment, the storage unit 58 corresponds to a storage device, the code flash 60 corresponds to a first storage unit, and the data flash 62 corresponds to a second storage unit. The external device 70 can also be called a deviation data acquisition device, a deviation data acquisition / storage control device, or a storage device creation device.

  The present invention can be implemented in variously modified and improved modes based on the knowledge of those skilled in the art, in addition to the modes described in the above embodiments.

  10: Solenoid valve 14: Solenoid 30: Coil 42: Switching element 46: Current monitor 48: Drive circuit 50: Controller 52: ECU 58: Storage unit 60: Code flash 62: Data flash 70: External device 82: Target duty ratio determination Unit 98: Actual duty ratio determining unit

Claims (1)

A storage device for storing characteristic data representing a characteristic that is a relationship between voltage and current in a control circuit including a coil,
A first storage unit that stores reference characteristic data representing a reference characteristic that is the relationship determined in advance for the control circuit;
A storage device, comprising: a second storage unit that stores deviation data that is a deviation between individual characteristic data representing individual characteristics that are the individual actual relationships of the control circuit and the reference characteristic data.

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