JP2010245282A - Solenoid control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid control device capable of controlling a current which is supplied to a solenoid with high reliability, when drive-controlling a solenoid, even if there exist a plurality of solenoids. <P>SOLUTION: A feedback control system feedback-corrects a duty ratio by a microcomputer so that a target current is kept while monitoring a supply current to solenoids 101-104 that are duty-controlled. The fluctuations in the supply current to the solenoids 101-104, which is caused by the fluctuations in battery voltage to be monitored is deduced, while monitoring the battery voltage through an interruption process part 229 provided to the feedback path, and the correction for the duty ratio is performed, in a manner of the deduced fluctuations of the supply current being suppressed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solenoid control device that controls driving while adjusting a current supplied to a solenoid such as a solenoid valve.

  Conventionally, as this type of solenoid control device, for example, there is one that is adopted in the brake control device described in Patent Document 1. FIG. 5 shows an outline of an example in which the brake control device described in Patent Document 1 is applied to a control unit (ECU) integrated actuator structure.

  That is, this brake control device is configured by integrally configuring a liquid actuator unit including various electromagnetic valves and a control unit (brake ECU) that controls driving of the liquid actuator unit. In such a brake control device in which the liquid actuator unit and the control unit are integrated, the details of the operation are subject to the description in the same document, and the influence of heat generation due to the high density of parts is particularly remarkable. is there. Therefore, in order to reduce the influence of such heat generation, after starting current is supplied to solenoids such as simulator cut valves, master cut valves, regulator cut valves, communication valves (separation valves), etc. Control such as switching to a holding current having a current value smaller than the current is performed. Then, after the current supplied to the solenoid of one of the solenoid valves is switched from the starting current to the holding current, the supply of the starting current to the solenoid of the next solenoid valve is started. Thus, by switching the current supplied to each electromagnetic valve to the starting current and the holding current smaller than that, the power consumption in the solenoid of each electromagnetic valve can be reduced.

  On the other hand, in order to accurately switch the current supplied to the solenoid, it is necessary to control the current with high accuracy according to the current supplied to the solenoid. For this reason, for example, a solenoid control device described in Patent Document 2 has been proposed as a device that enables highly accurate current control for such a solenoid.

  In the solenoid control device described in Patent Document 2, the current flowing through the solenoid is monitored, and the current value serving as a switching condition from constant voltage driving for supplying the starting current to the solenoid to pulse driving for supplying the holding current to the solenoid, and this value Current feedback control is performed to determine whether or not the switching is necessary by comparing with the monitored current.

JP 2007-230432 A JP 2008-16621 A

As described above, according to the solenoid control device described in Patent Document 2, the feedback control for switching between the constant voltage driving and the pulse driving is performed based on the monitoring result of the current flowing through the solenoid. It is possible to perform drive control of the solenoid valve according to the above. However, if such a solenoid control device is applied to the above-described control unit (ECU) integrated actuator structure, the following inconveniences cannot be ignored. That is, in the brake control device having the same structure, the solenoid current of the above-described simulator cut valve, master cut valve, regulator cut valve, communication valve (separation valve), etc. is basically collectively controlled by one microcomputer. Therefore, even if these solenoid currents are monitored, it is usually necessary to A / D (analog / digital) convert these currents in a time-sharing manner using a multiplexer or the like. For this reason, even when using interrupt processing of a microcomputer, there will be a period during which monitoring becomes impossible for each solenoid current, and there is room for improvement in order to further improve the accuracy and reliability of current feedback control. is there.

  In addition, not only the above-described control unit (ECU) integrated actuator structure, but also in a feedback control system that basically monitors solenoid currents such as a plurality of solenoid valves with a single microcomputer, such a situation is generally common. It has become.

  The present invention has been made in view of the above circumstances, and can control the current supplied to the solenoid with high reliability even when the number of the solenoids is controlled when driving the solenoid. An object is to provide a solenoid control device.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
According to the first aspect of the present invention, duty control is performed so that the supply current to the solenoid is duty-controlled based on the battery voltage, and the supply current to the solenoid is maintained at a target current each time. In the solenoid control device that corrects the ratio, while monitoring the battery voltage, the fluctuation in the supply current to the solenoid due to the fluctuation in the monitored battery voltage is estimated, and the fluctuation in the estimated supply current is suppressed. The gist is that the duty ratio is corrected in an aspect.

  The battery voltage as the power supply voltage of the solenoid is not necessarily constant and varies depending on the use environment and load. When such battery voltage fluctuation occurs, the current supplied to the solenoid also fluctuates due to this battery voltage.

  In this regard, if the battery voltage is directly monitored as in the above-described configuration, it is possible to estimate the fluctuation in the supply current to the solenoid caused by the battery voltage. Then, by correcting the duty ratio in such a manner that fluctuations in the estimated supply current are suppressed, the supply current to the solenoid can be maintained at the target current each time. In addition, since the battery voltage can be constantly monitored regardless of the number of solenoids, if the duty ratio for duty control is corrected based on the battery voltage in this way, this battery Even when there are a plurality of solenoids driven by voltage, the current supplied to the solenoids can be controlled with high reliability.

  According to a second aspect of the present invention, in the solenoid control device according to the first aspect, the duty ratio is set to a microcomputer so as to be maintained at a target current while monitoring a supply current to the duty-controlled solenoid. A feedback control system that performs feedback correction according to the following: monitoring of the battery voltage, estimation of fluctuation of the supply current to the solenoid based on the monitoring of the battery voltage, and correction of the duty ratio with respect to the fluctuation of the estimated supply current The gist of the present invention is that it is executed as interrupt processing by the microcomputer added to the feedback path of the feedback control system.

Normally, interrupt processing by a microcomputer can be executed at a high frequency (for example, 480 μsec) with respect to a calculation cycle (for example, 6 msec) of a main routine for feedback control, for example. Therefore, as in the above configuration, if each process of monitoring the battery voltage, estimating the fluctuation of the supply current, and correcting the duty ratio is executed as an interrupt process by the microcomputer, each process is performed. It is possible to execute with high accuracy. As a result, even when the supply currents to a plurality of solenoids are monitored in a time division manner, the supply currents can be reliably managed regardless of the number of solenoids.

  According to a third aspect of the present invention, in the solenoid control device according to the second aspect, the interrupt processing is performed on the solenoid estimated from a rate of decrease of the battery voltage within a predetermined time in which the interrupt processing is repeated. The gist is that the duty ratio is increased when the value of the supply current is less than the minimum holding current, which is the minimum current value that can hold the driving state of the solenoid at a minimum.

  According to the above configuration, the duty ratio increase correction is performed in a state in which the supply current supplied to the solenoid is less than the minimum holding current due to the decrease in the battery voltage. As a result, even when the battery voltage has a decreasing tendency, the solenoid driving state can be properly maintained.

According to a fourth aspect of the present invention, in the solenoid control device according to the third aspect, it is determined that the value of the supply current to the solenoid estimated from the rate of decrease of the battery voltage is less than the minimum holding current. , VBmax is the maximum value of the battery voltage sampled within the predetermined time during which the interrupt processing is repeated, SVBn is the sampling value after the maximum value of the battery voltage, and the monitor value of the supply current to the solenoid at each predetermined time is Is, where the minimum holding current is Imin,

(SVBn / VBmax) <(Imin / Is)

The gist of this is that the relationship is satisfied.

  According to the above configuration, the sampled constant time based on the maximum value (VBmax) of the battery voltage sampled within a certain time during which the interrupt process is repeated and the sampling value (SVBn) after the maximum value of the battery voltage. The battery voltage drop rate (SVBn / VBmax) can be obtained. Then, the rate of change (Imin / Is) determined by the calculated rate of decrease of battery voltage (SVBn / VBmax), the monitor value (Is) of the current supplied to the solenoid every fixed time, and the minimum holding current (Imin) On the basis of the comparison, it can be determined whether or not the current supplied to the solenoid fluctuates in a transition that does not satisfy the minimum holding current. As a result, it is possible to execute the control related to the duty ratio increase correction by the interrupt process, and hence the control for increasing the supply current to the solenoid, with high accuracy.

  According to a fifth aspect of the present invention, in the solenoid control device according to the second aspect, the interrupt processing is performed on the solenoid estimated from a rate of increase of the battery voltage within a predetermined time in which the interrupt processing is repeated. The gist of the present invention is that the duty ratio is reduced when the supply current value reaches the output IC maximum guaranteed current, which is the maximum current value that can guarantee the operation of the output IC that controls the driving of the solenoid.

  According to the above configuration, the duty ratio reduction correction is performed in a state where the supply current supplied to the solenoid due to the rise in the battery voltage reaches the output IC maximum guaranteed current. As a result, even when the battery voltage has a rising tendency, the solenoid drive state including the output IC state can be properly maintained.

According to a sixth aspect of the present invention, in the solenoid control device according to the fifth aspect, it is determined that the value of the supply current to the solenoid estimated from the rate of increase of the battery voltage reaches the maximum guaranteed current of the output IC. However, the minimum value of the battery voltage sampled within the predetermined time when the interruption process is repeated is VBmin, the sampling value after the minimum value of the battery voltage is SVBn, and the monitor value of the supply current to the solenoid at the predetermined time Is Is and the output IC maximum guaranteed current is Imax,

(SVBn / VBmin)> (Imax / Is)

The gist of this is that the relationship is satisfied.

  According to the above configuration, the sampled constant time based on the minimum value (VBmin) of the battery voltage sampled within a fixed time during which the interrupt process is repeated and the sampled value (SVBn) after the minimum value of the battery voltage. The battery voltage increase rate (SVBn / VBmin) can be obtained. The battery voltage increase rate (SVBn / VBmin), the monitor current value (Is) of the current supplied to the solenoid every fixed time, and the output IC maximum guaranteed current (Imax) are obtained as a fluctuation rate (Imax / Based on the comparison with Is), it is possible to determine whether or not the current supplied to the solenoid fluctuates in a transition that reaches the output IC maximum guaranteed current (Imax). As a result, the duty ratio reduction correction by the interrupt process, and hence the control for reducing the supply current to the solenoid can be executed with high accuracy.

  According to a seventh aspect of the present invention, in the solenoid control device according to any one of the second to sixth aspects, the duty ratio that is feedback-corrected in the feedback control system includes a supply current to the monitored solenoid. The gist is that the temperature change of the solenoid monitored based on the value of the above is compensated and added.

  Usually, the inductance and resistance of the coil constituting the solenoid change in correlation with the temperature of the solenoid. Specifically, the amount of current flowing therethrough decreases as the temperature of the solenoid increases. In this regard, as described above, if the temperature variation of the monitored solenoid is compensated and added to the feedback-corrected duty ratio based on the value of the current supplied to the monitored solenoid, the temperature of the solenoid The duty ratio can be corrected according to the characteristics. As a result, the current supplied to the solenoid can be controlled with higher reliability.

  According to an eighth aspect of the present invention, in the solenoid control device according to any one of the first to seventh aspects, the liquid in the brake control device in which the solenoid that is a target of the duty control is formed of a control unit integrated actuator structure. The gist is that the solenoid is provided in each of a plurality of solenoid valves for pressure control.

  As described above, according to the present invention, a plurality of solenoid valves for hydraulic pressure control in a brake control device including a controller-integrated actuator structure, specifically, a simulator cut valve, a master cut valve, and a regulator cut valve described above. It is particularly effective when applied to the solenoids provided in each of the communication valves (separation valves). Through the above-described solenoid drive control, the drive control of the solenoids provided in each of these solenoid valves is performed with high reliability. Be able to run.

The block diagram which shows the functional structure about one Embodiment which applied the solenoid control apparatus concerning this invention to the control of the solenoid provided in the solenoid valve of the control part (ECU) integrated actuator structure. (A) is a time chart which shows the transition example of the battery voltage applied to a solenoid. (B) is a time chart showing a transition example of the current supplied to the solenoid based on the battery voltage. The flowchart which shows the example of a process sequence about the interruption process at the time of the voltage fall performed in the solenoid control apparatus of the embodiment. The flowchart which shows the example of a process sequence about the interruption process at the time of the voltage rise performed in the solenoid control apparatus of the embodiment. The block diagram and hydraulic circuit diagram which show the structural example of the control system about the control part (ECU) integrated actuator structure which comprises a brake control apparatus.

  FIG. 1 shows the configuration of an embodiment embodying a solenoid control device according to the present invention.

  The solenoid control device of the present embodiment is also a brake control device made up of, for example, the control unit (ECU) integrated actuator structure shown in FIG. 5, and the simulator cut valve, master cut valve, regulator cut valve described above. 1 is configured as a device for controlling the driving of a solenoid provided in an electromagnetic valve such as a communication valve (separation valve), and is largely a control unit for controlling the driving of the actuator unit 100 shown in FIG. (ECU) 200 and a battery 300 that supplies power to them are configured. In this embodiment, the solenoids 101 to 104 that are solenoids of the electromagnetic valves constituting the brake control device are controlled.

Among these, the battery 300 is, for example, a battery mounted on a vehicle, and the voltage thereof usually varies depending on the electric load of the vehicle, the operating state of the engine, and the like.
On the other hand, as is well known, the solenoids 101 to 104 constituting the actuator unit 100 are actuators in which a movable iron core is installed in the coil, and the movable iron core is linearly moved by electromagnetic force generated by passing a current through the coil. . And although each said solenoid valve driven by such solenoids 101-104 requires a big current as a starting current at the time of starting, once starting, holding current which is a current smaller than this starting current is taken. The driving state can be maintained by supplying. For this reason, by switching the current supplied to the solenoids 101 to 104 from the starting current to the holding current in accordance with the driving state of each solenoid valve, the consumption as the control unit (ECU) integrated actuator structure as described above is achieved. Electric power and heat generation can be minimized. In the present embodiment, such control of the supply current to the solenoids 101 to 104 is performed through duty control using PWM (pulse width modulation) by a control unit (ECU) 200 described below.

  The control unit (ECU) 200 constituting the control unit (ECU) integrated actuator structure is equivalent to a solenoid relay 210 capable of interrupting power supply from the battery 300 to the solenoids 101 to 104, equivalently to FIG. A microcomputer 220 having the configuration illustrated in FIG. 5 and executing current feedback control and interrupt processing, and driving the solenoids 101 to 104 based on a duty ratio command generated through the microcomputer 220, And an output IC 230 that monitors the flowing current.

Of these, the microcomputer 220 first depresses the brake pedal (see FIG. 5), and when a user command corresponding to the amount of depression, the stepping speed, or the like is input, the solenoids are operated according to the user command. A target current to be supplied to 101 to 104 is set by the target current setting unit 221. Based on the set target current, the duty ratio when the solenoids 101 to 104 are PWM driven is a current-duty conversion map 22.
2 is calculated. The temperature change monitoring unit 223a monitors the temperature change of the solenoids 101 to 104 based on the monitor value of the current supplied to the solenoids 101 to 104, and the monitoring result is taken into the temperature compensation circuit (KT) 223b. It is. This temperature compensation circuit (KT) 223b compensates for the duty ratio calculated by the above map so that a larger current flows as the coil temperature becomes higher, based on the phenomenon that the current becomes harder to flow as the coil (solenoid) temperature becomes higher. This is a circuit that performs gain setting (compensation addition). The temperature compensated duty ratio is output from the microcomputer 220 as a drive command for the output IC 230.

  When a signal indicating the duty ratio is output as a drive command from the microcomputer 220 in this way, the output IC 230 generates a drive pulse corresponding to the duty through the PWM drive unit 231, and a transistor (P-channel FET) is generated by the generated drive pulse. ) 232 is turned on / off. As a result, the battery voltage supplied via the solenoid relay 210 is applied to the solenoids 101 to 104 as a duty signal pulsed in synchronization with the on / off timing of the transistor 232, and the duty signal The current corresponding to the duty ratio (average current) is supplied to the solenoids 101-104.

  On the other hand, in the control unit (ECU) 200, the current supplied to the solenoids 101 to 104 is taken in as a voltage value proportional to the internal resistance via the other transistor (N-channel FET) 233 of the output IC 230. It is. Then, the captured voltage is converted into a current value via the voltage / current conversion unit 234, and the converted current value is input to the microcomputer 220 as a monitor current of the current supplied to the solenoids 101 to 104. .

  As a result, the microcomputer 220 quantizes the input current by the A / D conversion unit 225 and obtains a moving average value for every predetermined time (fixed period) through the digital filter 226. Then, the calculated moving average value of the monitor current is compared with the value of the target current monitored by the target current monitoring unit 224 corresponding to the duty ratio calculated through the previous current-duty conversion map 222. Based on this comparison, the temperature-compensated duty value is feedback-corrected through the known PI controller 228 so that the monitor current coincides with the target current at an early stage. By configuring such a feedback control system with the microcomputer 220 and the output IC 230, the value of the current supplied to the solenoids 101 to 104 is controlled in such a way as to follow the target current set based on the user command. become. In the feedback control system, the starting current and the holding current are automatically switched through the target current setting unit 221.

  By the way, as described above, the voltage of the battery 300 serving as a driving power source for the solenoids 101 to 104 varies depending on the electric load of the vehicle, the operating state of the engine, and the like. And when such a fluctuation | variation arises in the voltage of the battery 300, the electric current supplied to the solenoids 101-104 will also fluctuate in the form which follows the fluctuation | variation. That is, for example, the battery voltage decreases due to such voltage fluctuation of the battery 300, and the current supplied to the solenoids 101 to 104 due to the decrease in the battery voltage is the minimum current value that can maintain the driving state at a minimum. When the minimum holding current Imin is not reached, the driving state of the solenoids 101 to 104 cannot be maintained. On the other hand, for example, the battery voltage rises due to the fluctuation of the battery voltage, and the current supplied to the solenoids 101 to 104 due to the rise of the battery voltage is the maximum current value that can guarantee the operation of the output IC 230. When the guaranteed current Imax is reached, proper operation as the output IC 230 cannot be guaranteed.

  Therefore, in the present embodiment, an interrupt processing unit 229 is provided in the feedback path of the feedback control system configured in the microcomputer 220 via a pseudo switch 227, and the battery voltage fluctuation is periodically detected through the interrupt processing unit 229. To monitor. Then, the current supplied to the solenoids 101 to 104 is estimated from the monitoring result, and further necessary correction is added to the duty ratio to be feedback-corrected based on the estimated current. Note that such monitoring of the battery voltage by the interrupt processing unit 229 is performed via the solenoid relay 210.

  FIG. 2 shows an estimation principle of the solenoid supply current based on the battery voltage monitoring described above for the interrupt processing executed in the interrupt processing unit 229. Next, referring to FIG. The current estimation principle will be described in detail.

  The interrupt processing unit 229 first extracts the battery voltage every “480 μsec” during the operation of the microcomputer 220 that the main routine related to feedback control or the like circulates at a certain time, for example, “6 msec”. The sampling value is A / D converted. Then, the maximum value and the minimum value between the battery cycles extracted every “480 μsec” and “6 msec” as the above-described circulation period are selected as the maximum value VBmax and the minimum value VBmin of the battery voltage, respectively. Note that the maximum value VBmax and the minimum value VBmin of the battery voltage are values that are gradually updated every cycle of “6 msec”.

  After the maximum value VBmax and the minimum value VBmin of the battery voltage are selected, the minimum value VBmin and the maximum value VBmax are obtained from each sampling value (A / D conversion value) SVBn in the subsequent cycle of the battery voltage. Are respectively divided to obtain the voltage drop rate and the voltage rise rate at that time. Incidentally, these values correspond to fluctuations in the supply current estimated each time. In addition, the current is monitored each time, ie, “6 msec” from each of the minimum holding current Imin and the output IC maximum guaranteed current Imax, which are constant values (measured at time t1 in FIG. 2). By dividing the current (this is referred to as the reference current Is), the risk with respect to the minimum holding current Imin and the risk with respect to the output IC maximum guaranteed current Imax are obtained for each circulation cycle.

  Incidentally, in FIG. 2, when the battery voltage SVBn sampled at the time t2 takes a transition as illustrated in FIG. 2A with respect to the maximum value VBmax of the battery voltage selected in the immediately preceding cycle, As shown in FIG. 2B, it is shown that the supply current to the solenoid estimated on the basis of the voltage drop rate is less than the minimum holding current Imin. That is, in this case, it can be said that the voltage drop rate (SVBn / VBmax) at the time point t2 is lower than the risk (Imin / Is) with respect to the minimum holding current Imin at the same point (the risk is high). . In general, since the response of the current is delayed with respect to the voltage fluctuation, if the increase of the duty ratio is corrected at the time point t2, it is possible to prevent the supply current to the solenoid from falling below the minimum holding current Imin in advance. I can expect that.

  This also applies to the output IC maximum guaranteed current Imax, and the voltage increase rate (SVBn / VBmin) at a certain point in time for the interrupt is the degree of danger with respect to the output IC maximum guaranteed current Imax at that time. When (Imax / Is) is exceeded (the risk is high), if the duty ratio is reduced and corrected at that time, the supply current to the solenoid is prevented from exceeding the output IC maximum guaranteed current Imax in advance. It can be expected to be possible.

Hereinafter, 480 μm executed by the interrupt processing unit 229 based on such a principle.
Interrupt processing every sec will be described with reference to FIGS. FIG. 3 shows an interrupt process executed when the battery voltage tends to decrease, and FIG. 4 shows an interrupt process executed when the battery voltage tends to increase.

  As shown in FIG. 3, in this interrupt process, first, as the process of step s101, the maximum value VBmax of the battery voltage in the cycle (“6 msec”) immediately before the microcomputer 220 is selected. At this time, the monitor value of the current flowing in the solenoids 101 to 104 within the circulation period is also stored in the appropriate memory in the microcomputer 220 as the reference current Is.

  When the battery voltage maximum value VBmax and the reference current Is are stored in this manner, the battery voltage sampling value SVBn at that time is read as the process of step s102, and the voltage drop rate (SVBn / Vmax) and the minimum hold are stored. A comparison based on the following equation (1) is performed with the degree of risk (Imin / Is) for the current Imin.

(SVBn / VBmax) <(Imin / Is) (1)

As a result of this comparison, when it is determined that the expression (1) is not satisfied, that is, it is determined that the estimated supply current to the solenoid is less than the minimum holding current Imin, the interrupt processing is Once terminated. As a result of the comparison, when it is determined that the above formula (1) is satisfied, that is, the estimated supply current to the solenoid is less than the minimum holding current Imin, the next step The process of s103 is executed.

  In the process of step s103, a process of increasing and correcting the duty ratio is performed so that the duty ratio compensated for temperature by the temperature compensation circuit (KT) 223b becomes a duty ratio for starting current command, for example. Is done.

  Next, as shown in FIG. 4, in this interrupt process, first, as the process of step s201, the minimum value VBmin of the battery voltage in the cycle (“6 msec”) immediately before the microcomputer 220 is selected. At this time, the monitor value of the current flowing in the solenoids 101 to 104 within the circulation period is also stored in the appropriate memory in the microcomputer 220 as the reference current Is.

  When the battery voltage minimum value VBmin and the reference current Is are stored in this way, the battery voltage sampling value SVBn at that time is read as the process of step s202, and the voltage drop rate (SVBn / Vmin) and the output IC are read. A comparison based on the following equation (2) is performed with the degree of risk (Imax / Is) for the maximum guaranteed current Imax.

(SVBn / VBmin)> (Imax / Is) (2)

As a result of this comparison, when it is determined that the expression (2) is not satisfied, that is, it is determined that there is a low risk that the estimated supply current to the solenoid exceeds the output IC maximum guaranteed current Imax, the interrupt processing is performed. Is temporarily terminated. Further, as a result of the comparison, when it is determined that the above formula (2) is satisfied, that is, there is a high risk that the estimated supply current to the solenoid exceeds the output IC maximum guaranteed current Imax, The process of step s203 is executed.

In the processing of step s203, this becomes a duty ratio that can further suppress the supply current to the solenoid below the output IC maximum guaranteed current Imax with respect to the duty ratio that has been temperature compensated by the temperature compensation circuit (KT) 223b. In this way, a process for reducing and correcting the duty ratio is executed.

These interrupt processes by the interrupt processing unit 229 are executed on condition that the switch 227 (FIG. 1) is turned on.
As described above, according to the solenoids 101 to 104 according to the present embodiment, the following effects can be obtained.

  (1) The transition of the current supplied to the solenoids 101 to 104 is estimated based on the variation rate of the battery voltage, and the duty ratio of the duty signal applied to the solenoids 101 to 104 is calculated based on the estimated transition of the current. I decided to correct it. For this reason, even if the battery voltage fluctuates, the current supplied to the solenoids 101 to 104 can be appropriately maintained at the target current each time. As a result, the current supplied to the plurality of solenoids 101 to 104 to be controlled can be controlled with high reliability. As a result, the drive is also controlled with high reliability. Will be able to.

  (2) Moreover, since the transition of the current that follows this is estimated on the basis of the variation rate of the battery voltage, even if there is a period during which the current flowing through the solenoids 101 to 104 cannot be monitored, The current supplied to the solenoids 101 to 104 can be controlled without being affected by the influence.

  (3) The interruption process including the extraction (sampling) of the battery voltage is executed every “480 μsec” which is sufficiently shorter than “6 msec” which is the circulation cycle of the microcomputer 220. As a result, even when the battery voltage fluctuates temporarily, it is possible to correct the duty ratio with high accuracy in accordance with the fluctuation rate of the battery voltage in each case, which is supplied to the solenoids 101 to 104. Current can be controlled with higher accuracy.

In addition, the said embodiment can also be implemented with the following forms.
The duty ratio for compensating for the temperature change of the solenoids 101 to 104 is added to the duty ratio mapped from the target current, but the temperature change of the solenoids 101 to 104 can be ignored, or other temperature compensation means May be omitted from the temperature compensation function by the temperature change monitoring unit 223a and the temperature compensation circuit (KT) 223b.

  A value such as “6 msec”, which is the circulation cycle of the microcomputer 220, or “480 μsec”, which is the interrupt cycle by the interrupt processing unit 229, is merely an example. In other words, at least the interrupt cycle may be a time that can absorb the response delay of the supply current to the solenoids 101 to 104 with respect to the fluctuation of the battery voltage, and the circulatory cycle of the microcomputer 220, that is, the feedback cycle based on the monitoring of the current. However, it is sufficient if the maximum value VBmax and the minimum value VBmin can be selected from the battery voltage in each case.

  -The suitability of the current supplied to the solenoids 101 to 104 is compared with the voltage drop rate (SVBn / VBmax) and the danger level (Imin / Is) for the minimum holding current, or the voltage rise rate (SVBn / VBmin) and output. The determination was made based on a comparison with the degree of risk (Imax / Is) for the IC maximum guaranteed current. However, the determination is not limited to this, and the determination may be performed based on a comparison between a voltage drop rate or a voltage rise rate and an empirically set threshold value. In this case, the threshold value may be a fixed value or a value that can be changed according to the environment.

  The interrupt processing unit 229 executes both the interrupt process of FIG. 3 and the interrupt process of FIG. 4 as the interrupt process, but may be configured to execute only one of these interrupt processes.

  In the above embodiment, the case where the feedback control system by the microcomputer that monitors the current supplied to the solenoids 101 to 104 and maintains the target current each time is applied is exemplified. Application to a forward control system is also possible. That is, while monitoring the battery voltage, the supply current to the solenoid caused by the variation in the monitored battery voltage can be estimated, and the duty ratio can be corrected in such a manner that the variation in the estimated supply current is suppressed. I just need it.

  In the above embodiment, the case where the solenoid control device according to the present invention is applied to a brake control device including an actuator structure integrated with a control unit (ECU) is illustrated. However, the present invention is not limited to such a brake control device. The present invention can be applied to any apparatus provided with the above. Further, the application target is not limited to the control unit (ECU) integrated actuator structure.

DESCRIPTION OF SYMBOLS 100 ... Actuator part 101-104 ... Solenoid, 200 ... Control part, 210 ... Solenoid relay, 220 ... Microcomputer, 221 ... Target current setting part, Current-duty (Duty) conversion map 222, 223a ... Temperature change monitoring part, 223b ... temperature compensation circuit, 224 ... target current monitoring part, 225 ... A / D conversion part, 226 ... digital filter, 227 ... virtual switch, 228 ... PI controller, 229 ... interrupt processing part, 230 ... output IC, 231 ... PWM Drive unit, 232... Transistor (P channel type FET), 233... Transistor (N channel type FET), 234... Voltage / current conversion unit, 300.

Claims (8)

In a solenoid control device that performs duty control on the supply current to the solenoid based on the battery voltage and corrects the duty ratio for duty control so that the supply current to the solenoid is maintained at the target current in each case,
While monitoring the battery voltage, the fluctuation of the supply current to the solenoid caused by the fluctuation of the monitored battery voltage is estimated, and the duty ratio is corrected in such a manner that the fluctuation of the estimated supply current is suppressed. A solenoid control device. A feedback control system that feedback-corrects the duty ratio by a microcomputer so as to be maintained at a target current while monitoring the supply current to the solenoid controlled by the duty control, the battery voltage monitor, and the battery voltage The fluctuation of the supply current to the solenoid based on the monitoring of the current and the correction of the duty ratio with respect to the fluctuation of the estimated supply current are executed as interrupt processing by the microcomputer added to the feedback path of the feedback control system. The solenoid control device according to claim 1. The minimum current value at which the value of the supply current to the solenoid estimated from the rate of decrease of the battery voltage within a certain time during which the interrupt processing is repeated can hold the driving state of the solenoid at a minimum. The solenoid control device according to claim 2, which is performed as an increase correction of the duty ratio when the minimum holding current is not satisfied. The determination that the value of the current supplied to the solenoid, which is estimated from the rate of decrease of the battery voltage, is less than the minimum holding current is the maximum value of the battery voltage sampled within the predetermined time when the interrupt process is repeated. When VBmax, similarly, the sampling value after the maximum value of the battery voltage is SVBn, the monitor value of the current supplied to the solenoid at each fixed time is Is, and the minimum holding current is Imin,

(SVBn / VBmax) <(Imin / Is)

The solenoid control device according to claim 3, wherein the solenoid control device is performed when the following relationship is satisfied. The interrupt process can guarantee the operation of the output IC that controls the drive of the solenoid, based on the value of the supply current to the solenoid estimated from the rate of increase of the battery voltage within a certain time during which the interrupt process is repeated. The solenoid control device according to claim 2, which is performed as a reduction correction of the duty ratio when the output IC maximum guaranteed current which is a maximum current value is reached. The determination that the value of the current supplied to the solenoid estimated from the rate of increase of the battery voltage reaches the output IC maximum guaranteed current is the minimum value of the battery voltage sampled within the predetermined time when the interrupt process is repeated VBmin, similarly, the sampling value after the minimum value of the battery voltage is SVBn, the monitor value of the current supplied to the solenoid at each fixed time is Is, and the output IC maximum guaranteed current is Imax,

(SVBn / VBmin)> (Imax / Is)

The solenoid control device according to claim 5, wherein the solenoid control device is performed when the following relationship is satisfied. The duty ratio that is feedback-corrected in the feedback control system is compensated for a temperature change of the solenoid that is monitored based on the value of the current supplied to the monitored solenoid. The solenoid control device according to Item. The solenoid as a target of the duty control is a solenoid provided in each of a plurality of solenoid valves for hydraulic pressure control in a brake control device including a controller-integrated actuator structure. The solenoid control device according to 1.

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