JP5765572B2 - Solenoid energization control device - Google Patents

Description

  The present invention relates to an energization control device that controls a current of a solenoid.

  Conventionally, solenoids have been used for opening / closing control of electromagnetic valves and driving of actuators. Such energization control of the solenoid is performed by PWM control. There exists a thing of patent document 1 which shows a source | sauce below as such a technique.

  The current control device described in Patent Literature 1 includes a detection unit, an A / D conversion unit, a control unit, and an average current calculation unit. The detecting means detects the current actually flowing through the solenoid that is energized and controlled by the PWM signal generated at a constant period. The A / D conversion means converts the detection result into a digital value by the detection means at every preset A / D conversion cycle. The control means controls the duty ratio of the PWM signal so that the detected current value converted into a digital value by the A / D conversion means becomes the target current value. The average current calculation means calculates the average current value within a predetermined period by acquiring the detected current value for a predetermined period of the PWM signal and arithmetically averaging the acquired detected current value. The current control device controls the duty ratio of the PWM signal based on the calculated average current value and target current value.

Japanese Patent Laid-Open No. 11-308107

  In the technique described in Patent Document 1, the average current calculation means operates based on a clock signal generated by a dedicated oscillator. The A / D conversion means and the control means operate based on a clock signal generated by another oscillator different from the clock signal. That is, the A / D conversion means and the control means operate in synchronization with a clock signal from the same oscillator, and the average current calculation means depends on a clock signal from an oscillator different from the A / D conversion means and the control means. The A / D conversion means and the control means operate asynchronously. For this reason, when the clock signal of the A / D conversion means and the control means does not become an integral multiple of the clock signal of the average current calculation means, the timing for detecting the current flowing through the solenoid and the current related to the detected current There is a possibility that the timing of A / D conversion of the value and the timing of outputting the PWM signal are shifted. Accordingly, the solenoid cannot be properly energized.

  In view of the above problems, an object of the present invention is to provide a solenoid energization control device capable of appropriately energizing a solenoid while suppressing a shift between a timing of detecting a current flowing through the solenoid and a timing of outputting a PWM signal. Is to provide.

In order to achieve the above object, the characteristic configuration of the solenoid energization control device according to the present invention is as follows:
A current acquisition timer for measuring the time for determining the timing for acquiring the current value of the current flowing through the solenoid;
Based on the counting result of the current acquisition timer, the current value is set a predetermined number of times without synchronizing with the PWM signal within one cycle of the PWM signal that drives the switching element that controls energization of the solenoid. A current value acquisition unit to acquire;
A PWM control timer for measuring a time for defining a timing for outputting the PWM signal;
Based on the current value acquired within the one cycle, the current value for energizing the solenoid in the next cycle is calculated, and the switching element is energized in the next cycle based on the calculated current value. A PWM control unit that sets an energization time, and outputs a PWM signal corresponding to the set energization time based on a time measurement result of the PWM control timer;
A time value updating unit for updating the time value of the current acquisition timer based on the time measurement result of the PWM control timer;
It is in the point equipped with.

  With such a characteristic configuration, the current acquisition timer can be adjusted based on the PWM control timer. Accordingly, since it is possible to suppress a deviation between the timing of detecting the current flowing through the solenoid and the timing of outputting the PWM signal, it is possible to appropriately energize the solenoid.

  In addition, the time value update unit sets the time value of the current acquisition timer to a preset value when the time measurement result of the PWM control timer reaches a value that defines the timing for outputting the PWM signal. It is preferable to update.

  With such a configuration, the time value of the current acquisition timer can be adjusted in synchronization with the PWM control timer for each period of the PWM signal. Therefore, it is possible to suppress a deviation between the timing for detecting the current flowing through the solenoid and the timing for outputting the PWM signal.

  Alternatively, the PWM control timer also counts a time that defines one cycle of the PWM signal, and the time value update unit determines that the time measurement result of the PWM control timer is equal to one cycle of the PWM signal. It is good also as a structure which updates the time-measurement value of the said current acquisition timer to the value calculated using the preset value whenever it becomes the value equally divided by the frequency | count of acquisition.

  With such a configuration, the time value of the current acquisition timer can be adjusted in synchronization with the PWM control timer every time the solenoid current is detected. Therefore, it is possible to suppress a deviation between the timing for detecting the current flowing through the solenoid and the timing for outputting the PWM signal.

  Further, it is preferable that the current control period for setting the energization time of the switching element is configured not to be shortened by the time value update unit.

  With such a configuration, the current control period can be provided with certainty, so that the energization control of the solenoid can be appropriately performed.

  In addition, after the final current value in one cycle of the PWM signal is acquired, the first current value in the next cycle of the PWM signal is acquired in the next one cycle of the PWM signal. It is preferable that the current value for energizing the solenoid is calculated, the energization time for energizing the switching element is set in the next cycle of the PWM signal, and the next cycle of the PWM signal is started. It is.

  With such a configuration, it is possible to set the energization time for energizing the switching element while suppressing the difference between the timing for detecting the current flowing through the solenoid and the timing for outputting the PWM signal. Therefore, the energization control of the solenoid can be appropriately performed.

  Further, a number counting unit that counts the number of times the current value acquisition unit acquires the current value within one cycle of the PWM signal is provided, and the PWM control unit includes the current value within one cycle of the PWM signal. When the number of times of acquisition of the switching element is less than the preset number, it is preferable to set the energization time for energizing the switching element in the next cycle of the PWM signal to the same energization time as this time.

  With such a configuration, even when the current value cannot be obtained a preset number of times and the current flowing to the solenoid cannot be calculated in the period of the next PWM signal, the current period is provisionally set in the next period. The switching element can be energized.

It is the figure which showed typically schematic structure of the electricity supply control apparatus of a solenoid. It is a time chart concerning energization control of a solenoid. It is the figure which showed typically about correction | amendment of the time value which concerns on 1st Embodiment. It is the figure which showed typically about correction | amendment of the time value which concerns on 1st Embodiment. It is the figure which showed typically about correction | amendment of the time value which concerns on 1st Embodiment. It is a flowchart regarding correction | amendment of the time value which concerns on 1st Embodiment. It is the figure which showed typically about correction | amendment of the time value which concerns on 2nd Embodiment. It is a flowchart regarding correction | amendment of the time value which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail. The solenoid energization control device (hereinafter referred to as “energization control device”) 100 according to the present invention synchronizes the timing for acquiring the current value of the current flowing through the solenoid and the timing for outputting the PWM signal for controlling energization of the solenoid. It has a function to let you. Such a solenoid is used for, for example, opening / closing control of an electromagnetic valve and driving of an actuator. The energization control apparatus 100 controls such a solenoid.

[First Embodiment]
A first embodiment of the energization control device 100 will be described. FIG. 1 schematically shows a configuration of an energization control device 100 that controls energization of the solenoid 50. FIG. 2 shows an example of a time chart of processing by the energization control device 100. As shown in FIG. 1, the energization control device 100 includes functions of a current acquisition timer 10, a current value acquisition unit 11, a PWM control timer 20, a PWM control unit 21, a frequency count unit 31, and a time value update unit 41. It is configured with a part. Each functional unit includes the above-described functional units for performing various processes for energizing the solenoid 50 with a CPU as a core member, and is constructed by hardware and / or software.

  The current acquisition timer 10 measures the time that defines the timing for acquiring the current value of the current flowing through the solenoid 50. Although details will be described later, the current value acquisition unit 11 described later detects a current flowing through the solenoid 50 at every predetermined period TI, as shown in FIG. The current acquisition timer 10 corresponds to a timer that measures time at a frequency corresponding to the predetermined period TI. In the present embodiment, as shown in FIG. 2B, the current acquisition timer 10 measures time while reducing the time value from a predetermined value (eg, “XI”) to 0 at a predetermined period TI. When the time value reaches 0, the time is reset, and the time is again reduced from the predetermined value to 0. The current acquisition timer 10 repeats such timekeeping.

  Based on the count result of the current acquisition timer 10, the current value acquisition unit 11 acquires a current value a predetermined number of times within one cycle of the PWM signal that drives the switching element 51 that controls energization of the solenoid 50. . The solenoid 50 has one end connected to the switching element 51 and the other end connected to the power source V. The switching element 51 can be configured using, for example, an FET. In this case, the source terminal is grounded, and the solenoid 50 is connected to the drain terminal. A PWM signal having a predetermined frequency is transmitted to the gate terminal from a PWM control unit 21 described later. Thereby, the switching element 51 is driven.

  The current detection unit 11A connected to the current value acquisition unit 11 is provided between the source terminal and the ground. Thereby, it is possible to detect the current flowing through the solenoid 50 when the switching element 51 is turned on. The current flowing through the solenoid 50 is shown in FIG.

  The current detection unit 11A detects a current value for a preset number of times within one period of the PWM signal (“TP” in FIG. 2G). Such a current value detection cycle corresponds to the cycle TI of the current acquisition timer 10 described above. In the present embodiment, the number of times the current value is detected within one PWM period is four. The current values for four times detected in this way are transmitted to the current value acquisition unit 11 each time they are detected. The current value acquisition unit 11 performs A / D conversion on the detected current value, and acquires a digitally converted current value.

  The number of times that the current value acquisition unit 11 acquires a current value within one cycle of the PWM signal is counted by the number counting unit 31. Such an acquisition count is shown in FIG. When the count unit 31 counts up to four times, the count value is reset and starts counting once again.

  The PWM control timer 20 measures the time that defines the timing for outputting the PWM signal. As described above, the PWM signal has a predetermined frequency. In the present embodiment, although details will be described later, the PWM control unit 21 outputs a PWM signal having a frequency corresponding to a predetermined period TP as shown in FIG. The PWM control timer 20 corresponds to a timer that measures the time until the PWM signal is switched from on-duty to off-duty and the time until the PWM signal is switched from off-duty to on-duty. In the present embodiment, as shown in FIG. 2 (e), the current acquisition timer 10 reduces the time until the PWM signal is switched from on-duty to off-duty from a predetermined value (for example, “XP1”) to 0. After measuring the time, the time until switching from the off-duty to the on-duty is measured while decreasing from a predetermined value (for example, “XP2”) to zero. The PWM control timer 20 repeats such timekeeping.

  The PWM control unit 21 calculates a current value for energizing the solenoid 50 in the next one cycle of the PWM signal based on the current value acquired in one cycle of the PWM signal, and the next based on the calculated current value. The energization time during which the switching element 51 is energized is set in one cycle, and a PWM signal corresponding to the energization time set based on the timing result of the PWM control timer 20 is output. As described above, the current value acquisition unit 11 acquires a current value digitally converted four times within one cycle of the PWM signal. The PWM control unit 21 calculates a current value for energizing the solenoid 50 in the next cycle of the PWM signal using the current values for the four times. This calculation is performed based on the opening degree of the solenoid valve opened by the solenoid 50 and the drive command value of the actuator. Since such calculation is well known, description thereof is omitted.

  The PWM control unit 21 sets the energization time based on the current value obtained by calculation in this way. This energization time corresponds to the on-duty of the PWM signal. The PWM control unit 21 corresponds to the output timing of the PWM signal when the time measurement result of the PWM control timer 20 (time value of time until switching from the off duty to the on duty) becomes 0 (FIG. 2 (f)). The PWM signal is switched from the low level to the high level (see FIG. 2G).

  Here, as shown in FIG. 2, the period (period TP) of the PWM signal and the period (period TI) for acquiring the solenoid current are different from each other in phase. Such a phase shift cannot be made zero due to the specification of the solenoid 50. However, when the solenoid 50 is energized, there may be a problem if the phase shift becomes too large or too small. Therefore, the time value update unit 41 of the energization control apparatus 100 updates the time value of the current acquisition timer 10 based on the time measurement result of the PWM control timer 20.

  In the present embodiment, the time value update unit 41 sets the time value of the current acquisition timer 10 in advance when the time measurement result of the PWM control timer 20 reaches a value that defines the timing for outputting the PWM signal. Update to value. Here, there is a phase shift between the period (period TP) measured by the PWM control timer 20 and the period (period TI) measured by the current acquisition timer 10 as described above, and this deviation is set in advance. ing. In this embodiment, such a preset phase shift is C0. In this embodiment, the case where the value that defines the timing for outputting the PWM signal is a time point when the time measured until switching from the off duty to the on duty becomes zero. Therefore, the PWM control unit 21 switches the PWM signal when the measured time value from the off-duty to the on-duty becomes zero in the timing result of the PWM control timer 20. Therefore, the time value updating unit 41 updates the time value of the current acquisition timer 10 to C0 when the time measurement result of the PWM control timer 20 becomes zero.

  The update of the current acquisition timer 10 will be specifically described with reference to FIG. FIG. 3 shows the time measured value (see FIG. 3A) of the PWM control timer 20 in the vicinity of t9 in FIG. 2 and the time measured value of the current acquisition timer 10 (see FIG. 3B). is there. Here, in this example, it is assumed that the time value of the current acquisition timer 10 at t9 is C1. When the time value (a) of the PWM control timer 20 becomes zero (# 01), the time value update unit 41 updates the preset time difference of the time value of the current acquisition timer 10 to C0 (#). 02). The current acquisition timer 10 then counts from the updated C0 to zero. Thus, the time value of the current acquisition timer 10 can be adjusted with respect to the time value of the PWM control timer 20, so that a preset phase shift can be maintained.

  For example, as shown in FIG. 4, even if the time value of the current acquisition timer 10 when the time value (a) of the PWM control timer 20 becomes zero is smaller than C0, When the time value (a) of the timer 20 becomes zero (# 01), the time value update unit 41 updates the time difference of the current acquisition timer 10 to C0, which is a preset phase shift (# 02). ). As a result, the current acquisition timer 10 counts from the updated C0 to zero, so that a preset phase shift can be maintained.

  Thus, the time value update unit 41 compares the time value of the current acquisition timer 10 when the time value (a) of the PWM control timer 20 becomes zero with a preset phase shift C0. Since it is updated without any changes, the processing load can be reduced.

  As shown in FIG. 5, even when the time value C1 of the current acquisition timer 10 when the time value (a) of the PWM control timer 20 becomes zero happens to be C0, the PWM control timer 20 When the time value (a) of the current value becomes zero (# 01), the time value update unit 41 updates the time difference of the current acquisition timer 10 to C0, which is a preset phase shift (# 02). It is also possible. In such a case, it is not necessary to determine whether or not the phase shift is C0, so that the processing load can be reduced.

  Here, returning to FIG. 2, a current control period I0 for setting the energization time of the switching element 51 is provided so that the PWM control unit 21 controls the current value of the next cycle of the PWM signal. Since the current control period I0 is necessary for properly energizing the solenoid 50, it is configured not to be shortened by the time value updating unit 41. Therefore, the time value update unit 41 updates the time value of the current acquisition timer 10, and at least the current control period I0 can be secured even if the time value is smaller than the original value.

  Here, depending on the time value of the current acquisition timer 10, the number of times the current value acquisition unit 11 acquires the current value within one cycle of the PWM signal may be less than the preset number. In such a case, the PWM control unit 21 cannot calculate the current value of the current that is energized to the solenoid 50 in the next cycle, so the energization time for energizing the switching element 51 in the next cycle of the PWM signal. The same energization time as this time is set. As a result, the solenoid 50 can be energized for the next one cycle. Therefore, the problem that the valve remains closed and the actuator does not drive is eliminated.

  In the present embodiment, after the last current value in one cycle of the PWM signal is acquired, the first current value in the next cycle of the PWM signal is acquired until the first current value in the next cycle of the PWM signal. A current value for energizing the solenoid 50 in a cycle is calculated, and an energization time for energizing the switching element 51 is set in the next cycle of the PWM signal, and the next cycle of the PWM signal is started. That is, as shown in FIG. 2, between the time t6 at which the final current value within one period of the PWM signal is acquired and the time t10 at which the first current value within the next period of the PWM signal is acquired, A current control period I0 (between t7 and t8) in which a current value to be energized in the next period is provided, an energization time for energizing the switching element 51 is set, and energization is started by the PWM control unit 21. (T9).

  Next, processing by the energization control apparatus 100 will be described using the flowchart of FIG. First, a PWM signal is output from the PWM control unit 21 (step # 01). This output is performed based on an energization start command from the host system, for example. In synchronization with the output of the PWM signal, the PWM control timer 20 starts measuring time (step # 02).

  11 A of current detection parts detect the current which flows into the solenoid 50 which predetermined time passes after the output of the PWM signal by the PWM control part 21, and the current value digitally converted based on the current value which the current value acquisition part 11 detected Is acquired (step # 03). The number counting unit 31 sets the number n of current value acquisitions by the current value acquiring unit 11 to 1 (step # 04). The current acquisition timer 10 starts measuring time (step # 05).

  At this time, if the time value of the PWM control timer 20 is zero (step # 06: No), the PWM control unit 21 sets the current value to be energized to the solenoid 50 in the next PWM signal cycle to the solenoid current cycle. 50 is set to the current value energized 50 (step # 07). Thereafter, the processing is continued from step # 01.

  In step # 06, if the time value of the PWM control timer 20 is not zero (step # 06: Yes) and the time value of the current acquisition timer 10 is not zero (step # 08: No), the process is performed. Deferred. On the other hand, if the time value of the current acquisition timer 10 is zero (step # 08: Yes), the current value acquisition unit 11 acquires the current value (step # 09). As a result, the number counting unit 31 adds 1 to the number n of current value acquisitions by the current value acquiring unit 11 (step # 10).

  If the number n of current value acquisitions by the current value acquisition unit 11 counted by the number counting unit 31 is not 4 (step # 11: No), the time value of the current acquisition timer 10 is reset (step # 12). On the other hand, if the number n of current value acquisitions by the current value acquisition unit 11 counted by the number counting unit 31 is 4 (step # 11: Yes), the time measurement value of the current acquisition timer 10 is reset and time measurement is started. (Step # 12). Then, the number counting unit 31 sets the number n of current value acquisitions to 1 (step # 13).

  As a result of the processing so far, the current value for four times in one cycle of the PWM signal has been acquired, the PWM control unit 21 calculates the current value for energizing the solenoid 50 in the next one cycle (step # 14), and switching. The energization time for energizing the element 51 is set (step # 15).

  In this state, if the measured value of the PWM control timer 20 becomes zero (step # 16: Yes), the PWM control unit 21 outputs a PWM signal (step # 17). As a result, the time value of the PWM control timer 20 is reset (step # 18). Thereafter, the PWM control timer 20 starts measuring time (step # 19).

  The time value updating unit 41 sets the time value of the current acquisition timer 10 when the time value of the PWM control timer 20 becomes zero to a preset value t0 (step # 20). Thereafter, the processing is continued from step # 06.

  In step # 16, if the time value of the PWM control timer 20 is not zero (step # 16: No) and the time value of the current acquisition timer 10 is not zero (step # 21: No), the process is suspended. The On the other hand, if the time measured value of the current acquisition timer 10 is also zero (step # 21: Yes), the processing is continued from step # 20.

  As described above, the current supply control device 100 can adjust the current acquisition timer 10 based on the PWM control timer 20. Accordingly, since it is possible to suppress a deviation between the timing for detecting the current flowing through the solenoid 50 and the timing for outputting the PWM signal, it is possible to appropriately energize the solenoid 50.

[Second Embodiment]
Next, a second embodiment of the energization control device 100 according to the present invention will be described. In the first embodiment, when the time measurement value updating unit 41 determines that the time measurement result of the PWM control timer 20 is a value that defines the timing for outputting the PWM signal, the time measurement value of the current acquisition timer 10 is set in advance. It has been described as updating to a set value. The energization control apparatus 100 according to the present embodiment is different from the first embodiment in the timing for updating the time value of the current acquisition timer 10. Since the configuration of the energization control device 100 is the same as the configuration shown in FIG. 1 shown in the first embodiment, a description thereof will be omitted, and the following description will focus on the differences.

  The time measurement value update unit 41 according to the present embodiment updates the time measurement result of the PWM control timer 20 every time the PWM signal is equal to one cycle of the PWM signal divided by the number of times the current value is acquired. The PWM control timer 20 measures the time that defines the timing for outputting the PWM signal as described above. In this embodiment, the PWM control timer 20 also measures the time that defines one period of the PWM signal. When one cycle of the PWM signal is TP and the number of times the current value of the solenoid 50 is acquired by the current value acquiring unit 11 in the one cycle is four, the time value updating unit 41 according to the present embodiment performs PWM control. Every time the measured value of the timer 20 becomes TP / 4 × n (where n = 1, 2, 3, 4), the measured value of the current acquisition timer 10 is updated. Therefore, in this embodiment, the time value of the current acquisition timer 10 is updated four times in one cycle of the PWM signal. Since one period of the PWM signal is set in advance, it can be easily calculated and obtained.

  The time value update unit 41 updates the time value of the current acquisition timer 10 to a value calculated using a preset value. Update of the current acquisition timer 10 according to the present embodiment will be described with reference to FIG. The PWM signal for one period (period TP) is shown in the uppermost part of FIG. It is assumed that the energization control device 100 starts energization control of the solenoid 50 at t1.

  In this case, the current acquisition timer 10 measures the time while subtracting from a value (for example, “X1”) corresponding to ¼ of the period TP of the PWM signal to zero. When ¼ of the period TP elapses from t1 and reaches t21, the time measurement value update unit 41 calculates a value (referred to as “X2”) that the current acquisition timer 10 measures in the next period at time t21. . This X2 is obtained by the following equation (1).

ただし、Ｃ１はｔ２１の時点での電流取得用タイマ１０の計時値であり、Ｃ０は予め設定されている位相のずれである。また、ｋは予め設定されたゲインである。例えば１未満の値にすると、電流取得用タイマ１０の誤差をいち早く収束することが可能となる。

However, C1 is the time value of the current acquisition timer 10 at time t21, and C0 is a preset phase shift. K is a preset gain. For example, when the value is less than 1, the error of the current acquisition timer 10 can be quickly converged.

  In this way, the time value updating unit 41 calculates the value that the current acquisition timer 10 measures in the next period at t21. Then, the time value of the current acquisition timer 10 at t3 is updated to X2 obtained by the calculation. Thereafter, the current acquisition timer 10 measures the time while subtracting from a value (X2) calculated using preset values (C0 and k) to zero. At t22, the time measurement value update unit 41 further calculates a value (referred to as “X3”) that the current acquisition timer 10 measures in the next period. This X3 is calculated | required by the following (2) Formula.

ただし、Ｃ２はｔ２２の時点での電流取得用タイマ１０の計時値である。Ｃ０及びｋについては、上述の（１）式と同様の値が用いられる。

However, C2 is the time value of the current acquisition timer 10 at time t22. About C0 and k, the same value as the above-mentioned (1) formula is used.

Hereinafter, similarly, the value measured at t6 (referred to as “X4”), and further the value measured at t10 in the next period of the PWM signal (referred to as “X5”) are expressed using the following formulae: Calculate.

  As described above, the time value updating unit 41 according to the present embodiment sequentially calculates the value measured by the current acquisition timer 10 in the next period. This makes it possible to relatively reduce the error of the current acquisition timer 10 with reference to the PWM control timer 20. Therefore, it is possible to synchronize PWM control and current value acquisition.

  Next, processing by the energization control apparatus 100 according to the present embodiment will be described using the flowchart of FIG. First, a PWM signal is output from the PWM control unit 21 (step # 01). This output is performed based on an energization start command from the host system, for example. In synchronization with the output of the PWM signal, the PWM control timer 20 starts measuring time (step # 02).

  11 A of current detection parts detect the current which flows into the solenoid 50 which predetermined time passes after the output of the PWM signal by the PWM control part 21, and the current value digitally converted based on the current value which the current value acquisition part 11 detected Is acquired (step # 03). The number counting unit 31 sets the number n of current value acquisitions by the current value acquiring unit 11 to 1 (step # 04). The current acquisition timer 10 starts measuring time (step # 05).

At this time, if the time value of the PWM control timer 20 is n / 4 times the period of the PWM signal (step # 06: Yes), the time value update unit 41 sets the time value of the current acquisition timer 10 at that time. In the next period, the value counted by the current acquisition timer 10 is calculated (step # 07).
On the other hand, in step # 06, if the measured value of the PWM control timer 20 has not reached n / 4 times the period of the PWM signal (step # 06: No), the process is suspended.

  If the time value of the current acquisition timer 10 is zero (step # 08: Yes), the current value acquisition unit 11 acquires the current value (step # 09). As a result, the number counting unit 31 adds 1 to the number n of current value acquisitions by the current value acquiring unit 11 (step # 10).

  The time value update unit 41 updates the time value of the current acquisition timer 10 to the value calculated as described above (step # 11). At this time, the current control period in which the current value acquisition unit 11 sets the energization time of the switching element 51 is not shortened. If the current value acquisition count n by the current value acquisition unit 11 counted by the count counter 31 is not 4 (step # 12: No), the processing is continued from step # 05. On the other hand, if the number n of current value acquisitions by the current value acquisition unit 11 counted by the number counting unit 31 is 4 (step # 12: Yes), the time measurement value of the current acquisition timer 10 is reset and time measurement is started. (Step # 13). Then, the number counting unit 31 sets the current value acquisition number n to 1 (step # 14).

  As a result of the processing so far, current values for four times in one period of the PWM signal have been acquired, the PWM control unit 21 calculates a current value for energizing the solenoid 50 in the next one period (step # 15) and switching. The energization time for energizing the element 51 is set (step # 16).

  In this state, if the measured value of the PWM control timer 20 becomes zero (step # 17: Yes), the PWM control unit 21 outputs a PWM signal (step # 18). As a result, the time value of the PWM control timer 20 is reset (step # 19). Thereafter, the PWM control timer 20 starts measuring time (step # 20), and the processing is continued from step # 06.

  In step # 17, if the time value of the PWM control timer 20 is not zero (step # 17: No) and the time value of the current acquisition timer 10 is not zero (step # 21: No), the process is suspended. The On the other hand, if the time measured value of the current acquisition timer 10 is also zero (step # 21: Yes), the processing is continued from step # 03.

  Thus, since the energization control apparatus 100 can synchronize the PWM control of the switching element 51 and the acquisition of the current value energized to the solenoid 50, it is possible to appropriately energize the solenoid 50.

[Other Embodiments]
In the first embodiment, the time value updating unit 41 preliminarily sets the time value of the current acquisition timer 10 when the time measurement result of the PWM control timer 20 becomes a value that defines the timing for outputting the PWM signal. In the second embodiment, the time measurement value update unit 41 updates the time measurement result of the PWM control timer 20 to a value obtained by equally dividing one period of the PWM signal by the number of times the current value is acquired. It has been described that the time value of the current acquisition timer 10 is updated to a value calculated using a preset value each time. However, the scope of application of the present invention is not limited to this. For example, the time value updating unit 41 counts the time value of the current acquisition timer 10 every time the time measurement result of the PWM control timer 20 becomes a value obtained by equally dividing one period of the PWM signal by the number of times the current value is acquired. It is also possible to adopt a configuration in which is updated to a preset value. In addition, the time value update unit 41 uses a value set in advance as the time value of the current acquisition timer 10 when the time measurement result of the PWM control timer 20 reaches a value that defines the timing for outputting the PWM signal. Of course, it is also possible to adopt a configuration in which the values calculated in this way are updated.

  In the above embodiment, the current control period for setting the energization time of the switching element 51 has been described as being configured so as not to be shortened by the time value updating unit 41. However, the scope of application of the present invention is not limited to this. It is naturally possible to configure the time value update unit 41 to shorten the current control period.

  In the above embodiment, the PWM control unit 21 energizes the switching element 51 in the next one cycle of the PWM signal when the number of current value acquisitions within one cycle of the PWM signal is less than the preset number of times. Is described as being set to the same energization time as this time. However, the scope of application of the present invention is not limited to this. The PWM control unit 21 can also set the energization time set in advance when the number of current value acquisitions is less than the preset number within one cycle of the PWM signal.

  The present invention can be used in an energization control device that controls the current of a solenoid.

DESCRIPTION OF SYMBOLS 10: Current acquisition timer 11: Current value acquisition unit 20: PWM control timer 21: PWM control unit 31: Count count unit 41: Timekeeping value update unit 50: Solenoid 51: Switching element 100: Energization control device (energization of solenoid) Control device)

Claims (6)

A current acquisition timer for measuring the time for determining the timing for acquiring the current value of the current flowing through the solenoid;
Based on the counting result of the current acquisition timer, the current value is set a predetermined number of times without synchronizing with the PWM signal within one cycle of the PWM signal that drives the switching element that controls energization of the solenoid. A current value acquisition unit to acquire;
A PWM control timer for measuring a time for defining a timing for outputting the PWM signal;
Based on the current value acquired within the one cycle, the current value for energizing the solenoid in the next cycle is calculated, and the switching element is energized in the next cycle based on the calculated current value. A PWM control unit that sets an energization time and outputs a PWM signal corresponding to the set energization time based on a time measurement result of the PWM control timer;
A time value updating unit for updating the time value of the current acquisition timer based on the time measurement result of the PWM control timer;
A solenoid energization control device comprising:   The timekeeping value updating unit updates the timekeeping value of the current acquisition timer to a preset value when the timekeeping result of the PWM control timer reaches a value that defines the timing for outputting the PWM signal. The solenoid energization control device according to claim 1. The PWM control timer also measures the time defining one cycle of the PWM signal,
The timekeeping value update unit counts the timekeeping value of the current acquisition timer each time the timekeeping result of the PWM control timer is equal to one PWM signal period divided by the number of times the current value is acquired. The energization control device for a solenoid according to claim 1, wherein the value is updated to a value calculated using a preset value.   4. The solenoid energization control device according to claim 1, wherein a current control period for setting an energization time of the switching element is configured not to be shortened by the time value update unit. 5.   After the final current value in one cycle of the PWM signal is acquired, until the first current value in the next cycle of the PWM signal is acquired, the solenoid in the next cycle of the PWM signal. The current value for energizing is calculated, energization time for energizing the switching element is set in the next cycle of the PWM signal, and the next cycle of the PWM signal is started. The energization control device for the solenoid according to any one of the above. A number counting unit that counts the number of times the current value acquisition unit acquires the current value within one cycle of the PWM signal;
The PWM control unit sets an energization time for energizing the switching element in the next one cycle of the PWM signal when the number of acquisitions of the current value is less than a preset number of times within one cycle of the PWM signal. The energization control device for a solenoid according to any one of claims 1 to 5, wherein the energization time is set to be the same as that of the current time.

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