JP4378923B2 - Vehicle equipped with a battery charge / discharge current measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle including a battery charge / discharge current measuring device that measures a charge / discharge current of a battery with a current sensor.
[0002]
[Prior art]
A vehicle equipped with such a battery charge / discharge current measuring device is a vehicle equipped with a device for measuring the charging current and discharging current of the battery and monitoring the operating state of the battery.
The charging / discharging current of the battery mounted on the vehicle is roughly classified, and the current value to be measured varies greatly as the digit is different in the three states before engine start, engine start, and travel. ing.
Conventionally, in general, the current sensor used for measuring the charge / discharge current is a current sensor having a full-scale current value that can cover the maximum value of the charge / discharge current of the battery (discharge current value at the start of the engine). It is done.
However, when a current sensor having a large full-scale current value is used as described above, the resolution is lowered and the measurement accuracy in a relatively low current region is lowered.
[0003]
For this reason, as described in Patent Document 1, when energizing a large current identified based on the operation state of the starter, a method of estimating by calculation without using detection information of the current sensor, or Patent Document 2 As described above, when a large current identified based on the operation state of the starter is applied, a method of lowering the amplification factor of an amplifier that amplifies the output signal of the current sensor, or, as described in Patent Document 3, A method of changing the amplification factor of an amplifier that amplifies the output signal of the current sensor in accordance with the measured current value is considered.
However, for more accurate charge / discharge current measurement, the full-scale current is larger than the estimation based on the calculation as in Patent Document 1 or the method based on the subsequent circuit processing as in Patent Document 2 and Patent Document 3. It is desirable to have multiple current sensors with different values and measure the charge / discharge current of the battery in parallel with these multiple current sensors. The resolution can be secured.
[0004]
However, when measuring in parallel with multiple current sensors with different full-scale current values, it is not easy to select which current sensor output to obtain, especially for energy consumption and exhaust gas reduction. This is especially true when the charging / discharging current of the battery changes greatly in a relatively short time, such as a vehicle having a so-called idling stop function for stopping the engine in a waiting state.
For which current sensor output to select, select the output of a current sensor with a small full-scale current value, as in the digital multimeter's autorange function, and when that current sensor overflows, It is also possible to switch to a state where the output of a current sensor with a small full-scale current value is selected, but since the data at the time of switching is lost, it is practical when the charge / discharge current changes greatly and rapidly. Data will not be obtained.
For the above reasons, when using a plurality of current sensors having different full-scale current values, conventionally, the detected values of the plurality of current sensors are stored and stored in parallel, and the post- In addition, the method of selecting the output of the current sensor that is performing the optimal measurement at each measurement time point was employed.
[0005]
[Patent Document 1]
JP 2001-74786 A [Patent Document 2]
JP 2001-91602 A [Patent Document 3]
JP 2002-62341 A
[Problems to be solved by the invention]
Therefore, in the above conventional configuration, if the charge / discharge current of the battery is measured in real time, the measurement accuracy in a relatively low current range is lowered, and if it is attempted to ensure the measurement accuracy, data acquisition in real time is performed. In addition, post-processing of data is necessary.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle including a measuring device that can accurately measure a charging / discharging current of a battery in real time with a simple process.
[0007]
[Means for Solving the Problems]
A vehicle having a battery charge / discharge current measuring device that measures a charge / discharge current of a battery with a current sensor by providing the configuration according to claim 1, and a plurality of current sensors having different full-scale current values; A sensor switching control device for selecting and instructing any one of the outputs of the plurality of current sensors based on detection information of the rotational speed of the engine of the vehicle, and at least the engine as the plurality of current sensors A first current sensor for measuring the charge / discharge current of the battery at the start of the vehicle, a second current sensor for measuring the charge / discharge current of the battery while the vehicle is running, and idling of the vehicle being stopped a third current sensor for measuring the discharge current of the battery is provided in the sensor switching controller, The first current sensor is selected when the ignition is turned “ON” and when a signal to restart the engine is received, and the third current sensor is turned on when the engine speed becomes “0”. When selected, the second current sensor is selected when the engine speed becomes equal to or higher than the set speed .
[0008]
That is, focusing on the fact that the battery charge / discharge current fluctuates as the digit changes, it is closely related to the engine speed of the vehicle. By selecting one of the outputs of multiple current sensors with different scale current values and acquiring the charge / discharge current value of the battery, the signal of the current sensor with the smallest full scale current value can be selected according to the situation. Thus, accurate measurement can be performed in real time.
Moreover, the rotational speed of the vehicle engine is often output as detection information for output to a so-called tachometer or the like, and it is possible to further reduce the cost by using existing equipment. It becomes.
[0009]
Further, the relation between the engine speed of the vehicle and the charge / discharge current of the battery is roughly classified, and the charge / discharge current of the battery before starting the engine, that is, when the engine speed is “0” (in this case, the discharge current) Only) is the smallest, and the charge / discharge current (mainly discharge current) of the battery when the engine starts, that is, when the engine speed rises from “0” is maximized, and during normal driving, that is, the engine speed is within a certain range. The charge / discharge current of the battery when it fluctuates in the middle is in the middle.
As described above, at least the first to third current sensors are provided, and by switching which sensor output is selected based on the detection information of the engine speed, it is possible to accurately change the charge / discharge current of the battery. Correspondingly, the charge / discharge current of the battery can be accurately measured.
[0010]
Further, by providing the above-described structure according to claim 2, wherein the sensor switching device, based on the state duration information in state or set range rotational speed becomes the set value and the same value of the engine, the It is configured to select and instruct one of the outputs of the plurality of current sensors when a set time elapses while the engine speed is equal to the set value or within the set range . .
That is, the duration information of the state where the engine speed is the same as the set value or in the set range is also used for selecting the outputs of the plurality of current sensors, for example, when the engine starts. After waiting for a large discharge current to settle down, it becomes possible to make fine selections such as switching to a state where the output of a current sensor with a smaller full-scale current value is selected. It can correspond to.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a vehicle equipped with a battery charge / discharge current measuring device of the present invention will be described below with reference to the drawings.
As schematically shown in FIG. 2, in the present embodiment, an automobile 1 is exemplified as a vehicle, and the automobile 1 is provided with a battery charge / discharge current measuring device that measures the charge / discharge current of the battery BT.
The battery BT supplies electric power for starting the engine 2 of the automobile 1 and operating power of various electrical components such as a car stereo equipped in the automobile 1 and is charged by electricity generated by the power of the engine 2.
[0012]
The battery charge / discharge current measuring device CM for measuring the charge / discharge current of the battery BT has three current sensors, a first current sensor 11, a second current sensor 12, and a third current sensor 13, as shown in FIG. CS and the controller CO which selects the output of any one of the 1st-3rd current sensors 11, 12, and 13 and outputs as a charge / discharge current measurement value of the battery BT are comprised.
In the present embodiment, the first to third current sensors 11, 12, and 13 are attached to the wiring connected to the battery BT, and have a type in which a magnetic field generated by a current flowing through the wiring is detected by a Hall element. I use it.
[0013]
The first current sensor 11 has a full-scale current value of 500 A, and detects the charge / discharge current of the battery BT when the engine 2 is started. The second current sensor 12 has a full-scale current value of 50 A. The third current sensor 13 has a full-scale current value of 5 A and the charging / discharging current of the battery BT while the idling of the automobile 1 is stopped. It is for detecting. By selecting one of the outputs of the first to third current sensors 11, 12, and 13, the relationship is equivalent to switching the measurement range of the ammeter, and the measurement range is switched as described later. Therefore, it is possible to obtain a good measurement resolution corresponding to the use state of the battery BT in real time.
[0014]
The controller CO is instructed to select any one of the outputs of the first to third current sensors 11, 12, and 13 based on the detection information of the engine speed detector 14 provided in the automobile 1. A sensor switching control device 15 and a data measurement control device 16 that outputs the output of the current sensor CS instructed by the sensor switching control device 15 to the battery monitoring device 3 and the vehicle side control device 4 are provided. The engine speed detector 14 detects the rotational speed of the shaft of the engine 2 or uses what is output to the tachometer by detecting the spark of the igniter.
[0015]
Next, the operation of the sensor switching control device 15 will be described based on the flowchart of FIG. 3 executed by the sensor switching control device 15.
The sensor switching control device 15 instructs the data measurement control device 16 to select the output of the first current sensor 11 as an initial value at the same time that the ignition of the automobile 1 is “ON”, and then performs the processing of FIG. Execute repeatedly at high speed.
Further, the automobile 1 exemplified in the present embodiment is of a type having a so-called idling stop function, and the sensor switching control device 15 is provided on the automobile side when the automobile 1 is in an idling stop state due to a signal waiting or the like. When receiving a signal from the control device 4 that cancels the idling stop and restarts the engine 2, the data measurement control device 16 is instructed to select the output of the first current sensor 11 as an interrupt process. Further, when the cell starter is activated by operating the ignition key, the data measurement control device 16 is instructed to select the output of the first current sensor 11 as an interrupt process.
[0016]
The sensor switching control device 15 includes a first information source for selecting and instructing any one of the outputs of the first to second current sensors 11, 12, and 13 in addition to the engine speed detector 14. Two timers, a timer and a second timer, are provided. The first timer measures the elapsed time after the engine speed reaches “0” rotation, and the first current sensor 11 or the second current sensor 12. The second timer is used to detect the timing of transition from the state in which the output of the third current sensor 13 is instructed to the state in which the output of the third current sensor 13 is instructed to select. Rotation) The timing at which the elapsed time from the above is counted and the transition from the state of selecting and instructing the output of the first current sensor 11 to the state of selecting and instructing the output of the second current sensor 12 It is used as to detect.
The sensor switching control device 15 uses the first timer and the second timer to set the rotation speed of the engine 2 to a set value (for example, “0” rotation) or a setting range (for example, “200” rotation). The duration information of the state in the above is acquired, and based on the duration information, any one of the outputs of the three current sensors CS is selected and instructed.
[0017]
Hereinafter, the processing of FIG. 3 will be described in order.
First, the rotational speed of the engine 2 is read, and if the rotational speed is "0" (step # 1), the stop of the second timer is confirmed, and if the second timer is operating, it is stopped ( Step # 2), it is necessary to start the first timer on condition that “the first timer has not started to measure” and “not in the state of selecting and instructing the output of the third current sensor 13” (Step # 3). When the above two conditions are met, that is, when it is detected for the first time that the engine speed is “0” rotation and the processing route after step # 2 is entered, the first timer is started (step # 4). ). In other cases, after the set time (for example, 10 seconds) elapses (step # 5) after the time measured by the first timer elapses, an instruction to the data measurement control device 16 is sent to the first time. The state of selecting and instructing the output of the first current sensor 11 or the second current sensor 12 is switched to the state of selecting and instructing the output of the third current sensor (step # 6). At this time, the first timer is also reset to stop timing.
By the processing of step # 3 to step # 6, when the automobile 1 is idling stopped due to signal stoppage or the like, the state in which the output of the second current sensor 12 is instructed to the state in which the output of the third current sensor is instructed to be selected. By switching, the first current sensor 11 having a small full-scale current value can measure current with high resolution.
[0018]
On the other hand, if the engine 2 has already started and the engine speed is equal to or higher than the set speed (for example, “200” rotation) (step # 7), confirm that the first timer has stopped, If the timer is in operation, stop it (step # 8), and "condition that the second timer has not started to measure" and "not ready to select the output of the second current sensor 13" It is determined whether or not it is necessary to start the second timer (step # 9). When the above two conditions are met, that is, when it is first detected that the engine speed is equal to or higher than the set speed and the processing route after step # 8 is entered, the second timer is started (step #). 10). In other cases, wait for the set time (for example, 30 seconds) of the time measured by the second timer (step # 11), and when the set time elapses, the instruction to the data measurement control device 16 is The state of selecting and instructing the output of the first current sensor 11 is switched to the state of selecting and instructing the output of the second current sensor (step # 12). At this time, the second timer is also reset to stop timing.
By the process of step # 9 to step # 12, when the automobile 1 starts the engine 2 and the discharge current from the battery BT has settled to some extent, the second current state is selected from the state in which the output of the first current sensor 12 is selected. By switching to a state in which the output of the current sensor is selected and instructed, the second current sensor 12 having a small full-scale current value can measure current with high resolution.
[0019]
The data measurement control device 16 instructed by the current sensor CS to be selected as described above outputs the output of the instructed current sensor CS to the battery monitoring device 3 and the vehicle side control device 4 and is built in. The measured value is stored in the memory and the integrated value of the charge / discharge current of the battery BT is obtained.
The data measurement control device 16 samples the output of the current sensor CS instructed at a constant cycle. This sampling cycle is a short sampling cycle when the engine 2 is started. Is set so as to have a long sampling period during driving.
[0020]
[Another embodiment]
Hereinafter, other embodiments of the present invention will be listed.
(1) In the above embodiments, the current sensor CS for measuring the charge and discharge current of the battery BT, but illustrates a case with three current sensors CS of the first to third current sensors 11, 12, 13 Four or more current sensors CS may be provided.
For example, in the above embodiment, when the rotation speed of the engine 2 is “0” rotation, the output of the third current sensor 13 having the smallest full-scale current value is selected and instructed. The number of "0" rotation is divided into a state before starting the engine immediately after turning the ignition "ON" and a state where the engine is stopped at idling stop. May be provided with a current sensor CS.
When idling is stopped, there is a high possibility that the car stereo or other electrical equipment installed in the car 1 is being used, and the charge / discharge current of the battery BT is more than that used immediately after the ignition is turned “ON”. Therefore, as described above, finer measurement resolution can be achieved by distinguishing between the state immediately before the engine is started immediately after the ignition is turned "ON" and the state in which the engine is stopped at idling stop. Can be managed.
[0021]
(2) In the above embodiment, the case where the detection information of the engine speed detector 14 originally provided in the automobile 1 is used as the detection information of the engine speed of the engine 2 is exemplified. Separately from the engine speed detector 14, a device for detecting the speed of the engine 2 may be provided exclusively for the battery charge / discharge current measuring device CM.
(3) In the above embodiment, the current sensor CS is exemplified by a form in which the magnetic field formed by the charge / discharge current is detected by the Hall element. However, the present invention is applied to measurement by various other types of current sensors. Applicable.
(4) In the above embodiment, in order to acquire the duration information of the state where the rotational speed of the engine 2 is the same as the set value or in the set range, the first timer and the second timer are used. Although a timer is provided, these may be configured by a single timer.
[0022]
【The invention's effect】
According to the first aspect of the present invention, it is noted that the situation in which the charging / discharging current of the battery fluctuates greatly as the digit is different is closely related to the rotational speed of the engine of the vehicle. By selecting one of the outputs of multiple current sensors with different full-scale current values based on the detection information of the number and obtaining the charge / discharge current value of the battery, the full-scale current value is as much as possible according to the situation By selecting a signal from a current sensor having a small value, accurate measurement can be performed in real time.
Moreover, the rotational speed of the vehicle engine is often output as detection information for output to a so-called tachometer or the like, and it is possible to further reduce the cost by using existing equipment. It becomes.
[0023]
In addition, at least first to third current sensors are provided, and it is possible to accurately respond to changes in the charge / discharge current of the battery by switching which sensor output is selected based on detection information of the engine speed. Thus, the charge / discharge current of the battery can be accurately measured.
Further, according to the configuration of the second aspect , the output of the plurality of current sensors can be selected together with the duration information of the state where the engine speed is equal to the set value or the set range. By using it, for example, waiting for the large discharge current flowing when the engine starts to settle down, then switching to a state where the output of the current sensor with a smaller full scale current value is selected, etc., it becomes possible to make fine selection, It is possible to cope with changes in the charging / discharging current of the battery even more accurately.
[Brief description of the drawings]
FIG. 1 is a block configuration diagram of a battery charge / discharge current measuring apparatus according to an embodiment of the present invention. FIG. 2 is a layout diagram of a battery and the like in an automobile according to the embodiment of the present invention. Flow chart according to form [Explanation of symbols]
BT Battery CM Battery charge / discharge current measuring device CS Current sensor 11 First current sensor 12 Second current sensor 13 Third current sensor 15 Sensor switching control device

Claims (2)

A vehicle equipped with a battery charge / discharge current measuring device for measuring a charge / discharge current of a battery with a current sensor,
With multiple current sensors with different full-scale current values,
A sensor switching control device for selecting and instructing any one of the outputs of the plurality of current sensors based on detection information of the rotational speed of the engine of the vehicle;
As the plurality of current sensors, at least a first current sensor for measuring the charge / discharge current of the battery at the time of starting the engine, and a first current sensor for measuring the charge / discharge current of the battery during travel of the vehicle. A second current sensor, and a third current sensor for measuring a charge / discharge current of the battery during idling stop of the vehicle ,
The sensor switching control device selects the first current sensor when the ignition is turned "ON" and when a signal indicating that the engine is restarted is received, and when the engine speed becomes "0". And a battery charge / discharge current measuring device configured to select the second current sensor when the third current sensor is selected and the engine speed is equal to or higher than a set speed . In the sensor switching control device, the engine speed is equal to the set value based on duration information in a state where the engine speed is equal to a set value or in a set range . 2. The battery charge / discharge current measuring device according to claim 1, wherein the battery charge / discharge current measuring device is configured to select and instruct one of outputs of the plurality of current sensors when a set time elapses in a state or a set range. Vehicle.

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