JP3589049B2 - Ignition key detection processing method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for detecting an ignition key being turned off by a controller of a traveling motor of an electric vehicle or the like.
[0002]
[Prior art]
In recent years, electric vehicles without exhaust gas have attracted attention in terms of global environmental protection, and by turning on the ignition key, the driving motor equivalent to a conventional engine is started by its controller, and the ignition key is turned off to ensure safety. Need to stop the vehicle.
[0003]
As a conventional example of determining whether the ignition key is on or off, when inputting the ignition key on / off signal to the microcomputer and making it determined by software, the previous input state is monitored at a certain cycle and the state of off for a certain time It was determined that the ignition key was turned off if continued.
[0004]
[Problems to be solved by the invention]
However, the conventional method of monitoring input at a fixed cycle uses a timer interrupt to create a fixed cycle, and if the timer interrupt stops operating for some reason, it is detected that the ignition key is turned off. There is a problem that the key cannot be turned off mechanically and electrically turned on.
[0005]
In addition, even if the ignition key is turned off, the inverter is driven by the microcomputer until the traveling motor drops to the predetermined speed, and if any abnormality occurs at that time, the traveling motor must be in a low speed state close to stop. For example, there is a problem that the inverter is in a driving state and gives a sense of strangeness to the driver.
[0006]
An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a highly safe electric vehicle drive controller capable of reliably detecting an ignition key-off and stopping a motor drive.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention detects whether an ignition key is on or off during a main process that does not depend on an interrupt or the like, and a ratio of off is constant at an on / off ratio detected within a certain period of time. When the value is equal to or larger than the value, it is determined that the ignition key is turned off.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
In order to solve the above-mentioned problem, the present invention detects whether an ignition key is on or off during a main process that does not depend on an interrupt or the like, and a ratio of off is constant at an on / off ratio detected within a certain period of time. This is an ignition key detection processing method for determining that the ignition key is turned off when the value is not less than the value.
[0009]
The ignition key detecting method according to claim 1, wherein when the ignition key is determined to be off, the servo is turned off and the power supply from the battery is shut off to stop the inverter driving the motor.
[0010]
In this way, it is possible to reliably detect that the ignition key has been turned off during the main processing without interruption or the like.
[0011]
If the ignition key is detected to be off, the inverter for driving the motor is stopped, so that the servo can be turned off and the power supply from the battery can be cut off.
[0012]
Therefore, it is possible to provide a safe controller for the traveling motor that can surely stop the vehicle.
[0013]
【Example】
An embodiment of the present invention will be described below with reference to the drawings.
[0014]
(Example 1)
In FIG. 1, the main process executes the process in the lowest priority order, so that the ignition detection process is executed at an irregular interval.
[0015]
First, the logic level of the ignition key is input to the microcomputer. Here, it is assumed that the input logic level is associated with the on / off level of the ignition key, and that the ignition key is off when the level is low, and that the ignition key is on when the level is high.
[0016]
The logic level input to the microcomputer, if it is off, the IGOFF (ignition off) counter is incremented, and if it is on, the IGON (ignition on) counter is incremented. In advance, set values for judging ON / OFF are separately set in the above counters, and ON / OFF of the ignition key is determined first at a logic level that matches each set value.
[0017]
At this time, the ratio of the above set values is a condition for judging off, and if it is judged that the ignition key is on, the IGON counter and the IGOFF counter are cleared, and the on / off level is determined at the shortest.
[0018]
Next, the ignition signal, the operation of the IGON counter and the IGOFF counter, and the flow until the level is determined will be described with reference to FIG.
[0019]
In FIG. 2, a is a signal corresponding to the state of the ignition key, which is level-converted to be input to the microcomputer. The ignition key-on is at a high level, the ignition key-off is at a low level, and the horizontal axis represents time change. b is the value of the IGON counter, c is the value of the IGOFF counter, and d is the set value for determining that the ignition key is turned on. e is a set value for determining that the ignition key is turned off, and is set to 10 in this description. The arrow f indicates the timing at which the ignition detection process is executed. This timing has an indefinite interval period, but is shown at a constant period in this description.
[0020]
Next, the case where the ignition is switched from on to off will be described. If the signal level is on or off due to mechanical chattering or noise, if the processing is sequentially performed from time 0 at the detection timing shown by the arrow f, the third time Up to this point, the IGON counter value is updated to 1, 2, and 3 to detect that the ignition is on. At this time, since the ignition is not detected as being off, the IGOFF counter value remains at 0.
[0021]
Further, the ignition-off is detected from the fourth time to the eleventh time, so that the IGOFF counter value is updated from 1 to 8. At this time, since ignition-on is not detected, the IGON counter remains at 3 and is not updated.
[0022]
The IGON counter is updated to 4 to detect the ignition on at the twelfth time, but the IGOFF counter remains at 8 without being updated. Further, since the thirteenth operation is off, only the IGOFF counter is updated, and the fourteenth operation is similarly off, so that the IGOFF counter is updated to 10.
[0023]
In the above description, the counter setting value for IGOFF determination is set to 10. When the counter value matches the counter setting value for IGOFF determination at the 14th time, the ignition key is determined to be off.
[0024]
That is, by setting the value of the IGON / IGOFF determination counter, it is possible to determine whether the ignition key is turned off in the ratio of the on / off level of the ignition key within a certain period of time. In the above example, during the 14 detection timings, the OFF can be determined at a rate of about 71% of the 10 times.
[0025]
In order to improve the responsiveness of the ignition key-off detection, it is more effective to execute it together with the detection in the conventional timer interrupt processing. The detection in the timer interrupt processing will be described with reference to FIG.
[0026]
In the interrupt processing that occurs at regular intervals, first, the level of the ignition key is detected. Then, the value is compared with the previously acquired value, and if the previous value is equal to the current value, the count is incremented. If the value matches the preset value, the currently read level is determined as the level of the ignition key. Is stored as the previous value, and the process ends.
[0027]
That is, the level of the ignition key is detected at regular intervals, and when the read level is continuously set for a set number of times, that is, for a predetermined time, the level of the ignition key is determined at the currently read level.
[0028]
The ignition key detection processing method using the timer interrupt and the detection processing method in the main processing described in the first embodiment are executed in parallel, and the ignition key off level is detected by one of the two detection processing methods. At this time, it is possible to ensure responsiveness by determining that the ignition key is turned off.
[0029]
(Example 2)
FIG. 3 shows a process of stopping the inverter when the ignition key is detected to be off.
[0030]
First, when the ignition key is detected, the current command to the motor is set to zero. Next, a servo-off signal is output to stop the inverter. Further, the power supply from the battery is cut off and necessary termination processing is performed.
[0031]
Although not shown, when the power of the motor is supplied from the battery, the availability of the power is controlled by the inverter. Also, a signal instructing the operation and stop of the inverter is called a servo signal.
[0032]
【The invention's effect】
As is apparent from the above embodiment, according to the first aspect of the present invention, even when the timer interrupt processing is not executed for some reason, it is possible to reliably detect the ignition key being turned off, and to realize the conventional timer interrupt processing. If executed in conjunction with the detection method in the processing, the responsiveness of detection can be further increased.
[0033]
According to the second aspect of the invention, when the ignition key is detected to be off, the inverter is immediately stopped and the power supply from the battery is cut off, so that the motor can be controlled in accordance with the mechanical position of the ignition key. Therefore, it is possible to prevent the driver from feeling uncomfortable.
[0034]
As described above, since the ignition key-off can be reliably detected and the motor drive can be stopped, it is possible to provide a highly safe electric vehicle drive controller.
[Brief description of the drawings]
FIG. 1 is a flowchart illustrating ignition key detection according to a first embodiment of the present invention. FIG. 2 is a conceptual diagram illustrating a flow up to determination of an ignition key level according to a first embodiment of the present invention. FIG. 4 is a flowchart for explaining processing after an ignition key off determination in an example. FIG. 4 is a flowchart for explaining ignition key level determination using a conventional timer interrupt.

Claims (2)

Detects whether the ignition key is on or off by executing the ignition detection process at irregular intervals during the main process that does not depend on interrupts, etc., and the ratio of off is constant at the ratio of on and off detected within a certain time An ignition key detection processing method for determining that the ignition key is turned off when the value is equal to or greater than the value. 2. The ignition key detection processing method according to claim 1, wherein if the ignition key is determined to be off, the servo is turned off and power supply from the battery is shut off to stop the inverter that drives the motor.

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