JP2012232613A - Lamp state detection device and lamp state detection method - Google Patents

Abstract

Provided are a lamp state detection device and a lamp state detection method capable of sufficiently increasing a return determination value and preventing erroneous detection of disconnection return.
A microcomputer detects a disconnection of a main lamp when a current value detected at a disconnection detection timing t1 in a normal time is less than a determination value Ith1, and a current value detected at a return detection timing t2 when the disconnection is detected. Is detected to be a return determination value Ith2 or more, the main lamp disconnection recovery is detected. The determination value Ith1 is set to a value smaller than the drive current Iγ that is the sum of the drive currents flowing through the two main lamps and greater than the drive current Iβ that is the sum of the drive currents flowing through one main lamp and the sub lamp. Is done. The return determination value Ith2 is set to a value that is larger than the drive current Iγ that is the sum of the drive currents flowing through the two main lamps and smaller than the drive current Iα that is the sum of the drive currents that flow through the two main lamps and the sub lamps. ing.
[Selection] Figure 4

Description

  The present invention relates to a lamp state detection device and a lamp state detection method, and more particularly to a lamp state detection device and a lamp state detection method for detecting the states of a plurality of main lamps arranged in front of or behind a vehicle.

  Conventionally, a vehicle (automobile) is provided with a plurality of left and right turn signal lamps. These turn signal lamps are usually formed of so-called light bulbs (incandescent bulbs, halogen bulbs, etc.), and when the direction indicator lever is rotated to the left, a drive current is intermittently supplied to the left lamps. When the lamps flash simultaneously and the direction indicator lever is rotated to the right, drive current is intermittently supplied to the right lamps, and the right lamps flash simultaneously.

  By the way, in each of the turn signal lamps, disconnection (ball breakage) occurs due to deterioration with time or the like. In view of this, there has been proposed a lamp state detection device that detects a disconnection when the drive current supplied to each turn signal lamp decreases and detects a disconnection by increasing the blinking cycle of the lamp when the disconnection is detected (for example, a patent). Reference 1).

  The detailed operation of the lamp state detection device disclosed in Patent Document 1 will be described with reference to FIG. In the figure, a solid line α indicates a normal current change in which, for example, three turn signal lamps (= three main lamps) are not disconnected, and a solid line β indicates that any one of the three turn signal lamps is disconnected. When the current changes. In FIG. 5, T1 is a normal lighting period, and T2 (<T1) is a disconnection lighting period.

  As shown in the figure, the lamp state detection device is configured such that the sum of the drive currents flowing through the three turn signal lamps detected at the disconnection detection timing t1 set near the end of the lighting period T1 at the normal time is equal to or less than the determination value Ith1. The disconnection of the turn signal lamp is detected and the lighting period is switched from T1 to T2. Thereafter, the lamp state detection device disconnects the turn signal lamp when the sum of the drive currents flowing through the three turn signal lamps detected at the return detection timing t2 set near the end of the lighting period T2 is equal to or higher than the return determination value Ith2. A return is detected and the lighting period is switched from T2 to T1.

  The determination value Ith1 is sufficiently smaller than the current value Iα (t1) at the disconnection detection timing t1 of the drive current that decreases along the solid line α in FIG. 5 and the drive current that decreases along the solid line β in FIG. It is set to a value sufficiently larger than the current value Iβ (t1) at the disconnection detection timing t1 (Iβ (t1) <Ith1 <Iα (t1)).

  The return determination value Ith2 is sufficiently larger than the current value Iβ (t2) at the return detection timing t2 of the drive current that decreases along the solid line β in FIG. 5, and the drive current that decreases along the solid line α in FIG. It is set to a value sufficiently smaller than the current value Iα (t2) at the return detection timing t2 (Iβ (t2) <Ith2 <Iα (t2)).

  The turn signal lamp has a large current variation as in a general light bulb, and the closer to the start of lighting, the greater the influence of the variation due to the influence of the rush current. According to the lamp state detection device, by setting the disconnection detection timing t1 and the return detection timing t2 near the end of the lighting periods T1 and T2, the influence of current variation can be sufficiently suppressed, and an error in disconnection and disconnection return can be suppressed. Detection is prevented.

  By the way, the lamp state detection device detects the drive current a predetermined number of times at the disconnection detection timing t1 and the return detection timing t2, and compares the average value with the determination value Ith1 and the return determination value Ith2. For this reason, if the disconnection detection timing t1 and the return detection timing t2 are set near the end of the lighting periods T1 and T2 as described above, the lighting ends before the drive current can be detected a predetermined number of times. Then, it is necessary to detect the rest in the next lighting period, and there is a problem that the timing for detecting disconnection or return is delayed.

  In order to prevent this timing delay, it is necessary to set the return detection timing t2 not to the end of lighting, but to a time with a large variation immediately after the lighting starts and the rush current settles. However, the conventional return determination value is set between the drive current when the three turn signal lamps are normally lit and the drive current when one of the three turn signal lamps is disconnected. The return judgment value cannot be set sufficiently large. In particular, since a rush current higher than usual flows when the turn signal lamp starts to blink, the return detection timing t2 is set to a time with a large variation immediately after the start of lighting and the rush current settles as described above. In spite of the disconnection, there is a problem that the return determination value may be exceeded and erroneous detection may occur.

JP 2007-246017 A

  Therefore, an object of the present invention is to provide a lamp state detection device and a lamp state detection method that can sufficiently increase the return determination value and prevent erroneous detection of disconnection return.

  The invention according to claim 1 for solving the above-described problem includes a plurality of main lamps arranged in front or rear of a vehicle, one sub lamp having a smaller drive current than the main lamp, the main lamp, Lamp driving means for intermittently supplying driving current to the sub lamps to simultaneously flash these lamps, and state detecting means for detecting the states of the plurality of main lamps during flashing by the lamp driving means The lamp state detection apparatus further includes a current detection unit that detects a total of drive currents flowing through the plurality of main lamps and the sub lamps, and the state detection unit is configured to perform a predetermined operation from the start of lighting of the main lamps and the sub lamps in a normal state. The current value detected by the current detection means is determined at the disconnection detection timing set after the elapse of time. When the disconnection is detected, the disconnection of the main lamp is detected, and when the disconnection is detected, the current value detected by the current detection means at the return detection timing set after a predetermined time has elapsed from the start of lighting of the main lamp and the sub lamp. A disconnection return of the main lamp is detected when the return determination value is equal to or greater than a return determination value, and the determination value is smaller than a total of drive currents flowing through the plurality of main lamps, and a remaining amount excluding one of the plurality of main lamps Set to a value larger than the sum of drive currents flowing through the main lamp and the sub lamp, the return determination value is greater than the sum of drive currents flowing through the plurality of main lamps, and the plurality of main lamps and the A lamp state detection device characterized by being set to a value smaller than the sum of drive currents flowing through the sub-lamps.

  According to a second aspect of the present invention, drive current is intermittently supplied to a plurality of main lamps arranged in front or rear of a vehicle and one sub lamp having a drive current smaller than that of the main lamp. In a lamp state detection method for simultaneously flashing lamps and detecting a state of the plurality of main lamps during flashing, a total of drive currents flowing through the plurality of main lamps and the sub lamps is detected. The disconnection of the main lamp is detected when the total of the drive currents detected at the disconnection detection timing set after the elapse of a predetermined time from the start of lighting of the sub lamp is less than a determination value, and the main lamp and the The drive current detected at the return detection timing set after elapse of a predetermined time from the start of lighting of the sub lamp When the total is equal to or greater than the return determination value, the disconnection return of the main lamp is detected, the determination value is smaller than the total drive current flowing through the plurality of main lamps, and one of the plurality of main lamps is excluded. Set to a value greater than the sum of the drive currents flowing through the remaining main lamps and the sub lamps, the return determination value is greater than the sum of drive currents flowing through the plurality of main lamps, and the plurality of main lamps The lamp state detection method is characterized in that it is set to a value smaller than the total of drive currents flowing through the sub lamps.

  As described above, according to the first and second aspects of the invention, the return determination value is larger than the sum of the drive currents flowing through the plurality of main lamps, and is greater than the sum of the drive currents flowing through the plurality of main lamps and sub-lamps. Is set to a small value, the return determination value can be set to a sufficiently large value, and erroneous detection of disconnection return can be prevented.

It is a block diagram which shows one Embodiment of the lamp state detection apparatus of this invention. It is the schematic of the vehicle which attached the main lamp and sub lamp | ramp shown in FIG. It is a time chart of the electric current supplied to a right lamp group. It is a flowchart which shows the disconnection detection processing procedure of the microcomputer shown in FIG. It is a time chart of the sum total of the drive current which flows into three turn signal lamps for demonstrating operation | movement of the conventional lamp state detection apparatus.

  Hereinafter, a lamp state detection apparatus that implements the lamp state detection method of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram showing an embodiment of a lamp state detection device of the present invention. FIG. 2 is a schematic view of a vehicle equipped with the main lamp and the sub lamp shown in FIG. As shown in the figure, the lamp state detection device 1 includes a right lamp group 2 arranged on the right side of the vehicle, a left lamp group 3 arranged on the left side of the vehicle, a battery voltage + B, a right lamp group 2, and a left lamp group. A high-side switch 4 provided between the lamp group 3, a microcomputer (hereinafter abbreviated as “microcomputer”) 5 for controlling on / off of the high-side switch 4, and a power supply unit 6 are provided.

  As shown in FIG. 2, the right lamp group 2 includes, for example, two main lamps 2a and 2b of 21 watts arranged at the right front and right rear of the vehicle, and 5 watts arranged at the right side of the vehicle. And one sub lamp 2c. The main lamps 2 a and 2 b and the sub lamp 2 c are connected in parallel to each other, one end is connected to the ground, and the other end is connected to the battery power source + B via the high side switch 4. As is clear from the wattage, the sub lamp 2c has a smaller drive current than the two main lamps 2a and 2b.

  As shown in FIG. 2, the left lamp group 3 includes, for example, two main lamps 3a and 3b of 21 watts disposed on the left front and left rear of the vehicle, and 5 watts disposed on the left side of the vehicle. And a single sub lamp 3c. The main lamps 3 a and 3 b and the sub lamp 3 c are connected in parallel to each other, one end is connected to the ground, and the other end is connected to the battery power source + B via the high side switch 4. As is clear from the wattage, the sub lamp 3c has a smaller drive current than the two main lamps 3a and 3b.

  The high side switch 4 includes a right high side switch provided between the battery power source + B and the right lamp group 2 and a left high side switch provided between the battery terminal + B and the left lamp group 3 (both are (Not shown). The high-side switch 4 is composed of a semiconductor switch such as a power MOSFET, for example, and its gate is connected to the microcomputer 5 via an interface (hereinafter referred to as I / F) 7.

  The high-side switch 4 is provided with a sense terminal that outputs a current value 1 / n of the current flowing through the high-side switch 4, and the sense terminal is connected to the microcomputer 5 via the I / F 7. That is, the sum of the drive currents flowing through the two main lamps 2a, 2b and sub lamp 2c constituting the right lamp group 2 is output from the sense terminal of the right high side switch. From the sense terminal of the left high side switch, the sum of the drive currents flowing through the two main lamps 3a, 3b and sub lamp 3c constituting the left lamp group 3 is output. As is clear from the above, the high side switch 4 corresponds to the current detection means.

The microcomputer 5 is connected to a turn switch SW1 and a hazard switch SW2 via an I / F 8. When the direction indicator lever is contact of the turn switch SW1 is rotated to the right is connected to the right terminal T _R, the microcomputer 5, intermittently for the right lamp unit 2 by intermittently turning on and off the right high-side switch A drive current is supplied to the right lamp group 2 so that the right lamp group 2 blinks simultaneously.

When the direction indicating lever is rotated to the left and the contact point of the turn switch SW1 is connected to the left terminal _TL , the microcomputer 5 intermittently controls the left high side switch on and off to intermittently control the left lamp group 3. A drive current is supplied to the left lamp group 3 so that the left lamp group 3 blinks simultaneously. When the hazard switch SW is turned on, the microcomputer 5 intermittently controls the right and left high-side switches connected to the right lamp group 2 and the left lamp group 3 to both the right lamp group 2 and the left lamp group 3. On the other hand, the drive current is intermittently supplied, and the right lamp group 2 and the left lamp group 3 are blinked simultaneously. As is clear from the above, the microcomputer 5 functions as lamp driving means.

  Further, the microcomputer 5 described above functions as a state detection means, and has an A / D converter built therein, and can capture the current value input from the sense terminal of the high side switch 4 by A / D conversion. The microcomputer 5 detects the state of the main lamps 2a, 2b, 3a, and 3b based on the acquired current value.

  Next, the operation of the lamp state detection apparatus 1 having the above-described configuration will be described with reference to FIGS. FIG. 3 is a flowchart showing a disconnection detection processing procedure of the microcomputer shown in FIG. FIG. 4 is a time chart of the current supplied to the right lamp group. In FIG. 4, a solid line α indicates a drive current that flows through the right lamp group 2 when none of the two main lamps 2a, 2b and one sub lamp 2c are disconnected. A solid line β indicates a drive current flowing in the right lamp group 2 when only one of the two main lamps 2a and 2b is disconnected and one sub lamp 2c is not disconnected. A solid line γ indicates a drive current flowing through the right lamp group 2 when the two main lamps 2a and 2b are not disconnected and only one sub lamp 2c is disconnected. Here, in order to simplify the description, detection of disconnection and return of disconnection of the right lamp group 2 will be described, and description of the left lamp group 3 will be omitted because it is the same.

The microcomputer 5 starts the operation in response to the ignition on of the vehicle. First, the microcomputer 5, or contact of the turn switch SW1 is connected to the right terminal T _R, waiting for the hazard switch SW2 is turned on (at step S1 Y) advances to the next step S2. In step S2, the microcomputer 5 determines whether or not a disconnection has already been detected and the disconnection flag is on.

  If the disconnection flag is off (N in step S2), the microcomputer 5 turns on and off the right high-side switch in a normal cycle and blinks the right lamp group 2 in a normal cycle (step S3). Thereafter, as shown in FIG. 4, when the microcomputer 5 reaches the disconnection detection timing t <b> 1 set after a predetermined time has elapsed from the start of lighting of the right lamp group 2 (Y in Step S <b> 4), the microcomputer 5 detects from the sense terminal of the right high-side switch. The output is intermittently captured a predetermined number of times, and the average value is detected as the current value flowing through the right lamp group 2 (step S5).

  Next, the microcomputer 5 compares the detected current value with the determination value Ith1, and when the detected current value is less than the determination value Ith1 (Y in step S6), detects the disconnection and turns on the disconnection flag. At the same time, after the blinking cycle of the right lamp group 2 is changed from the normal cycle to a high flasher (hereinafter referred to as “high flasher”) cycle that is earlier than the normal cycle (step S7), the process proceeds to step S8. On the other hand, when the detected current value is greater than or equal to the determination value Ith1 (N in step S6), the microcomputer 5 determines that it is normal and proceeds to step S8 immediately without proceeding to step S7.

  In step S8, when the turn switch SW1 and the hazard switch SW2 are turned off (Y in step S8), the microcomputer 5 turns off the right high-side switch and turns off the right lamp group 2 (step S9). Return to S1. On the other hand, if the turn switch SW1 and the hazard switch SW2 are not turned off (N in step S8), the microcomputer 5 immediately returns to step S2.

  On the other hand, if the disconnection flag is on (Y in step S2), the microcomputer 5 turns on and off the right high-side switch in the high-fla cycle, and blinks the right lamp group 2 in the high-fla cycle (step S10). After that, as shown in FIG. 4, when the microcomputer 5 comes to the return detection timing t2 (= t1) set after a lapse of a predetermined time from the start of blinking of the right lamp group 2 (Y in step S11), the microcomputer 5 The output from the sense terminal is intermittently taken a predetermined number of times, and the average value is detected as the current value flowing through the right lamp group 2 (step S12).

  Next, the microcomputer 5 compares the detected current value with the return determination value Ith2, and when the detected current value is greater than or equal to the return determination value Ith2 (Y in step S13), the disconnection return (returned to normal) ) Is detected and the disconnection flag is turned off, and the blinking cycle of the right lamp group 2 is changed from the high-flare cycle to the normal cycle (step S14), and then the process proceeds to step S8. On the other hand, when the detected current value is less than the return determination value Ith2 (N in step S13), the microcomputer 5 proceeds to step S8 immediately without proceeding to step S14, assuming that the disconnection remains.

  Next, setting of the determination value Ith1 and the return determination value Ith2 described above will be described with reference to FIG. As shown in FIG. 4, the current flowing through the right lamp group 2 is almost constant when a large rush current flows at the start of lighting and the rush current decreases and becomes a steady drive current. Then, the determination value Ith1 flows to the steady drive current Iγ (= two main lamps 2a, 2b) that flows to the right lamp group 2 when only the sub lamp 2c of the lamps 2a to 2c constituting the right lamp group 2 is disconnected. The steady drive that is sufficiently smaller than the sum of the steady drive currents and flows to the right lamp group 2 when only one of the two main lamps 2a, 2b of the lamps 2a-2c constituting the right lamp group 2 is disconnected. The current Iβ is set to a value sufficiently larger than the current Iβ (= the sum of the steady driving currents flowing through the other one of the two main lamps 2a and 2b and the sub lamp 2c) (that is, Iβ <Ith1 <Iγ).

The return determination value Ith2 is a steady driving current Iα (= two main lamps 2a, 2b and a sub lamp) that flows in the right lamp group 2 when no disconnection occurs in any of the lamps 2a to 2c constituting the right lamp group 2. 2c) and sufficiently larger than the steady drive current Iγ (ie, Iγ <Ith2 <Iα). The steady driving currents Iα, Iβ, and Iγ described above vary due to, for example, lamp characteristics, electronic components, reading errors of the microcomputer 5, and the like, but this variation range can be predicted from the lamp characteristics, electronic components, microcomputer 5, and the like. Therefore, the MAX (maximum) value and the MIN (minimum) value of each of the steady drive currents Iα, Iβ, and Iγ are obtained. Actually, the determination value Ith1 and the return determination value are within the ranges shown in the following formulas (1) and (2). Set Ith2.
MAX value of Iβ <I1 <MIN value of Iγ (1)
MIN value of Iγ <I2 <MIN value of Iα (2)

  As a result, when one of the main lamps 2a and 2b is disconnected, the current flowing through the right lamp group 2 has a waveform indicated by a solid line β. Therefore, the disconnection can be detected at a disconnection detection timing t1 which is less than the determination value Ith1. In addition, if all the lamps 2a to 2c are inspected after the disconnection is detected and all the lamps 2a to 2c are in a normal state, the current flowing through the right lamp group 2 has the waveform shown by the solid line α. At t2, the return determination value Ith2 is exceeded, and disconnection can be detected. That is, in the past, both the determination value Ith1 and the return determination value Ith2 were within the range of the drive current Iβ to the drive current Iγ (that is, Iβ <Ith1, Ith2 <Iγ), but the return determination value Ith2 as in the present embodiment. Is set to a value larger than the steady drive current Iγ and smaller than the steady drive current α, the return determination value Ith2 can be set to a large value, and erroneous detection of disconnection return can be prevented.

  In addition, according to embodiment mentioned above, although two main lamps were demonstrated to the example, this invention is not limited to this. The number of main lamps may be two or more, and may be three or four.

  Further, according to the above-described embodiment, the disconnection detection timing t1 and the return detection timing t2 are set to the same timing, but the present invention is not limited to this. The return detection timing t2 may be set after the disconnection detection timing t1.

  Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

2a main lamp 2b main lamp 2c sub lamp 3a main lamp 3b main lamp 3c sub lamp 4 high side switch (current detection means)
5 Microcomputer (lamp drive means, state detection means)

Claims (2)

A plurality of main lamps arranged at the front or rear of the vehicle, one sub lamp having a driving current smaller than that of the main lamp, and intermittently supplying driving current to the main lamp and the sub lamp. In a lamp state detecting device comprising: lamp driving means for simultaneously flashing; and state detecting means for detecting states of the plurality of main lamps during flashing by the lamp driving means.
Current detection means for detecting a total of drive currents flowing through the plurality of main lamps and the sub lamps;
The main lamp when the current detection means detects that the current value detected by the current detection means is less than a determination value at a disconnection detection timing set after a lapse of a predetermined time from the start of lighting of the main lamp and the sub lamp at normal times. When the disconnection is detected and the current value detected by the current detection means is greater than or equal to the return determination value at the return detection timing set after the elapse of a predetermined time from the start of lighting of the main lamp and the sub lamp. Detects the main lamp disconnection recovery,
The determination value is smaller than the sum of the drive currents flowing through the plurality of main lamps and greater than the sum of the drive currents flowing through the remaining main lamps and the sub lamps excluding one of the plurality of main lamps. Set to
The return determination value is set to a value that is larger than a total of drive currents flowing through the plurality of main lamps and smaller than a total of drive currents flowing through the plurality of main lamps and the sub lamps. Lamp state detection device. The drive current is intermittently supplied to a plurality of main lamps arranged in front or rear of the vehicle and one sub lamp having a drive current smaller than that of the main lamps so that these lamps flash simultaneously. In the lamp state detecting method for detecting the state of the plurality of main lamps,
Detecting a total of drive currents flowing through the plurality of main lamps and the sub lamps;
When the sum of the drive currents detected at the disconnection detection timing set after the elapse of a predetermined time from the start of lighting of the main lamp and the sub lamp at a normal time is less than a determination value, the disconnection of the main lamp is detected and the disconnection is detected. When the sum of the drive currents detected at the return detection timing set after the elapse of a predetermined time from the start of lighting of the main lamp and the sub lamp at the time is greater than or equal to a return determination value, the disconnection return of the main lamp is detected.
The determination value is smaller than the sum of the drive currents flowing through the plurality of main lamps and larger than the sum of the drive currents flowing through the remaining main lamps and the sub lamps except for one of the plurality of main lamps. Set,
The return determination value is set to a value that is larger than a total of drive currents flowing through the plurality of main lamps and smaller than a total of drive currents flowing through the plurality of main lamps and the sub lamps. Lamp status detection method.

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