JP4404716B2 - Variable light distribution type headlamp drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a headlight of variable distribution type capable of suppressing the cost by eliminating necessity for a second CPU through provision of a failure sensing circuit. <P>SOLUTION: A drive device 1 for the headlight is composed of a CPU 2 to compute the rotating amount of a lighting fixture for the headlight from the operating amount of a steering device, a stepping motor drive circuit 7 to rotate the lighting fixture on the basis of the result from computation, a data selector circuit 6, a failure sensing circuit 4 connected with the CPU, and an emergency measure position generating device 5 to emit a first measure position signal in conformity to the signal given by the failure sensing circuit. Thereby the drive device for the headlight of variable distribution type is established, which changes over the data selector circuit to the side with the emergency measure position generating device when a failure is sensed in the CPU and sets the lighting fixture to the emergency measure position, whereby the constitution can be simplified. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention is such that when driving at night, the entire headlamp lamp is rotated in the direction in which the operation is performed in accordance with the operation of the steering device (handle) of the automobile and is irradiated in the traveling direction of the vehicle. The present invention relates to a variable light distribution type headlamp that can improve visibility and improve safety, and more particularly, to a configuration of the driving device thereof.

  As a countermeasure against failure in a conventional apparatus for changing the irradiation axis of a vehicle headlamp, a first calculation means for the vehicle height detection means is prepared to obtain a vehicle height value and to the auxiliary detection means. Prepares a second calculation means, for example, more accurately calculates a change in the attitude of the vehicle depending on the load.

  From the above two calculation results, for example, the optimum illumination angle of the vehicle headlamp that does not cause illusion in an oncoming vehicle or the like is obtained, and the direction of the illumination angle obtained with the drive means as the optimum value for the vehicle headlamp It is aimed at.

  At this time, if it is recognized that an abnormality has occurred on the auxiliary detection means side, it can be set on the oncoming vehicle by setting it to be lower than the direction of the irradiation optical axis when the auxiliary detection means is normal. On the other hand, it is intended not to cause illusion.

Therefore, in the device for changing the irradiation axis of the vehicle headlamp, there is a calculation means for calculating the vehicle height, for example, CPU 1 and a calculation means for calculating the inclination due to the load such as the front elevation of the vehicle body, for example, CPU 2 Since the irradiation direction is set by the driving means with the total value, it is necessary that both of them are always in operation, that is, two CPUs 1 and 2 are required.
JP 2004-168130 A

  In particular, in recent years, as shown in FIG. 3, the AFS system is called, and the CPU 11 calculates the traveling direction of the vehicle according to the operation amount of the steering device such as the steering wheel, and the headlamp 10 a according to the calculation result. And what rotated 10b itself with the stepping motor 13 and turned it to the advancing direction is also employ | adopted.

  Also in this case, the second CPU 14 is provided to constantly monitor the state of the CPU 11. If an abnormality occurs in the CPU 11, the headlamps 10 a and 10 b are moved to the dedicated downward motor. 17 is directed downward so as not to cause illusion in oncoming vehicles and pedestrians. In the figure, reference numeral 15 denotes a drive circuit for the stepping motor 13, and reference numeral 16 denotes a drive circuit for the downward dedicated motor 17.

  However, in the conventional configuration described above, it is necessary for the CPU to constantly monitor the state of the counterpart CPU, that is, since both are required to operate simultaneously, two CPUs are required. Become. Moreover, when an abnormality is found, the control is not so advanced such as increasing the downward angle on the auxiliary detection means side.

  Therefore, when installing a variable light distribution type headlamp, two CPUs must be used in spite of the relatively easy function, resulting in an increase in cost. ing. In addition, the effects and effects obtained by using two CPUs are not so much as to replace the failed CPU and restore the operation simply by setting the lamp downward, but also the effect on the investment cost. It is extremely low, and it has been a problem to solve these points.

As a specific means for solving the above-described conventional problems, the present invention is a variable light distribution type in which a steering device is operated to rotate a headlamp lamp and irradiate a traveling direction of a vehicle. In the headlamp driving device, the driving unit includes a CPU that calculates a rotation amount of the headlamp lamp from an operation amount of the steering device, and a stepping motor that drives the heading based on a calculation result of the CPU. a stepping motor drive circuit for rotating the lighting lamp, an abnormality detection circuit connected to said CPU, a first aid position generator for outputting emergency position signal by the signal from the abnormality detection circuit, the said stepping motor drive circuit a data selector circuit that switches whether to connect the CPU to connect the emergency position generator consists, the abnormality detecting circuit from the periodic or always to the CPU Monitoring the signal, when the signal is a predetermined signal determines that the CPU is operating normally, the data selector circuit connects said CPU to said stepping motor driving circuit, an abnormality in the signal When detected, it is determined that an abnormality has occurred in the CPU, and the data selector circuit switches from a connection between the CPU and the stepping motor drive circuit to a connection between the emergency position generator and the stepping motor drive circuit. Thus, a variable light distribution type headlamp driving device is provided, in which two headlamps are controlled by one CPU by setting the headlamp to the emergency position. Thus, the cost can be reduced and the problem can be solved while maintaining the same function.

  In this type of conventional variable light distribution type headlamp drive device, in the unlikely event that a drive CPU fails, it will always fail so as not to cause illusion in the vehicle in the opposite lane. If it is detected, it is essential to use two CPUs, the second CPU for immediately lowering the irradiation direction of the headlamp, and the variable light distribution type front Although the lighting lamp is expensive, by providing an abnormality detection circuit according to the present invention, the second CPU is unnecessary and the cost can be reduced.

  Below, this invention is demonstrated in detail based on embodiment shown in a figure. 1 shows a variable light distribution type headlamp driving device 1 according to the present invention (hereinafter abbreviated as “driving device 1”). A driving CPU 2 is also prepared in the driving device 1 of the present invention. Similar to the conventional example, the irradiation direction of the pair of headlamps 10a and 10b is changed by information from the outside such as the operation amount of the steering device input to the driving CPU 2.

  The signal input to the CPU 2 is not limited to the operation amount of the steering device described above. For example, information on the posture change of the vehicle body due to a static load change such as a loading amount, at the time of starting, at the time of deceleration, etc. Any signal may be used as long as it affects the irradiation direction of the headlamp, such as information on a posture change due to a dynamic load change.

  The CPU 2 is connected to a lamp driving device 3 such as a stepping motor. If the vehicle turns left according to the number of pulses output from the CPU 2, the operation of the steering device is performed. The headlamps 10a and 10b are rotated leftward by an amount corresponding to the amount to illuminate the front and improve the visibility in the traveling direction.

  Here, in the present invention, the CPU 2 incorporates a program for periodically accessing the abnormality detection circuit 4 from an appropriate terminal of the CPU 2, for example, outputs a pulse train having a predetermined arrangement to output the abnormality detection circuit. 4 is output. Note that the abnormality detection circuit 4 also has means for confirming that the pulse train from the CPU 2 is periodically output.

  In the abnormality detection circuit 4, an emergency position connected to the abnormality detection circuit 4 is assumed to be operating normally while a pulse train having a predetermined arrangement is periodically received from the CPU 2. A special instruction is not given to the device 5 or a normal signal is given. In this case, the emergency position generating device 5 does not perform any operation.

  Here, if a signal from the CPU 2 is not periodically transmitted to the abnormality detection circuit 4 or transmission is performed, but the pulse train arrangement is not a predetermined one, the abnormality detection circuit 4 Determines that an abnormality has occurred in the CPU 2 and switches the data selector circuit 6 connected between the CPU 2 and the lamp driving device 3 to the emergency position generating device 5 side.

Then, the abnormality detection circuit 4 causes the lamp driving device 3 to output the pulse train X stored in, for example, the ROM element 5a via the data selector circuit 6, and outputs the pulse train X to the lamp. This is input to the driving device 3 and then the pulse train Y is output. As a result, the headlamps 10a and 10b are directed in a predetermined direction to prevent inconvenience such as the occurrence of illusion on the oncoming vehicle.

  As described above, the pulse train X and the pulse train Y may be set at positions where the headlamps 10a and 10b do not interfere with the traveling of the host vehicle and do not cause an oncoming vehicle or the like to become dazzling. Therefore, if it is in the same state as a conventional passing lamp that has been fixed toward the front of the vehicle, it will be the same conditions as the current fixed headlamp and the purpose can be achieved Become.

  Here, the vehicle to which the variable light distribution type headlamp driving device 1 of the present invention is attached will be described as being for left-hand traffic. Then, the lamp driving device 3 faces the headlamp 10a (10b) in the direction of 21 in total, 10 steps from the front position to the left and right according to the operation amount of the steering device, as shown in FIG. It is assumed that the configuration can be changed.

  Further, the pulse train X generated from the emergency position generator 5 described above is such that the headlamps 10a and 10b are rotated one stage leftward, that is, on the road side per output, and the pulse train Y is The headlamps 10a and 10b are rotated by one stage, that is, on the opposite lane side with respect to one output. Therefore, in the case of a vehicle for right-hand traffic, a device that operates in the opposite direction may be formed.

  As apparent from the above description, when an abnormality is detected in the abnormality detection circuit 4 and the pulse train X from the emergency position generator 5 is output to the stepping motor drive circuit 7 via the data selector 6, the headlamp lamp 10a and 10b change the direction to the left by the number of pulse trains X output.

  Therefore, even if the headlamps 10a and 10b are directed to the right side (opposite lane side) to the maximum when an abnormality is detected in the CPU 2, if 20 pulse trains X are transmitted, the opposite side It reaches the maximum position on the left side (roadside). Therefore, in the present embodiment, the number of pulse trains X is determined as twenty.

  When the headlamps 10a and 10b are not directed to the right side (opposite lane side) as much as possible, by outputting 20 pulse trains X, an overrun occurs and the headlamps 10a and 10b are output. Therefore, a stopper 8 is provided at the specified position (10th left) so that the headlamp 10a (10b) does not turn to the left any more. Has been.

  Accordingly, in the present invention, the headlamp 10a (10b) can be obtained by inputting 20 pulse trains X that are directed leftward regardless of the direction of the headlamp 10a (10b). ) Will be left as far as possible. That is, the stopper 8 position is reached.

  As described above, the abnormality detection circuit 4 first instructs the emergency position generator 5 to output a driving pulse train X to be directed leftward, and after the output is performed, the abnormality detection circuit 4 is directed rightward. Command the output of the pulse train Y for driving. The pulse train Y may be held in advance in the ROM element 5a in the same manner as the pulse train X.

  As is clear from the above description, the output of the driving pulse train Y that is directed to the right starts from the state in which the headlamps 10a and (10b) are always in contact with the stopper 8. That is, the headlamps 10a and (10b) are started from a state in which they face the leftmost side.

  Since the number of driving pulse trains Y directed to the right is 10, the left and right headlamps 10a and 10b both face the front of the vehicle, and The abnormality detection circuit 4 stops the subsequent operation while switching the data selector 6 to the emergency position generator 5 side. Therefore, the headlamp is fixed toward the front direction of the vehicle, which is the emergency position of the drive device 1 for the variable light distribution type headlamp.

  By operating the abnormality detection circuit 4 described above, the left and right headlamps 10a and 10b are fixed in a state of facing the front of the vehicle. It is exactly the same as the passing headlamp. Therefore, when traveling at night, the standard as a headlamp is satisfied, and there is no difference from the fixed type. Therefore, the CPU 2 can be fully used until the CPU 2 is repaired, and the related standards are also satisfied.

  In the above description, it has been described that the left and right headlamps 10a and 10b rotate to the left by outputting the pulse train X and rotate to the right by outputting the pulse train Y. However, the pulse train X is output. As a result, the left headlamp 10a is rotated to the right, and the right headlamp 10b is rotated to the left. In other words, it rotates inward of the vehicle and outputs a pulse train Y, thereby rotating the left headlamp 10a to the left and the right headlamp 10b to the right, that is, rotating outward of the vehicle. It is also possible to adopt a circuit configuration. In this case, X in FIG. 2 represents the movement in the inner direction, Y represents the movement in the outer direction, and 8 represents a stopper in the inner direction.

  By doing so, the headlamps 10a and 10b when an abnormality is detected by the abnormality detection circuit 4 are rotated inward by the output of the pulse train X to reach the position of the stopper 8, and thereafter the output of the pulse train Y is output. Thus, each of them rotates outwardly to move toward the front, and the left and right movements are good both mechanically and in illumination.

  In addition, in order to simplify the explanation and facilitate understanding, the operation explanatory diagram of the lamp driving device in FIG. 2 has a configuration in which the direction can be changed from the front position to the left and right (inside / outside) 10 squares in a total of 21 directions. In the above description, 20 pulse trains X and 10 pulse trains Y are generated from the emergency position generator 5, but the present invention is not limited to this.

  The configuration example shown in FIG. 1 and FIG. 2 is one example, and the abnormality detection circuit 4, the emergency position generator 5, the ROM element 5a, the data selector 6 and the like can be freely formed as one IC. The gist of the present invention is not impaired. Furthermore, the stepping motor drive circuit 7 can also be integrated.

  In addition, the CPU 2 used in the vehicle is often used in a noisy environment and is likely to cause program runaway or malfunction due to noise, so it is called WDT (Watch dog timer), etc. In many cases, a circuit that resets the CPU 2 and restarts the CPU 2 to maintain stability is added.

  In such a case, for example, when an abnormality is detected even once in the abnormality detection circuit 4, the above procedure may be entered, and the headlamps 10a, 10b may be fixed in the vehicle front direction, or If the output to the abnormality detection circuit 4 of the next round is recovered normally, the above procedure is omitted, and when the abnormality detection circuit 4 detects an abnormality two or more times, the headlamps 10a, 10b You may make it fix.

  As described above, since the abnormality detection circuit 4 is provided, an AFS type headlight that directs the irradiation direction of the headlamps in the traveling direction according to the operation amount of the steering device is provided by one CPU 2. This solves the problem that two CPUs are simply used to monitor the malfunction of the CPU, and the drive device 1 must be increased in cost.

  In the present invention, the stepping motor of the lamp driving device 3 has been described as a parallel input type. However, this may be a serial input type stepping motor or, for example, a drive using a rotary encoder or the like. Any device may be used as long as it can control the direction with a predetermined accuracy. Further, when the CPU 2 fails, the headlamps 10a and 10b can be freely used as long as the operation can be guaranteed even when the CPU 2 fails.

1 is a schematic wiring diagram showing a configuration of a variable light distribution type headlamp driving apparatus according to the present invention. It is explanatory drawing which similarly shows operation | movement of the part of the lamp drive device of the drive device of the variable light distribution type headlamp which concerns on this invention. It is a schematic wiring diagram which shows the example of a structure of the drive device of the variable light distribution type headlamp of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Variable light distribution type headlamp drive device 2 ... CPU
DESCRIPTION OF SYMBOLS 3 ... Lamp drive device 4 ... Abnormality detection circuit 5 ... Emergency position generator 5a ... ROM element 6 ... Data selector 7 ... Stepping motor drive circuit 8 ... Stopper 10a, 10b ... Headlamp lamp

Claims (1)

In the drive device of the variable light distribution type headlamp which is configured by rotating the headlamp lamp and irradiating the traveling direction of the vehicle by operating the steering device, the drive device includes an operation amount of the steering device. a CPU for calculating the amount of rotation of the headlight lamp from a stepping motor drive circuit for rotating the headlight lamp by driving the stepping motor based on a calculation result of the CPU, the abnormality detection to be connected to the CPU A circuit, an emergency position generator that outputs an emergency position signal according to a signal from the abnormality detection circuit, and a data selector circuit that switches between connecting the CPU or the emergency position generator to the stepping motor drive circuit; consists, the abnormality detection circuit monitors a signal from the periodic or always in CPU, said CPU when said signal is a predetermined signal Always judged to be operating, the data selector circuit wherein the CPU is connected to the stepping motor driving circuit, the data selector circuit when an abnormality is detected in the signal, it is determined that an abnormality has occurred in the CPU is By switching from the connection between the CPU and the stepping motor drive circuit to the connection between the emergency position generator and the stepping motor drive circuit, the headlamp lamp is set to the emergency position. 2. A variable light distribution type headlamp driving apparatus, wherein two headlamps are controlled by one CPU.

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