JP2004155249A - Irradiation direction control device of vehicular lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply perform a failure diagnosis before driving on a motor for driving, in an irradiation direction control device of a vehicular lighting fixture. <P>SOLUTION: This irradiation direction control device has a stepping motor 9 as a driving source for controlling an optical axis direction of the lighting fixture. The device is provided with a current supply circuit17 for supplying current for the failure diagnosis to a motor coil 9a and a detection circuit 18 for detecting current flowing in the coil 9a. When the current for the failure diagnosis is made to flow and when the current is not made to flow, the failure diagnosis before driving the motor is performed from detected current by the detection circuit 18. <P>COPYRIGHT: (C)2004,JPO

Description

【００３４】
尚、網掛けの部分が故障状態を表している（つまり、出力値「Ｌｏ」に対して入力値「Ｌｏ」の場合及び出力値「Ｈｉ」に対して入力値「Ｈｉ」の場合。）。
【００３５】
モータ９が正常である場合には、「ＯＵＴ」の出力値に対して期待通りの「ＩＮ」の入力値が返されるので（本例では、正常の場合、出力値の論理否定が入力値とされる。）、この場合には、「ＯＵＴ」からの「Ｈｉ」レベル信号が電源供給回路１７に供給されてトランジスタ１９、２０がオン状態となる（励磁コイル９ａの端子Ｔ１にＶｈが供給される。）。
【００３６】
診断処理の手順をまとめると下記のようになる。
【００３７】
（１）モータ駆動前に、制御部１５から電流供給回路１７にＬｏ又はＨｉレベル信号を出力する
（２）検出回路１８から制御部１５への入力信号を調べる
（３）制御部１５の出力信号と入力信号とが同レベルの信号のとき（論理レベルが同じ場合）に、モータ故障と判断する。
【００３８】
このような電流供給回路１７及び検出回路１８は、モータ内における各相のコイル毎に付設されているので、詳細な故障診断が可能である。例えば、２相間ショートを検出するには、同一モータ内における、Ａ相の故障診断時に、Ｂ相のコイルに電流が流れたどうかを調べれば良い。Ａ相コイルにのみ電流が流れていれば問題ないが、本来流れる筈のないＢ相コイルに電流が流れていることが検出された場合には、ショートの発生と診断される。
【００３９】
以上のように、モータ９の励磁コイル９ａに対して、片方の端子Ｔ１からの微小電流を流すための電流供給回路１７と、励磁コイル９ａの他方の端子Ｔ２から微小電流を検出するための検出回路１８を設け、励磁コイル９ａへの電流供給が許可されていない状態において該コイルに流れる電流の有無を検出すること及び励磁コイル９ａへの電流供給が許可されている状態において該コイルに流れる電流の有無を検出することによって、モータ駆動前に故障診断を行うことができる。
【００４０】
そして、モータ９が故障していると診断された場合には、その旨の表示が車両運転者に通知され、制御部１５によりモータ９の駆動が禁止される。これにより、モータの脱調を回避することができるとともに、アクチュエータを構成する機構等の予期せぬ動きを防止することができる（照射光軸の向きによっては、車両走行の安全性に支障を来たす虞があるため。）。
【００４１】
尚、図２では、電流供給回路１７及び検出回路１８をそれぞれ個別素子で構成した例を示しているが、これらの回路をモータ駆動回路部１６とともに集積化することで１つのＩＣ内に収容する等、各種形態での実施が可能である。また、上記の例では、制御部１５の出力値に対する入力値の関係において、論理レベルが同じ場合にモータ故障と判断されるようにしたが、これに限らず、出力値と入力値の論理レベルが異なる場合にモータ故障と判断するといった、各種形態での実施が可能である。
【００４２】
【発明の効果】
以上に記載したところから明らかなように、請求項１に係る発明によれば、モータ駆動前の故障診断を簡易に行うことができる。そして、車両用灯具の照射方向制御への適用において、構成の複雑化や著しいコスト上昇を伴うことがない。
【００４３】
請求項２に係る発明によれば、同一モータ内において２相間のコイルショートが発生したか否かを容易に判断することができる。
【００４４】
請求項３に係る発明によれば、バイポーラ駆動のステッピングモータを用いた車両用灯具の照射方向制御装置への適用において、脱調回避のための故障診断を容易に行うことができる。
【００４５】
請求項４に係る発明によれば、故障原因を抱えたままの状態でモータが駆動されることがなく、予期しない駆動制御により車両走行の安全性に悪影響を及ぼす危険性が低減される。
【図面の簡単な説明】
【図１】本発明に係る照射方向制御装置の基本構成例を示す図である。
【図２】本発明に係る診断回路の構成例を示す図である。
【符号の説明】
１…車両用灯具の照射方向制御装置、９…モータ、９ａ…コイル、１０…駆動機構、１３…診断回路、１７…電流供給回路、１８…検出回路[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for diagnosing pre-drive failure of a motor in an irradiation direction control (or adjustment) device for a vehicle lamp using a motor.
[0002]
[Prior art]
In a vehicle headlamp, a device (so-called leveling) for controlling the direction of the illuminating optical axis in accordance with riding conditions, loading conditions, changes in the running posture of the vehicle, and the like, and enabling adjustment of the optical axis direction. Devices) are known.
[0003]
For example, in a lamp configured to change the optical axis direction of a movable reflecting mirror using a stepping motor as a driving source (for example, see Patent Document 1), open loop control of the stepping motor is performed. Before driving the motor, it is legally required to diagnose the failure of the motor in order to prevent loss of synchronization.
[0004]
[Patent Document 1]
JP-A-2002-127814 (FIG. 1)
[0005]
[Problems to be solved by the invention]
However, in the conventional apparatus, there is no effective means for performing a failure diagnosis before driving the motor, or there is a problem in that the configuration is complicated and the cost is increased. For example, when a bipolar driving stepping motor is used, a dedicated driving IC is generally used. However, when the IC performs a failure diagnosis only while the motor is driving, the motor is driven. Failure diagnosis cannot be performed before
[0006]
Therefore, an object of the present invention is to make it possible to easily perform a failure diagnosis before driving of a motor used in an irradiation direction control device for a vehicle lamp.
[0007]
[Means for Solving the Problems]
The present invention provides an irradiation direction control device for a vehicle lamp, comprising a motor driven by open-loop control and a driving mechanism driven by the motor to control or adjust the irradiation optical axis direction of the lamp. The configuration shown in FIG.
[0008]
A current supply circuit that supplies a current for failure diagnosis to the motor coil.
[0009]
・ A detection circuit that detects the current flowing through the motor coil.
[0010]
・ Pre-drive motor failure diagnosis based on the detection current detected by the detection circuit when the failure diagnosis current is supplied to the coil or the detection current detected by the detection circuit when the failure diagnosis current is not supplied to the coil Diagnostic circuit to perform.
[0011]
Therefore, according to the present invention, the failure diagnosis of the motor can be easily performed based on the detection current when the failure diagnosis current is supplied to the motor coil before the motor is driven or when the current is not supplied.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a basic configuration of an irradiation direction control device for a vehicle lamp according to the present invention. The figure shows a dynamic leveling device (such as an auto-leveling device) that performs irradiation direction control following a change in the attitude of the vehicle, and a load change according to the occupant's riding state and loading state. For a static device for adjusting the irradiation direction, both configurations are shown together for convenience.
[0013]
The irradiation direction control device 1 includes a vehicle attitude detection unit 2, a traveling detection unit 3, an operation input unit 4, an irradiation control unit 5, and a driving unit 6. The lamp 7 whose irradiation direction is controlled or adjusted by the irradiation control unit 5 via the driving unit 6 includes, for example, a head lamp, a fog lamp, and a cornering lamp in the case of an automobile lamp.
[0014]
As the vehicle attitude detecting means 2, for example, a vehicle height detecting means such as a vehicle height sensor is used to detect a vehicle height displacement related to an axle portion of a front wheel or a rear wheel of the vehicle. The detection signal is sent to the irradiation control means 5 and is used as information for determining the stopping posture and the running posture of the vehicle.
[0015]
The traveling detection means 3 detects the speed and acceleration of the vehicle, the speed of each wheel, and the like. A detection signal is sent to the irradiation control means 5 and the traveling state of the vehicle (stop or acceleration, constant speed, It is used as information for grasping deceleration.
[0016]
The operation input unit 4 includes, for example, an operation switch for manually controlling the irradiation direction of the lamp 7 and various switches necessary for operating the irradiation direction control device 1. The command signal from the operation input unit 4 is sent to the irradiation control unit 5 and processed.
[0017]
The irradiation control means 5 configured using a calculation means such as a computer generates a control signal necessary for controlling or adjusting the irradiation direction of the lamp 7 according to the signal from the detection means and the operation command signal. Then, this is sent to the driving means 6.
[0018]
The driving unit 6 is configured using a motor driving circuit 8 and receives a control signal from the irradiation control unit 5 and sends a driving signal to a motor 9 as a driving source. The leveling control of the lamp 7 is performed by a drive mechanism (or an adjustment mechanism) 10 of the irradiation optical axis driven by the rotation of the motor 9. In this example, the light source 11 and the reflecting mirror 12 are arranged in a lamp, and the optical axis direction can be changed within an allowable range by moving the reflecting mirror 12. For example, the direction of the irradiation optical axis is controlled by tilting the reflecting mirror 12 in a vertical plane including the optical axis by an actuator that moves along the optical axis direction as the motor 9 rotates. The present invention is not limited to this, and any configuration may be used as long as the optical component (for example, an inner lens or a shade) included in the lamp is driven by a motor to control or adjust the irradiation direction.
[0019]
The motor 9 is controlled in an open loop by a signal from the motor drive circuit 8, and for example, a stepping motor or a brushless motor is used. A diagnosis circuit 13 is provided for the motor 9 and performs a failure diagnosis before driving the motor 9. The diagnostic circuit 13 is provided, for example, in parallel with the motor drive circuit 8 and includes a circuit for supplying a small current to the motor coil and a circuit for detecting the small current. The information indicating the failure diagnosis result is sent to the irradiation control means 5, and the driving of the motor 9 is permitted or prohibited based on the information. That is, if the diagnosis circuit 13 diagnoses that the motor 9 has failed before the motor 9 is driven, the driving of the motor is prohibited.
[0020]
Although illustration is omitted, in addition to the above, a load state detecting means (seating sensor, load amount detecting sensor, etc.) for detecting a change in the load distribution of the vehicle due to a change in the number of passengers or the load in the vehicle is required. It is used according to.
[0021]
FIG. 2 shows a main part of a circuit configuration example 14 using a bipolar driving stepping motor. It should be noted that only one phase of the excitation coil 9a in the motor 9 is shown in FIG.
[0022]
In this example, a control signal is sent from the control unit 15 (or control interface unit) using a microcomputer or the like to the motor drive circuit unit 16. It is assumed that there is no circuit for use or a circuit for performing self-diagnosis only while the motor is being driven is incorporated.
[0023]
When the motor is driven, a current is supplied from the motor drive circuit section 16 to the exciting coil 9a. A current supply circuit 17 and a detection circuit 18 are provided as circuits necessary for performing a failure diagnosis before the motor 9 is driven. ing.
[0024]
The current supply circuit 17 is provided to supply a failure diagnosis current to the motor coil. In this example, the current supply circuit 17 includes an NPN transistor 19 and a PNP transistor 20.
[0025]
The base of the NPN transistor 19 whose emitter is grounded is supplied with a binary signal from the output terminal “OUT” of the control unit 15 via a resistor 21, and the collector of the transistor 19 is connected via a resistor 22 to the PNP transistor 20. Connected to the base. Note that a resistor 23 is inserted between the base and the emitter of the NPN transistor 19.
[0026]
The collector of the PNP transistor 20 is connected to the power supply line via the resistor 24, and is connected to one end “T1” of the exciting coil 9a. A predetermined power supply voltage “Vh” (= 12 V) is supplied to the emitter of the transistor 20, and a resistor 25 is inserted between the base and the emitter.
[0027]
The detection circuit 18 provided on the other end “T2” side of the exciting coil 9a is provided for detecting a current flowing through the exciting coil 9a. In this example, the NPN transistor 26 is configured to have a grounded emitter, and the detection voltage from the voltage dividing resistors 27 and 28 is supplied to the base of the transistor 26. That is, one end of the voltage dividing resistor 27 is connected to the terminal T2 of the exciting coil 9a, the other end of the voltage dividing resistor 27 is connected to the base of the NPN transistor 26, and grounded via the voltage dividing resistor 28. A predetermined power supply voltage “Vcc” (= 5 V) is supplied to the collector of the transistor 26 via the resistor 29, and the collector is connected to the input terminal “IN” of the control unit 15.
[0028]
A diagnostic circuit for performing a failure diagnosis before driving the motor based on the presence or absence or the detection level of the detection current by the detection circuit 18 is provided inside the control unit 15. A method of configuring the diagnostic circuit with hardware, and a method of determining the presence or absence of a failure and a failure state as software processing by a computer as in this example, but a calculation related to control of the illumination direction of the lamp requires a microcomputer or the like. The latter method is simpler when considering that it is performed by the used arithmetic processing.
[0029]
That is, the supply of the minute current to the exciting coil 9a is controlled by the binary signal (Hi or Lo) sent from the output terminal “OUT” of the control unit 15 to the current supply circuit 17, and the detection by the detection circuit 18 The result is input to the input terminal “IN” of the control unit 15 as a binary signal.
[0030]
In the initial state at the time of the pre-drive diagnosis, the output signal from “OUT” to the current supply circuit 17 is “Lo” (low) level, and when the motor 9 is normal, the signal input to “IN” is “Lo”. Hi ”(high) level. That is, in this case, the transistors 19 and 20 forming the current supply circuit 17 are off, and no current flows through the exciting coil 9a, so that the transistor 26 of the detection circuit 18 is off. Therefore, when the input signal to the terminal “IN” is at the “Lo” level, it is determined that a failure has occurred (the power supply voltage is applied to the load line to the exciting coil 9a, or the current is flowing due to a short circuit or the like). Is shown.).
[0031]
When the output signal from “OUT” to the current supply circuit 17 is at “Hi” level and the motor 9 is normal, the signal input to “IN” is at “Lo” level. That is, the transistors 19 and 20 constituting the current supply circuit 17 are on, a minute current flows through the exciting coil 9a, and the transistor 26 of the detection circuit 18 is on. Therefore, when the input signal to the terminal “IN” is at the “Hi” level, it is determined that a failure has occurred (indicating a ground fault or an open state of the coil connection line).
[0032]
The failure status includes abnormal voltage or current of the coil line (connection line), ground fault, and open, and a table of input / output values (a truth table) including a normal case is shown in Table 1 below.
[0033]
[Table 1]

[0034]
The shaded portion indicates a failure state (that is, the case where the input value is “Lo” for the output value “Lo” and the case where the input value is “Hi” for the output value “Hi”).
[0035]
When the motor 9 is normal, the input value of “IN” is returned as expected with respect to the output value of “OUT”. (In this example, when the motor 9 is normal, the logical negation of the output value is determined as the input value. In this case, the "Hi" level signal from "OUT" is supplied to the power supply circuit 17 to turn on the transistors 19 and 20 (Vh is supplied to the terminal T1 of the exciting coil 9a). ).
[0036]
The procedure of the diagnostic processing is summarized as follows.
[0037]
(1) Output a Lo or Hi level signal from the control unit 15 to the current supply circuit 17 before driving the motor. (2) Check an input signal from the detection circuit 18 to the control unit 15. (3) Output signal of the control unit 15. When the input signal and the input signal have the same level (when the logic levels are the same), it is determined that the motor has failed.
[0038]
Since such a current supply circuit 17 and a detection circuit 18 are provided for each coil of each phase in the motor, detailed failure diagnosis is possible. For example, to detect a short-circuit between two phases, it is only necessary to check whether or not a current has flowed in the B-phase coil during the A-phase failure diagnosis in the same motor. There is no problem if a current flows only through the A-phase coil, but if it is detected that a current flows through the B-phase coil which should not flow, it is diagnosed that a short circuit has occurred.
[0039]
As described above, the current supply circuit 17 for flowing a small current from one terminal T1 to the excitation coil 9a of the motor 9 and the detection for detecting a small current from the other terminal T2 of the excitation coil 9a. A circuit 18 is provided to detect the presence or absence of a current flowing through the exciting coil 9a in a state where the current supply to the exciting coil 9a is not permitted, and to detect a current flowing through the coil when the current supply to the exciting coil 9a is permitted. By detecting the presence or absence of a fault, a failure diagnosis can be performed before driving the motor.
[0040]
Then, when it is diagnosed that the motor 9 is out of order, an indication to that effect is sent to the vehicle driver, and the control unit 15 prohibits the driving of the motor 9. As a result, step-out of the motor can be avoided, and unexpected movement of a mechanism or the like constituting the actuator can be prevented. (Depending on the direction of the irradiation optical axis, the driving safety of the vehicle is hindered. There is a risk.)
[0041]
FIG. 2 shows an example in which each of the current supply circuit 17 and the detection circuit 18 is constituted by an individual element, but these circuits are integrated together with the motor drive circuit section 16 to be accommodated in one IC. It can be implemented in various forms such as. Further, in the above example, in the relationship between the input value and the output value of the control unit 15, when the logical level is the same, it is determined that the motor has failed. However, the present invention is not limited to this. If the values are different, it is possible to implement in various modes such as determining that the motor is out of order.
[0042]
【The invention's effect】
As is apparent from the above description, according to the first aspect of the invention, it is possible to easily perform a failure diagnosis before driving the motor. Further, in the application to the irradiation direction control of the vehicle lamp, the configuration is not complicated and the cost is not significantly increased.
[0043]
According to the invention according to claim 2, it is possible to easily determine whether or not a coil short between two phases has occurred in the same motor.
[0044]
According to the third aspect of the present invention, a failure diagnosis for avoiding loss of synchronism can be easily performed in an application to an irradiation direction control device of a vehicle lamp using a bipolar driving stepping motor.
[0045]
According to the invention according to claim 4, the motor is not driven while the cause of the failure remains, and the risk of adversely affecting the safety of the vehicle running due to unexpected drive control is reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a basic configuration of an irradiation direction control device according to the present invention.
FIG. 2 is a diagram showing a configuration example of a diagnostic circuit according to the present invention.
[Explanation of symbols]
DESCRIPTION OF REFERENCE NUMERALS 1: irradiation direction control device for vehicle lamp, 9: motor, 9a: coil, 10: drive mechanism, 13: diagnostic circuit, 17: current supply circuit, 18: detection circuit

Claims (4)

An irradiation direction control device for a vehicle lamp, comprising a motor driven by open-loop control and a driving mechanism driven by the motor to control or adjust the irradiation optical axis direction of the lamp.
A current supply circuit for supplying a failure diagnosis current to one end of the coil of the motor,
A detection circuit for detecting a current flowing through the coil from the other end of the coil;
Driving the motor based on the detection current detected by the detection circuit when the failure diagnosis current is supplied to the coil or the detection current detected by the detection circuit when the failure diagnosis current is not supplied to the coil An irradiation direction control device for a vehicle lamp, comprising a diagnosis circuit for performing a pre-failure diagnosis. The irradiation direction control device for a vehicle lamp according to claim 1,
The current supply circuit and the detection circuit are provided for each coil in the motor, and when a failure of one phase in the same motor is diagnosed as a current flowing in another phase coil, An irradiation direction control device for a vehicle lamp, wherein a diagnosis circuit diagnoses occurrence of a short circuit between two phases. An irradiation direction control device for a vehicle lamp according to claim 1 or 2,
An irradiation direction control device for a vehicle lamp, wherein the motor is a bipolar driving stepping motor. An irradiation direction control device for a vehicle lamp according to claim 1, claim 2 or claim 3,
An irradiation direction control device for a vehicle lamp, wherein the driving of the motor is prohibited if the motor is diagnosed as a failure before the motor is driven by the diagnostic circuit.

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