WO2020181717A1

WO2020181717A1 - Vehicle lamp control circuit and vehicle

Info

Publication number: WO2020181717A1
Application number: PCT/CN2019/100333
Authority: WO
Inventors: 蒋敏; 倪朋朋; 张杨; 汤海莲; 夏承军
Original assignee: 常州星宇车灯股份有限公司
Priority date: 2019-03-13
Filing date: 2019-08-13
Publication date: 2020-09-17
Also published as: DE212019000432U1; CN109661076A; CN109661076B

Abstract

The present invention provides a vehicle lamp control circuit and a vehicle. The vehicle lamp control circuit comprises a plurality of vehicle lamp circuits and a control circuit; each vehicle lamp circuit comprises at least one LED lamp, an LED fault detection unit, and an LED driving unit; the LED fault detection unit generates a detection signal according to a fault state of each LED lamp in the corresponding vehicle lamp circuit, and comprises a fault detection result output end for outputting the detection signal; the LED driving unit comprises a driving signal input end for inputting an LED driving signal; the control circuit comprises a control chip; an input pin of the control chip is connected to the fault detection result output end of each vehicle lamp circuit, and an output pin of the control chip is connected to the driving signal input end of each vehicle lamp circuit. The control chip generates the corresponding LED driving signal according to the detection signal to drive turn-on or turn-off of the LED lamp in each vehicle lamp circuit. The vehicle lamp control circuit in the present invention can realize a vehicle lamp N-1 function, and is simple in circuit structure, low in circuit costs, and high in reliability and stability.

Description

Car light control circuit and vehicle

Technical field

The invention relates to the technical field of automobile electronics, in particular to a vehicle light control circuit and a vehicle.

Background technique

LED lamps have been widely used in the automotive industry. The driving safety of the car is the first priority. The ECE regulations clearly stipulate that when a single LED is extinguished, LED lights can continue to be used if they can still meet the light distribution requirements of the corresponding functions; if the light distribution requirements cannot be met, the lights need to be fed back to the main body control Unit failure information reminds the user to replace car parts in time to ensure safe driving. However, because the location of each LED in the lamp is different, it is difficult to ensure that the light distribution of the entire lamp can meet the requirements of ECE regulations after any one LED fails.

Therefore, many automakers currently require LED lights to implement the N-1 function of the lights, that is, if any one LED fails, all the LEDs are off. However, the current circuits and control logic used to realize the N-1 function of the car light are relatively complex, costly, and have low reliability. In addition, the performance stability of the analog circuit under extreme temperature environments and extreme voltages is relatively low.

Summary of the invention

The present invention provides a vehicle light control circuit and a vehicle in order to solve the current technical problem that the circuits and control logic used to realize the N-1 function of the vehicle light are relatively complicated.

The technical scheme adopted by the present invention is as follows:

A vehicle light control circuit includes a plurality of vehicle light circuits and a control circuit. Each vehicle light circuit includes at least one LED light, an LED failure detection unit and an LED drive unit. The LED failure detection unit A detection signal is generated for the failure state of each LED lamp in the LED, the LED failure detection unit includes a failure detection result output terminal for outputting the detection signal, and the LED driving unit includes a driving signal input terminal for inputting the LED driving signal , The control circuit includes a control chip, the input pin of the control chip is connected to the output terminal of the fault detection result in each of the vehicle light circuits, and the output pin of the control chip is connected to each of the vehicle light circuits. The drive signal input terminal in the vehicle light circuit is connected, and the control chip generates the corresponding LED drive signal according to the detection signal to drive the LED lamp in each vehicle light circuit to emit light or to extinguish.

Each of the vehicle light circuits includes an LED branch composed of one or more series-connected LED lights, and one end of the LED branch is connected to the vehicle light power supply.

The LED driving unit includes a first triode and a first NMOS tube, the collector of the first triode is connected to the other end of the LED branch, and the gate of the first NMOS tube is connected to the first One end of the resistor is connected, the other end of the first resistor is used as the drive signal input terminal, the source of the first NMOS transistor is grounded, and the source and gate of the first NMOS transistor are connected with a second A resistor, the drain of the first NMOS transistor is connected to the emitter of the first triode through a third resistor.

The LED fault detection unit includes a second NMOS tube and a first diode, the gate of the second NMOS tube is connected to the other end of the LED branch through a fourth resistor, and the source of the second NMOS tube The drain of the second NMOS transistor is connected to the vehicle light power supply through a fifth resistor, the anode of the first diode is connected to the drain of the second NMOS transistor, and the first two The cathode of the pole tube serves as the output terminal of the fault detection result.

The input pin of the control chip is connected to the fault detection result output terminal through a sixth resistor, and is grounded through a seventh resistor.

Each of the vehicle lamp circuits also includes one or more protection capacitors connected in parallel with each LED lamp.

The control chip also obtains the voltage of the vehicle light power supply, and generates the corresponding LED driving signal according to the voltage of the vehicle light power supply to drive the LED lights in each vehicle light circuit to emit light or to extinguish.

A vehicle includes the above-mentioned vehicle light control circuit.

The beneficial effects of the present invention:

The present invention performs LED lamp failure detection through LED failure detection units in multiple car lamp circuits, generates corresponding LED drive signals according to the detection signals through the control chip in the control circuit, and drives them through the LED drive units in multiple car lamp circuits The LED lights in each car light circuit are on or off, thus, the N-1 function of the car light can be realized through a relatively simple circuit structure, that is, when any LED light fails, all the LED lights are controlled to go out, which can effectively remind the user Replace parts in time to ensure driving safety. Because the circuit structure is simple, the circuit cost is low, and the reliability and stability are high.

Description of the drawings

Fig. 1 is a block diagram of a vehicle lamp control circuit according to an embodiment of the present invention;

Figure 2 is a circuit diagram of a car lamp circuit according to an embodiment of the present invention;

Figure 3 is a circuit diagram of a control circuit according to an embodiment of the present invention;

Fig. 4 is a software flowchart of vehicle lamp control according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

As shown in FIG. 1, the vehicle light control circuit of the embodiment of the present invention includes a plurality of vehicle light circuits 10 and control circuits 20. Wherein, each car light circuit 10 includes at least one LED lamp 11, an LED failure detection unit 12, and an LED drive unit 13. The LED failure detection unit 12 generates a detection signal according to the failure state of each LED lamp in the car light circuit. The detection unit 12 includes a fault detection result output terminal for outputting a detection signal, the LED driving unit 13 includes a driving signal input terminal for inputting an LED driving signal; the control circuit 20 includes a control chip, and the input pins of the control chip are connected to each vehicle. The output terminal of the fault detection result in the lamp circuit 10 is connected, and the output pin of the control chip is connected to the driving signal input terminal in each car light circuit 10. The control chip generates a corresponding LED driving signal according to the detection signal to drive each car The LED lamp in the lamp circuit 10 is lit or extinguished.

In an embodiment of the present invention, as shown in Figure 2, each car light circuit 10 includes one or more LED lights connected in series to form an LED branch (in the figure three LED lights LED1, LED2 and LED3 are Example), one end of the LED branch is connected to the lamp power supply VCC. The LED driving unit 13 includes a first transistor Q1 and a first NMOS transistor MOS1. The collector of the first transistor Q1 is connected to the other end of the LED branch. The gate of the first NMOS transistor MOS1 is connected to the first resistor R1. One end is connected, the other end of the first resistor R1 is used as the drive signal input terminal D-T4, the source of the first NMOS transistor MOS1 is grounded, and the second resistor R2 is connected between the source and the gate of the first NMOS transistor MOS1. The drain of an NMOS transistor MOS1 is connected to the emitter of the first transistor Q1 through a third resistor R3. The LED fault detection unit 12 includes a second NMOS tube MOS2 and a first diode D1. The gate of the second NMOS tube MOS2 is connected to the other end of the LED branch through a fourth resistor R4, and the source of the second NMOS tube MOS2 is grounded. The drain of the second NMOS transistor MOS2 is connected to the vehicle lamp power supply VCC through the fifth resistor R5, the anode of the first diode D1 is connected to the drain of the second NMOS transistor MOS2, and the cathode of the first diode D1 is used as a fault The test result output terminal N-1. In addition, as shown in Figure 2, each car light circuit 10 also includes one or more protective capacitors connected in parallel with each LED lamp (in the figure, three C1, C2, and C3 are connected in parallel with LED1, LED2, and LED3. As an example).

In an embodiment of the present invention, the model of the control chip may be KEA8. As shown in FIG. 3, the input pin PTB5 of the control chip MCU can be connected to the fault detection result output terminal N-1 through the sixth resistor R6, and grounded through the seventh resistor R7. The output pins PTB0, PTB1, PTB2, and PTB3 of the control chip MCU are respectively connected to the D-T2, D-T1, D-T4, and D-T3 terminals, that is, to the drive signal input terminals of different car light circuits. In addition, as shown in Figure 3, the VDD pin of the control chip MCU is connected to a 5V DC power supply. The PTA5 and PTA4 pins are connected to the 5V DC power supply through the eighth resistor R8 and the ninth resistor R9 respectively. The 5V DC power supply terminal is also connected to the 5V DC power supply through a capacitor. C4 is grounded, and the PTA5 pin is also grounded through capacitor C5. The VSS pin of the control chip MCU is connected to the ground, and the PTB4 pin is connected to the 5V DC power supply through the tenth resistor R10.

Based on the above circuit structure, the base voltage of the first transistor Q1 is 1.4V, because Q1 is in the normal open state, the voltage difference between the base and the emitter is 0.7V, the emitter voltage is 0.7V, that is, the third resistor R3 The voltage difference is 0.7V, and the current of the third resistor R3 is 0.7V/R3. Because the collector current of the transistor is the same as the emitter, the LED branch current is 0.7V/R3, and the LED is driven by a constant current. When the LED lights are working normally, the gate of the second NMOS tube MOS2 is high, MOS2 is turned on, the input of the first diode D1 is low, and the fault detection result output terminal N-1 is low; otherwise, When any one or more LED lights fails, the output terminal N-1 of the failure detection result is high.

Therefore, when the LED lamps in the plurality of vehicle lamp circuits 10 are all working normally, the fault detection result output terminal N-1 of the LED fault detection unit 12 outputs a low level, and the input pin of the control chip MCU in the LED drive unit 20 PTB5 detects a low level, and the output pins PTB0, PTB1, PTB2, and PTB3 of the control chip MCU output high levels to the D-T2, D-T1, D-T4, and D-T3 terminals respectively. Each car light circuit 10 The first NMOS tube MOS1 of the middle LED driving unit 13 is turned on, and the LED lights in each car light circuit normally emit light; when any one or more of the LED lights fails, the fault detection result output terminal N- of the LED fault detection unit 12 1 Output high level, the input pin PTB5 of the control chip MCU in the LED drive unit 20 detects a high level, and the output pins PTB0, PTB1, PTB2, and PTB3 of the control chip MCU are directed to D-T2, D-T1, and D respectively. -T4 and D-T3 terminals output low level, the first NMOS tube MOS1 of the LED driving unit 13 in each car light circuit 10 is turned off, and all the LED lights in the car light circuit are turned off to realize the car light circuit N-1 Features.

Correspondingly, the flow of the vehicle light control software executed by the vehicle light control circuit of the embodiment of the present invention is shown in FIG. 4. The embodiment of the present invention modularizes software design and development, and reduces the coupling between modules. The composition of the software includes two modules, the bottom driver (Bottom Driver) and the application (App). The bottom driver includes WDG, GPIO, Timer, CCP, ADC, Interrupt management and other modules. For the underlying driver module, seamless connection of the same platform is achieved. The upper application program is mainly the code formed by the call and logical relationship between the various modules, and the application module is hardware-independent, adopts C language modular programming design, adopts sequential execution method, and the main function execution has watchdog protection to prevent the program Failure, the system is safe, stable and efficient.

In addition, in an embodiment of the present invention, the control chip MCU can also obtain the voltage of the car light power supply, and generate corresponding LED driving signals according to the voltage of the car light power supply to drive the LED lights in each car light circuit to emit light or Extinguished. Specifically, when the voltage of the car lights is abnormal, the output pins PTB0, PTB1, PTB2, and PTB3 of the control chip MCU can output low level to the D-T2, D-T1, D-T4, and D-T3 terminals, respectively. The first NMOS tube MOS1 of the LED driving unit 13 in the car light circuit 10 is turned off, and all the LED lights in the car light circuit are turned off, thereby realizing circuit protection and improving circuit safety and stability.

According to the vehicle light control circuit of the embodiment of the present invention, the LED light fault detection is performed by the LED fault detection units in the multiple vehicle light circuits, and the corresponding LED driving signal is generated according to the detection signal through the control chip in the control circuit, and the corresponding LED driving signal is generated by the multiple The LED driving unit in the car light circuit drives the LED lights in each car light circuit to emit or extinguish. Therefore, the N-1 function of the car light can be realized through a relatively simple circuit structure, that is, to control all the LED lights when any LED light fails. The LED lights are off, which can effectively remind users to replace parts in time and ensure driving safety. Due to the simple circuit structure, the circuit has low cost, high reliability and stability.

Corresponding to the foregoing embodiment, the present invention also provides a vehicle.

The vehicle of the embodiment of the present invention includes the vehicle light control circuit described in any of the foregoing embodiments of the present invention. For specific implementation manners, refer to the foregoing embodiment. To avoid redundancy, details are not described herein again.

According to the vehicle of the embodiment of the present invention, the lamp N-1 function can be realized through a relatively simple circuit structure, that is, when any LED lamp fails, all the LED lamps are controlled to be turned off, which can effectively remind the user to replace parts in time and ensure driving safety. Due to the simple circuit structure, the circuit cost is lower, reliability and stability are higher.

In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of these features. The meaning of "plurality" means two or more than two, unless otherwise specifically defined.

In the present invention, unless otherwise clearly defined and defined, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. , Or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meaning of the above-mentioned terms in the present invention can be understood according to specific circumstances.

In the present invention, unless expressly stipulated and defined otherwise, the first feature “on” or “under” the second feature may be in direct contact with the first and second features, or the first and second features may be indirectly through an intermediary. contact. Moreover, the "above", "above" and "above" of the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the level of the first feature is higher than the second feature. The “below”, “below” and “below” of the second feature of the first feature may mean that the first feature is directly below or obliquely below the second feature, or it simply means that the level of the first feature is smaller than the second feature.

In the description of this specification, descriptions with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean specific features described in conjunction with the embodiment or example , Structure, materials or features are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples and the characteristics of the different embodiments or examples described in this specification without contradicting each other.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. And variations, the scope of the present invention is defined by the appended claims and their equivalents.

Claims

A vehicle light control circuit, characterized in that it comprises a plurality of vehicle light circuits and control circuits, each of the vehicle light circuits includes at least one LED lamp, an LED failure detection unit and an LED drive unit, and the LED failure detection unit is based on The fault state of each LED lamp in the vehicle lamp circuit generates a detection signal, the LED fault detection unit includes a fault detection result output terminal for outputting the detection signal, and the LED driving unit includes a detection signal for inputting an LED driving signal. Drive signal input terminal, the control circuit includes a control chip, the input pin of the control chip is connected to the fault detection result output terminal in each of the car light circuits, and the output pin of the control chip is connected to each The drive signal input terminal in the vehicle light circuit is connected, and the control chip generates the corresponding LED drive signal according to the detection signal to drive the LED light in each vehicle light circuit to emit light or to extinguish.
The vehicle light control circuit according to claim 1, wherein each of the vehicle light circuits includes an LED branch composed of one or more LED lights connected in series, and one end of the LED branch is connected to the vehicle light power supply.
The vehicle light control circuit according to claim 2, wherein the LED driving unit comprises a first triode and a first NMOS tube, and the collector of the first triode is connected to the LED branch. The other end is connected, the gate of the first NMOS transistor is connected to one end of the first resistor, the other end of the first resistor is used as the driving signal input end, the source of the first NMOS transistor is grounded, and the A second resistor is connected between the source and the gate of the first NMOS transistor, and the drain of the first NMOS transistor is connected to the emitter of the first triode through a third resistor.
The vehicle lamp control circuit according to claim 3, wherein the LED fault detection unit comprises a second NMOS tube and a first diode, and the gate of the second NMOS tube is connected to the all-in-one through a fourth resistor. At the other end of the LED branch, the source of the second NMOS tube is grounded, the drain of the second NMOS tube is connected to the vehicle light power supply through a fifth resistor, and the anode of the first diode is connected to the The drain of the second NMOS tube is connected, and the cathode of the first diode is used as the output terminal of the fault detection result.
The vehicle lamp control circuit according to claim 4, wherein the input pin of the control chip is connected to the fault detection result output terminal through a sixth resistor, and is grounded through a seventh resistor.
The vehicle light control circuit according to claim 4, wherein each of the vehicle light circuits further comprises one or more protection capacitors connected in parallel with each LED light.
The vehicle light control circuit according to claim 5, wherein the control chip also obtains the voltage of the vehicle light power supply, and generates the corresponding LED drive signal according to the voltage of the vehicle light power supply to drive The LED lights in each of the vehicle light circuits are on or off.
A vehicle, characterized by comprising the vehicle light control circuit according to any one of claims 1-7.