Whole vehicle controller high side lamp control disconnection detection circuit

Abstract

The utility model discloses a vehicle control unit high side lamp control broken line detection circuit, a sampling resistor is connected in series on a vehicle control unit high side lamp control driving circuit, and the broken line detection circuit comprises a differential amplification circuit, an active filter, a passive filter and a main detection chip which are connected in sequence; the two ends of the sampling resistor are connected with the two input ends of the differential amplification circuit, the differential amplification circuit amplifies the voltage difference between the two ends of the sampling resistor, and after first-order active filtering and first-order passive filtering are conducted, the voltage is output to an AD analog acquisition port of the main detection chip to be detected and judged. According to the vehicle control unit high-side lamp control broken line detection circuit provided by the utility model, the design of a high-side output broken line detection circuit is added, and whether a corresponding lamp control loop has abnormal conditions such as a broken line fault or overcurrent can be timely and effectively found.

Description

Technical Field

[0001] The utility model relates to the field of high-side lamp control of a vehicle controller, and particularly relates to a high-side lamp control open-circuit detection circuit for a vehicle controller. Background Art

[0002] As a core component of an electric motorcycle vehicle system, a vehicle controller (ECU) is used to coordinate other in-vehicle modules such as a vehicle battery management system module (BMS), a motor controller module (MCU), an instrument display (ICM), an intelligent Internet of Things module (IOT), an anti-lock braking system (ABS), an on-board charger (OBC), a high-voltage power distribution module (PDU), and an on-board diagnostic module (OBD) through a specific vehicle local area network (CAN) communication protocol for system control, so as to achieve intelligent vehicle control of the electric motorcycle.

[0003] In the existing high-side lamp control technology of a vehicle controller, the design of an open-circuit detection circuit for high-side output is lacking, and it is impossible to timely and effectively detect whether there are abnormal situations such as open-circuit faults or overcurrent in the corresponding lamp control circuit. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a high-side lamp control open-circuit detection circuit for a vehicle controller, which adds the design of an open-circuit detection circuit for high-side output and can timely and effectively detect whether there are abnormal situations such as open-circuit faults or overcurrent in the corresponding lamp control circuit.

[0005] The technical solution of the utility model is as follows:

[0006] A high-side lamp control open-circuit detection circuit for a vehicle controller, a sampling resistor R47 is connected in series on the driving circuit of the high-side lamp control of the vehicle controller, and the open-circuit detection circuit includes a differential amplification circuit, an active filter, a passive filter, and a main detection chip connected in sequence;

[0007] OHLAMP1_P and OHLAMP1_N at both ends of the sampling resistor R47 are connected to two input ends of the differential amplification circuit. The differential amplification circuit amplifies the voltage difference at both ends of the sampling resistor R47, and then after first-order active filtering and then first-order passive filtering, it is output to the AD analog acquisition port of the main detection chip for detection and judgment.

[0008] Preferably, the differential amplification circuit adopts an LM358 operational amplifier U1. The non-inverting input end and the inverting input end of the operational amplifier U1 are respectively connected to OHLAMP1_P and OHLAMP1_N at both ends of the sampling resistor R47 through resistors R54 and R49, and a resistor R46 is connected between the output end and the inverting input end of the operational amplifier U1.

[0009] Preferably, the non-inverting input end of the operational amplifier U1 is also connected to a reference voltage of 1.24V through a resistor R56.

[0010] Preferably, the reference voltage of 1.24V is generated by a reference circuit, which includes 12V_AUX auxiliary power supply, resistor R76, and zener diode U7. The 12V_AUX auxiliary power supply is grounded through resistor R76 and zener diode U7 connected in sequence, and the zener diode U7 outputs a reference voltage of 1.24V.

[0011] Preferably, the 12V_AUX auxiliary power supply also provides the operating voltage for operational amplifier U1, and the 12V_AUX auxiliary power supply is turned off when sampling is not required.

[0012] Preferably, the output end of the driving circuit of the vehicle controller high-side lamp control is connected to transient suppression diode D26 for electrostatic protection of the external interface, and the output end of the open-circuit detection circuit is connected to zener diode D25 for overvoltage protection of the main detection chip pin.

[0013] Preferably, the vehicle controller outputs a 12V voltage to the driving circuit of the high-side lamp control.

[0014] The advantages of the present utility model are as follows:

[0015] 1. The present utility model provides an open-circuit detection circuit for the high-side lamp control of a vehicle controller, which adds the design of an open-circuit detection circuit for the high-side output, and can timely and effectively detect whether there are abnormal conditions such as open-circuit faults or overcurrents in the corresponding lamp control loop.

[0016] 2. The 12V_AUX in the open-circuit detection circuit and the reference circuit of the present utility model is a controllable 12V auxiliary power supply. When sampling is not required, the 12V_AUX auxiliary power supply can be turned off to reduce unnecessary power consumption, and the presence or absence of 12V_AUX does not affect the normal lamp control output.

[0017] 3. A transient suppression diode is placed at the output end of the lamp control of the present utility model for electrostatic protection of the external interface to ensure that the internal devices are not damaged, and a zener diode is placed at the output end of the open-circuit detection circuit for overvoltage protection of the internal main chip pin to prevent overvoltage damage to the internal main chip. Description of the Drawings

[0018] The present utility model will be further described below in conjunction with the drawings and embodiments:

[0019] Figure 1 It is the schematic diagram of the 12V high-side lamp control driving circuit in the embodiment;

[0020] Figure 2 It is the schematic diagram of the open-circuit detection circuit in the embodiment;

[0021] Figure 3 It is the schematic diagram of the 1.24V reference circuit.

[0022] Figure 4This is the limit parameter table of LM358. Specific implementation mode

[0023] Due to the common ground design of the external lamp components, in order to drive the external lamp to light, the vehicle control unit (VCU) needs to have a controllable high-side 12V output inside. As Figure 1 shown, a sampling resistor R47 is connected in series on the driving circuit of the high-side lamp control of the vehicle control unit.

[0024] As Figure 2 shown, the open-circuit detection circuit includes a differential amplifier circuit, an active filter, a passive filter, and a main detection chip connected in sequence; the two ends OHLAMP1_P and OHLAMP1_N of the sampling resistor R47 are connected to the two input ends of the differential amplifier circuit. The differential amplifier circuit amplifies the voltage difference at both ends of the sampling resistor R47, and then performs first-order active filtering and then first-order passive filtering, and outputs it to the AD analog acquisition port of the main detection chip for detection and judgment.

[0025] The differential amplifier circuit uses the LM358 operational amplifier U1. The non-inverting input terminal and the inverting input terminal of the operational amplifier U1 are respectively connected to the two ends OHLAMP1_P and OHLAMP1_N of the sampling resistor R47 through resistors R54 and R49. A resistor R46 is connected between the output terminal and the inverting input terminal of the operational amplifier U1.

[0026] The non-inverting input terminal of the operational amplifier U1 is also connected to a reference voltage of 1.24V through a resistor R56. As Figure 3 shown, the reference voltage of 1.24V is generated by a reference circuit. The reference circuit includes a 12V_AUX auxiliary power supply, a resistor R76, and a voltage regulator tube U7. The 12V_AUX auxiliary power supply is grounded through the resistor R76 and the voltage regulator tube U7 connected in sequence, and the voltage regulator tube U7 outputs a reference voltage of 1.24V.

[0027] Considering that the current in the lamp control loop is small, in order to accurately identify the differences in the loop current in the normal lamp driving situation, open-circuit situation, and over-current situation, the operational amplifier LM358 with wide voltage input is selected. The limit parameters of the operational amplifier LM358 refer to the limit parameter table as Figure 4 shown, and it meets the voltage input for normal driving output of 12V.

[0028] Perform differential acquisition on the voltage at both ends of the sampling resistor R47 in Figure 1 shown. Then amplify the differential voltage ΔV by 10 times (the amplification factor is determined by the resistance values of R46, R49, R54, and R56), add the reference voltage of 1.24V (for the circuit generating the reference voltage of 1.24V, see Figure 3 ), and then perform first-order active filtering and then first-order passive filtering, and output it to the AD analog acquisition port of the main chip for detection and judgment. The specific calculation formula is as follows:

[0029]

[0030] It can be seen that in the case of no drive output, since there are two pull-down resistors, R52 and R53, at both ends of the sampling resistor, V OHLAMP1_P = V OHLAMP1_N = 0V at this time. Furthermore, in this case When the drive output is normal, a small current in the 12V range passes through the sampling resistor, generating a weak voltage drop across the sampling resistor. At this time, V OHLAMP1_P > V OHLAMP1_N After being amplified by the operational amplifier,

[0031] In the later stage, it is recognized and compared by software and corresponding warning strategies are determined. When an external short-circuit fault occurs, a large current in the 12V range passes through the sampling resistor at this time, generating a voltage drop across the sampling resistor. At this time, V OHLAMP1_P > V OHLAMP1_N After being amplified by the operational amplifier, In the later stage, it is recognized and compared by software and corresponding protection strategies are determined.

[0032] In addition, the 12V_AUX in the sampling processing circuit and the reference circuit is an internally software-controllable 12V auxiliary power supply. When sampling is not required, the auxiliary power supply of the 12V_AUX can be turned off to reduce unnecessary power consumption. The presence or absence of the 12V_AUX does not affect the normal lamp control output. Finally, a D26 transient suppression diode is placed at the end of the lamp control output for electrostatic protection of the external interface to ensure that the internal components are not damaged. A D25 voltage regulator diode is placed at the end of the disconnection detection circuit for overvoltage protection of the internal main chip pins to prevent overvoltage damage to the internal main chip.

[0033] The above embodiments are only used to illustrate the technical concept and features of the present invention, and their purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and it should not be used to limit the protection scope of the present invention. All modifications made according to the spirit of the main technical solution of the present invention should be covered within the protection scope of the present invention.

Claims

1. A vehicle controller high side light control disconnection detection circuit, characterized in that: The driving circuit of the high-side light control of the vehicle controller is connected in series with a sampling resistor R47, and the disconnection detection circuit includes a differential amplifier circuit, an active filter, a passive filter, and a main detection chip connected in sequence; The two ends of the sampling resistor R47, OHLAMP1_P and OHLAMP1_N, are connected to the two input ends of the differential amplifier circuit. The differential amplifier circuit amplifies the voltage difference between the two ends of the sampling resistor R47, and then performs a first-order active filter and a first-order passive filter, and then outputs it to the AD analog acquisition port of the main detection chip for detection and judgment.

2. The vehicle controller high side light control disconnection detection circuit according to claim 1, characterized in that: The differential amplifier circuit adopts LM358 operational amplifier U1, the non-phase input terminal and the inverting input terminal of the operational amplifier U1 are connected to the two ends of the sampling resistor R47 OHLAMP1_P and OHLAMP1_N through resistors R54 and R49 respectively, and a resistor R46 is connected between the output terminal and the inverting input terminal of the operational amplifier U1.

3. The vehicle controller high side light control disconnection detection circuit according to claim 2, characterized in that: The non-inverting input terminal of the operational amplifier U1 is also connected to a reference voltage of 1.24V via a resistor R56.

4. The vehicle controller high side light control disconnection detection circuit according to claim 3, characterized in that: The 1.24V reference voltage is generated by a reference circuit, which includes a 12V_AUX auxiliary power supply, a resistor R76, and a voltage regulator U7. The 12V_AUX auxiliary power supply is grounded through the resistor R76 and the voltage regulator U7 connected in sequence, and the voltage regulator U7 outputs a 1.24V reference voltage.

5. The vehicle controller high side light control disconnection detection circuit according to claim 4, characterized in that: The 12V_AUX auxiliary power also provides operating voltage to the operational amplifier U1 , and the 12V_AUX auxiliary power is turned off when sampling is not required.

6. The vehicle controller high side light control disconnection detection circuit according to claim 1, characterized in that: The output end of the driving circuit of the high-side light control of the vehicle controller is connected to a transient suppression diode D26 for electrostatic protection of the external interface, and the end of the disconnection detection circuit is connected to a voltage regulator tube D25 for overvoltage protection of the main detection chip pin.

7. The vehicle controller high side light control disconnection detection circuit according to claim 1, characterized in that: The vehicle controller outputs a 12V voltage to the driving circuit of the high-side lamp control.

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