Circuit for detecting grounding open circuit and voltage offset of vehicle-mounted controller and in-vehicle arrangement mechanism thereof

Abstract

The utility model discloses a circuit for detecting grounding open circuit and voltage offset of a vehicle-mounted controller and an in-vehicle arrangement mechanism of the circuit. Comprising two detection modules, a GND1 detection module and a GND2 detection module are connected and then approach to a ground voltage NET0, a ground port is led out from each of the GND1 detection module and the GND2 detection module and is connected to the ground of a whole vehicle frame through a respective ground wire, and the two ground wires are independently and separately wired in a vehicle-mounted ECU controller. The outside of the ECU controller is in point connection with the ground of the whole vehicle frame, and the ground of the whole vehicle frame is connected with the negative electrode of the vehicle-mounted storage battery; when ground wire voltage offset such as ground wire open circuit exists in the two modules, the detection circuit can identify which ground wire has a fault through the change of an output voltage value. The device is suitable for the design that double ground wires exist in a passenger vehicle controller, can detect the connection condition of the ground wires of the controller in real time, and improves the use safety of the vehicle-mounted controller.

Description

Technical Field

[0001] The utility model discloses a signal detection circuit, in particular to a circuit for detecting grounding open circuit and voltage deviation of a vehicle-mounted controller and an in-vehicle arrangement mechanism thereof. Background Art

[0002] The ground wire is very important in the design of vehicle controllers as a power return line. The current mainstream design in chassis controllers is to connect the two power ground wires to the vehicle frame ground through ground wires, and then return to the negative pole of the vehicle battery through the frame ground. However, with the continuous improvement of automotive electronic functional safety requirements, detection of ground wire offset faults such as ground wire open circuits needs to be implemented to ensure the driver's safety needs. The general ground wire design does not have ground wire offset fault detection, which is bound to fail to meet safety design requirements. Utility Model Content

[0003] In order to solve the problems existing in the background technology, the purpose of the utility model is to provide a circuit for detecting ground open circuit and voltage deviation of a vehicle-mounted controller and its in-vehicle arrangement mechanism.

[0004] The technical solution of the utility model is achieved in this way:

[0005] The circuit is a logic reflux circuit, which includes two parts: a GND1 detection module and a GND2 detection module. After the GND1 detection module and the GND2 detection module are connected, they are close to the ground voltage NET0. At the same time, the GND1 detection module and the GND2 detection module each lead out a grounding port connected to the ground of the vehicle frame.

[0006] The GND1 detection module includes an operational amplifier U3 and multiple resistors and multiple capacitors. Resistors R1, R12 and R3 are connected in series and then connected in parallel to the two ends of capacitor C4. Capacitors C1 and C2 are connected in series and then connected in parallel to the two ends of capacitor C4. One end of capacitor C4 is connected to the negative input end of operational amplifier U3 through resistors R5 and R11. The other end of capacitor C4 is connected to the positive input end of operational amplifier U3 through resistors R6 and R8. The end between resistors R5 and R11 is connected to the positive input end of operational amplifier U3 through resistor R9. 3, the output end of the operational amplifier U3 is connected to the external first voltage acquisition port ADC_GND1; the end led between the resistor R12 and the resistor R3, the end led between the capacitor C1 and the capacitor C2, and the negative power supply terminal of the operational amplifier U3 are all connected to the near-ground voltage NET0, the positive power supply terminal of the operational amplifier U3 is connected to the power supply voltage, the output end of the operational amplifier U3 is connected to the near-ground voltage NET0 after passing through the resistor R10 and the capacitor C5, and the end led between the resistor R1 and the resistor R12 is used as the first ground port GND_1;

[0007] The GND2 detection module includes an operational amplifier U4 and multiple resistors and multiple capacitors. Resistors R14, R21 and R13 are connected in series and connected in parallel to both ends of capacitor C8. Capacitors C6 and C7 are connected in series and connected in parallel to both ends of capacitor C8. One end of capacitor C8 is connected to the negative input end of operational amplifier U4 through resistors R15 and R20. The other end of capacitor C8 is connected to the positive input end of operational amplifier U4 through resistors R16 and R17. The end between resistors R16 and R17 is connected to the positive input end of operational amplifier U4 through resistor R18. The output end of the operational amplifier U4 is connected to the external second voltage acquisition port ADC_GND2; the end led out between the resistor R21 and the resistor R13, the end led out between the capacitor C6 and the capacitor C7, and the negative power supply terminal of the operational amplifier U4 are all connected to the near-ground voltage NET0, the positive power supply terminal of the operational amplifier U3 is connected to the power supply voltage, the output end of the operational amplifier U4 is connected to the near-ground voltage NET0 after passing through the resistor R19 and the capacitor C9, and the end led out between the resistor R21 and the resistor R14 serves as the second ground port GND_2.

[0008] The near-ground voltage NET0 is a very low voltage.

[0009] In the GND1 detection module, resistor R12 is a current sampling resistor, resistor R11 and resistor R8 are both current limiting resistors; resistor R1 and capacitor C1 form a first-order low-pass filter, resistor R3 and capacitor C2 form a first-order low-pass filter, resistor R9 and operational amplifier U3 form a negative feedback amplifier circuit; resistor R10 is used to stabilize the output potential;

[0010] In the GND2 detection module, resistor R21 is a current sampling resistor, resistor R20 and resistor R17 are both current limiting resistors; resistor R13 and capacitor C6 form a first-order low-pass filter, resistor R14 and capacitor C7 form a first-order low-pass filter, resistor R18 and operational amplifier U4 form a negative feedback amplifier circuit; resistor R19 is used to stabilize the output potential.

[0011] The two ground ports GND_1 and GND_2 are connected to the vehicle frame ground through their own ground wires. The two ground wires are routed independently in the vehicle-mounted ECU controller and are point-connected to the vehicle frame ground outside the ECU controller. The vehicle frame ground is connected to the negative pole of the vehicle battery.

[0012] 2. A layout mechanism of a vehicle controller grounding circuit in the vehicle:

[0013] The above logic return circuit is arranged in the ECU controller, and the two grounding ports of the logic return circuit are both connected to the ground of the metal vehicle frame, and the negative pole of the vehicle battery is also connected to the ground of the metal vehicle frame.

[0014] The ECU controller also includes two power return circuits, and the grounding ends of the two power return circuits are respectively connected to the two grounding ports of the logic return circuit and then connected to the ground of the metal vehicle frame.

[0015] The two grounding ports of the logic return circuit, the grounding terminals of the two power return circuits and the ground of the metal vehicle frame form a grounding network.

[0016] The innovation of the utility model lies in that the detection circuit composed of an operational amplifier and a current sampling resistor can detect the connection fault of the ground wire in real time, and finally realizes the rapid detection of the open ground circuit and voltage offset of the vehicle controller, so that the functional safety level of the controller can be improved.

[0017] When there is a ground line voltage deviation between two modules, for example, a ground line is open, the detection circuit of the utility model can identify which ground line has a fault by changing the output voltage value.

[0018] The utility model collects loop current through a sampling resistor and amplifies it through an operational amplifier, and then outputs a corresponding voltage to the ADC analog-to-digital conversion port of the microcontroller unit MCU. By comparing the output voltage values ​​of the two groups of ground wires and checking each other, it can be concluded whether the current ground wire is well connected.

[0019] The beneficial effects of the utility model are:

[0020] The utility model provides reliable ground wire detection for the design of ground wires in a passenger car controller, and can accurately and quickly identify which ground wire has a fault and whether it is well connected.

[0021] The utility model is suitable for the design of double-path ground wires in the passenger car controller, and can detect the connection status of the controller ground wire in real time, thereby improving the safety of the vehicle-mounted controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the internal and external ground wire connections of the controller.

[0023] Figure 2 The schematic diagram of a circuit for detecting ground open circuit and voltage offset of an on-board controller is shown in FIG. DETAILED DESCRIPTION

[0024] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0025] The specifically implemented circuit is a logic reflux circuit, which includes two parts: a GND1 detection module and a GND2 detection module. After the GND1 detection module and the GND2 detection module are connected, they are close to the ground voltage NET0. At the same time, the GND1 detection module and the GND2 detection module each lead out a grounding port connected to the ground of the vehicle frame.

[0026] The circuit structure of the GND1 detection module is the same as that of the GND2 detection module, and the parameter values ​​of each component are the same and symmetrically arranged.

[0027] The GND1 detection module includes an operational amplifier U3 and multiple resistors and multiple capacitors. Resistors R1, R12 and R3 are connected in series and connected in parallel to both ends of capacitor C4. Capacitors C1 and C2 are connected in series and connected in parallel to both ends of capacitor C4. One end of capacitor C4 is connected to the negative input end of operational amplifier U3 through resistors R5 and R11, and the other end of capacitor C4 is connected to the positive input end of operational amplifier U3 through resistors R6 and R8. The end between resistors R5 and R11 is connected to the output end of operational amplifier U3 through resistor R9. The output end of the operational amplifier U3 is connected to the first voltage acquisition port ADC_GND1 of the external ECU controller; the end between the resistor R12 and the resistor R3, the end between the capacitor C1 and the capacitor C2, and the negative power supply terminal of the operational amplifier U3 are all connected to the near-ground voltage NET0, the positive power supply terminal of the operational amplifier U3 is connected to the power supply voltage 5V, the output end of the operational amplifier U3 is connected to the near-ground voltage NET0 after passing through the resistor R10 and the capacitor C5, and the end between the resistor R1 and the resistor R12 is used as the first ground port GND_1.

[0028] Specifically, Figure 2As shown, the No. 1 positive input terminal of the operational amplifier U3 is connected to the No. 2 pin of the resistor R8, the No. 1 pin of the resistor R8 is connected to the No. 2 pin of the resistor R6, the No. 1 pin of the resistor R6 is connected to the No. 1 pin of the capacitor C4, the No. 1 pin of the capacitor C2, and the No. 2 pin of the resistor R3. The No. 2 pin of the capacitor C4 is connected to the No. 1 pin of the resistor R5, the No. 2 pin of the capacitor C1, and the No. 2 pin of the resistor R1. The No. 2 pin of the capacitor C2 is connected to the No. 1 pin of the capacitor C1 to the network NET_0. The No. 1 pin of the resistor R3 is connected to the No. 1 pin of the resistor R12 and the No. 2 pin of the resistor R21 to the NET_0 network. The No. 1 pin of the resistor R1 and the No. 2 pin of the resistor R12 are connected to the ground network GND_1; the No. 2 negative input terminal pin of the operational amplifier U3 is connected to the No. 1 pin of the resistor R11, and the No. 2 pin of the resistor R11 is connected to the No. 2 pin of the resistor R5 and the No. 1 pin of the resistor R9. Pin 2 of resistor R9 and pin 2 of resistor R10, pin 2 of capacitor C5, and output pin 5 of operational amplifier U3 are all connected to network ADC_GND1. Pin 1 of resistor R10 and pin 1 of capacitor C5 are connected to network NET_0. Pin 3 of operational amplifier U3 is connected to power supply network 5V, and pin 4 of the operational amplifier is connected to network NET_0.

[0029] The GND2 detection module includes an operational amplifier U4 and multiple resistors and multiple capacitors. Resistors R14, R21 and R13 are connected in series and connected in parallel to the two ends of capacitor C8. Capacitors C6 and C7 are connected in series and connected in parallel to the two ends of capacitor C8. One end of capacitor C8 is connected to the negative input end of operational amplifier U4 through resistors R15 and R20. The other end of capacitor C8 is connected to the positive input end of operational amplifier U4 through resistors R16 and R17. The end between resistors R16 and R17 is connected to the input of operational amplifier U4 through resistor R18. The output end of the operational amplifier U4 is connected to the second voltage acquisition port ADC_GND2 of the external ECU controller; the end between the resistor R21 and the resistor R13, the end between the capacitor C6 and the capacitor C7, and the negative power supply terminal of the operational amplifier U4 are all connected to the near-ground voltage NET0, the positive power supply terminal of the operational amplifier U3 is connected to the power supply voltage 5V, the output end of the operational amplifier U4 is connected to the near-ground voltage NET0 after passing through the resistor R19 and the capacitor C9, and the end between the resistor R21 and the resistor R14 is used as the second ground port GND_2.

[0030] Specifically, Figure 2As shown, the No. 1 positive input terminal of the operational amplifier U4 in the GND2 detection module is connected to the No. 2 pin of the resistor R20, the No. 1 pin of the resistor R20 is connected to the No. 2 pin of the resistor R15, the No. 1 pin of the resistor R15 is connected to the No. 2 pin of the capacitor C8, the No. 2 pin of the capacitor C6, and the No. 2 pin of the resistor R13. The No. 1 pin of the capacitor C8 is connected to the No. 1 pin of the resistor R16, the No. 1 pin of the capacitor C7, and the No. 2 pin of the resistor R14. The No. 1 pin of the capacitor C6 and the No. 2 pin of the capacitor C7 are connected to the network NET_0. The No. 1 pin of the resistor R21 and the No. 1 pin of the resistor R14 are connected to the ground network GND_2; the No. 2 negative input terminal pin of the operational amplifier U4 is connected to the No. 2 pin of the resistor R17, and the No. 1 pin of the resistor R17 is connected to the No. 2 pin of the resistor R16 and the No. 1 pin of the resistor R18. Pin 2 of resistor R18 and pin 2 of resistor R19, pin 2 of capacitor C9, and output pin 5 of operational amplifier U4 are all connected to network ADC_GND2. Pin 1 of resistor R19 and pin 1 of capacitor C9 are connected to network NET_0. Pin 3 of operational amplifier U4 is connected to power supply network 5V, and pin 4 of operational amplifier is connected to network NET_0.

[0031] The near-ground voltage NET0 is a very low voltage, and the voltage can usually be set to 0.5V.

[0032] In the specific implementation, the model of the operational amplifier U3 in the GND1 detection module is MCP6V06, the resistor R8 is 2K, the resistor R11 is 2K, the resistor R9 is 500K, the resistor R6 is 300R, the resistor R5 is 300R, the resistor R1 is 300R, the resistor R3 is 300R, the resistor R12 is 5mR, the resistor R10 is 10K, the capacitor C5 is 10nF, the capacitor C4 is 10nF, the capacitor C1 is 10nF, and the capacitor C2 is 10nF.

[0033] The model of the operational amplifier U4 in the GND2 detection module is MCP6V06, the resistor R20 is 2K, the resistor R17 is 2K, the resistor R918 is 500K, the resistor R15 is 300R, the resistor R16 is 300R, the resistor R13 is 300R, the resistor R14 is 300R, the resistor R21 is 5mR, the resistor R19 is 10K, the capacitor C9 is 10nF, the capacitor C6 is 10nF, the capacitor C7 is 10nF, and the capacitor C8 is 10nF.

[0034] In the GND1 detection module, resistor R12 is a current sampling resistor, resistor R11 and resistor R8 are both current limiting resistors; resistor R1 and capacitor C1 form a first-order low-pass filter, resistor R3 and capacitor C2 form a first-order low-pass filter, resistor R9 and operational amplifier U3 form a negative feedback amplifier circuit; resistor R10 is used to stabilize the output potential;

[0035] In the GND2 detection module, resistor R21 is a current sampling resistor, resistor R20 and resistor R17 are both current limiting resistors; resistor R13 and capacitor C6 form a first-order low-pass filter, resistor R14 and capacitor C7 form a first-order low-pass filter, resistor R18 and operational amplifier U4 form a negative feedback amplifier circuit; resistor R19 is used to stabilize the output potential.

[0036] like Figure 1 As shown, the two ground ports GND_1 and GND_2 are connected to the vehicle frame ground via their own ground wires. The two ground wires are routed independently in the vehicle-mounted ECU controller and are point-connected to the vehicle frame ground outside the ECU controller. The vehicle frame ground is connected to the negative pole of the vehicle battery.

[0037] like Figure 1 As shown, the specific implementation also sets the above-mentioned logic return circuit in the ECU controller, and the two grounding ports of the logic return circuit are connected to the metal ground of the metal vehicle frame, and the negative pole of the vehicle battery is also connected to the metal ground of the metal vehicle frame.

[0038] In the solution of the utility model, the whole vehicle frame is made of metal and has a metal ground composed of a copper strip.

[0039] The ECU controller also includes two power return circuits. The grounds of the two power return circuits are used as return current for large current loads such as motors. The ground ends of the two power return circuits are respectively connected to the two ground ports of the logic return circuit and then connected to the metal ground of the metal vehicle frame.

[0040] The two grounding ports of the logic return circuit, the grounding terminals of the two power return circuits and the metal ground of the metal vehicle frame form a grounding network.

[0041] The specific implementation process of the circuit of the utility model is as follows:

[0042] The logic control part (i.e. logic return circuit) of the vehicle-mounted ECU controller consumes about 300mA of current at a voltage of 13.5V. Considering that the difference between the two ground ports GND_1 and GND_2 is small, the current passing through the two ground wires of the two ground ports is 1 / 2 of the total current, i.e. 150mA. The following four cases are explained separately:

[0043] 1. When both ground ports GND_1 and GND_2 are well connected to the vehicle frame ground and ECU controller:

[0044] The currents passing through the sampling resistors R12 and R21 are 150mA respectively. The resistance of the resistor R12 is 50mR, and the voltage drop of the resistor R12 is 0.15A*50mR=0.0075V. Therefore, the voltage of the positive input pin 1 of the operational amplifier U3 is 0.0075V.

[0045] Because the operational amplifier U3 operates under negative feedback conditions, the conditions of virtual short and virtual open circuit of the operational amplifier are met (in operational amplifier theory, the output terminal is connected to the negative pole of the operational amplifier through a resistor to meet the negative feedback conditions). The virtual short circuit causes the voltage of pin 2 of the operational amplifier U3 to be consistent with the voltage of pin 1, so the voltage of pin 2 of the operational amplifier U3 is 0.0075V. The virtual open circuit causes no current to flow into pin 2 of the operational amplifier U3.

[0046] The current I1 passing through resistor R5 = (0.0075V-0V) / (300R+300R) = 1.25*10 -5 A

[0047] The current I2 passing through resistor R9 = (ADC_GND1-0.0075V) / 300K

[0048] Since the currents I1 and I2 are equal in magnitude, the voltage parameters at the first voltage acquisition port ADC_GND1 are obtained:

[0049] 1.25*10^-5A=(ADC_GND1-0.0075V) / 300K

[0050] ADC_GND1 = 3.758V

[0051] Similarly:

[0052] The resistance of resistor R21 is 50mR, and the voltage drop of resistor R21 is also 0.15A*50mR=0.0075V, so the voltage of pin 1 of the positive input terminal of the operational amplifier is 0.0075V.

[0053] Because the operational amplifier U4 operates under negative feedback conditions, the conditions of virtual short and virtual open circuit of the operational amplifier are met. The virtual short causes the voltage of pin 2 of the operational amplifier U4 to be consistent with the voltage of pin 1, so the voltage of pin 2 of the operational amplifier U4 is 0.0075V. The virtual open circuit causes no current to flow into pin 2 of the operational amplifier U4.

[0054] The current I3 passing through resistor R16 = (0.0075V-0V) / (300R+300R) = 1.25*10^-5A

[0055] The current I4 passing through resistor R18 = (ADC_GND2-0.0075V) / 300K

[0056] Since the currents I3 and I4 are equal in magnitude, the voltage parameters at the second voltage acquisition port ADC_GND2 are obtained:

[0057] 1.25*10^-5A=(ADC_GND2-0.0075V) / 300K

[0058] ADC_GND2 =3.758V

[0059] Therefore, when the two ground ports GND_1 and GND_2 are well connected to the vehicle frame ground and the controller, the voltage acquisition port of the ECU controller reads ADC_GND1 = 3.758V, ADC_GND2 = 3.758V.

[0060] 2. When the first ground port GND_1 is well connected and the second ground port GND_2 is disconnected:

[0061] At this time, all the current of the logic control part flows into the GND1 detection module, that is, the resistor R12 of the GND1 detection module. The resistance of resistor R12 is 50mR. At this time, the voltage drop of resistor R12 is: 0.3A*50mR=0.015V, so the voltage of pin 1 of the positive input terminal of the operational amplifier is 0.015V.

[0062] Because the operational amplifier U3 operates under negative feedback conditions, the conditions of virtual short and virtual open circuit of the operational amplifier are met. The virtual short circuit causes the voltage of pin 2 of the operational amplifier U3 to be consistent with the voltage of pin 1. Therefore, the voltage of pin 2 of the operational amplifier U3 is 0.015V. The virtual open circuit causes no current to flow into pin 2 of the operational amplifier U3.

[0063] The current I1 passing through resistor R5 = (0.015V-0V) / (300R+300R) = 2.5*10^-5A

[0064] The current I2 passing through resistor R9 = (ADC_GND1-0.015V) / 300K

[0065] Since the currents I1 and I2 are equal in magnitude, the voltage parameters at the first voltage acquisition port ADC_GND1 are obtained:

[0066] 2.5*10^-5A =(ADC_GND1-0.015V) / 300K

[0067] ADC_GND1=7.515V

[0068] Since the power supply voltage of the operational amplifier U3 is 5V, the maximum output voltage of the operational amplifier is 5V, so the first voltage acquisition port of the ECU controller reads ADC_GND1=5V.

[0069] Because the second ground port GND_2 is disconnected, the voltage of pin 1 of the operational amplifier U4 is consistent with the voltage of pin 2, which is 0.015V. Pin 2 of the operational amplifier U4 is virtually disconnected, that is, no current flows into pin 2, so the currents I3 and I4 are equal. The voltage of pin 1 of the resistor R17 is 0.015V, and the potential at the second ground port GND_2 is 0.015V.

[0070] The current I3 passing through resistor R16 = (0.015V- GND_2) / (300R+300R) = 0A

[0071] The current I4 passing through resistor R18 = (ADC_GND2-0.015V) / 300K

[0072] Since the currents I3 and I4 are equal in magnitude, the voltage parameters at the second voltage acquisition port ADC_GND2 are obtained:

[0073] 0A = (ADC_GND2-0.015V) / 300K

[0074] ADC_GND2=0.015V

[0075] Therefore, when GND_1 is well connected and GND_2 is disconnected, the controller voltage acquisition port reads ADC_GND1 = 5V and ADC_GND2 = 0.015V.

[0076] 3. When the first ground port GND_1 is disconnected and the second ground port GND_2 is well connected:

[0077] At this time, all the current of the logic control part flows into the GND2 detection module, that is, the resistor R21 of the GND2 detection module. The resistance value of the resistor R21 is 50mR. At this time, the voltage drop of the resistor R21 is: 0.3A*50mR=0.015V, so the voltage of the positive input pin 1 of the operational amplifier is 0.015V.

[0078] Because the operational amplifier U4 works under negative feedback conditions, the conditions of virtual short and virtual disconnection of the operational amplifier are met. Virtual short causes the voltage of pin 2 of the operational amplifier U4 to be consistent with the voltage of pin 1, so the voltage of pin 2 of the operational amplifier U4 is 0.015V, and virtual disconnection causes no current to flow into pin 2 of the operational amplifier U4.

[0079] The current I3 passing through resistor R16 = (0.015V-0V) / (300R+300R) = 2.5*10^-5A

[0080] The current I4 passing through resistor R18 = (ADC_GND2-0.015V) / 300K

[0081] Since the currents I3 and I4 are equal in magnitude, the voltage parameters at the second voltage acquisition port ADC_GND2 are obtained:

[0082] 2.5*10^-5A =(ADC_GND2-0.015V) / 300K

[0083] ADC_GND2=7.515V

[0084] Since the power supply voltage of the operational amplifier is 5V, the maximum output voltage of the operational amplifier is 5V, so the second voltage acquisition port of the ECU controller reads ADC_GND2=5V.

[0085] Because the first ground port GND_1 is disconnected, the voltage of pin 1 of the operational amplifier U3 is consistent with the voltage of pin 2, which is 0.015V. Pin 2 of the operational amplifier U3 is virtually disconnected, that is, no current flows into pin 2, so the currents I1 and I2 are equal. The voltage of pin 2 of the resistor R11 is 0.015V, and the potential at the first ground port GND_1 is 0.015V.

[0086] The current I1 passing through resistor R5 = (0.015V- GND_1) / (300R+300R) = 0A

[0087] The current I2 passing through resistor R9 = (ADC_GND1-0.015V) / 300K

[0088] Since the currents I1 and I2 are equal in magnitude, the voltage parameters at the first voltage acquisition port ADC_GND1 are obtained:

[0089] 0A = (ADC_GND1-0.015V) / 300K

[0090] ADC_GND1=0.015V

[0091] Therefore, when GND_1 is disconnected and GND_2 is well connected, the first voltage acquisition port of the ECU controller reads ADC_GND1 = 0.015V, ADC_GND2 = 5V

[0092] 4. When both ground ports GND_1 and GND_2 are disconnected:

[0093] At this time, the ground return loop of the logic circuit is completely disconnected.

[0094] Then the voltage acquisition port of the ECU controller reads ADC_GND1=0V, ADC_GND2=0V

[0095] Therefore, the voltage value is read through the voltage acquisition port of the ECU controller to determine the state and result of the open circuit of the vehicle controller.

[0096] In a specific implementation, the offset refers to the impact on the system caused by the ground potential being raised to +1V or lowered to -1V, which can also be detected by the above circuit.

Claims

1. A circuit for detecting ground open circuit and voltage offset of a vehicle controller, characterized in that: The circuit is a logic reflux circuit, which includes two parts: a GND1 detection module and a GND2 detection module. After the GND1 detection module and the GND2 detection module are connected, they are close to the ground voltage NET0. At the same time, the GND1 detection module and the GND2 detection module each lead out a grounding port connected to the ground of the vehicle frame.

2. A circuit for detecting ground open circuit and voltage offset of a vehicle controller according to claim 1, characterized in that: The GND1 detection module includes an operational amplifier U3 and multiple resistors and multiple capacitors. Resistors R1, R12 and R3 are connected in series and then connected in parallel to the two ends of capacitor C4. Capacitors C1 and C2 are connected in series and then connected in parallel to the two ends of capacitor C4. One end of capacitor C4 is connected to the negative input end of operational amplifier U3 through resistors R5 and R11. The other end of capacitor C4 is connected to the positive input end of operational amplifier U3 through resistors R6 and R8. The end between resistors R5 and R11 is connected to the positive input end of operational amplifier U3 through resistor R9. 3, the output end of the operational amplifier U3 is connected to the external first voltage acquisition port ADC_GND1; the end led between the resistor R12 and the resistor R3, the end led between the capacitor C1 and the capacitor C2, and the negative power supply terminal of the operational amplifier U3 are all connected to the near-ground voltage NET0, the positive power supply terminal of the operational amplifier U3 is connected to the power supply voltage, the output end of the operational amplifier U3 is connected to the near-ground voltage NET0 after passing through the resistor R10 and the capacitor C5, and the end led between the resistor R1 and the resistor R12 is used as the first ground port GND_1; The GND2 detection module includes an operational amplifier U4 and multiple resistors and multiple capacitors. Resistors R14, R21 and R13 are connected in series and connected in parallel to both ends of capacitor C8. Capacitors C6 and C7 are connected in series and connected in parallel to both ends of capacitor C8. One end of capacitor C8 is connected to the negative input end of operational amplifier U4 through resistors R15 and R20. The other end of capacitor C8 is connected to the positive input end of operational amplifier U4 through resistors R16 and R17. The end between resistors R16 and R17 is connected to the positive input end of operational amplifier U4 through resistor R18. The output end of the operational amplifier U4 is connected to the external second voltage acquisition port ADC_GND2; the end led out between the resistor R21 and the resistor R13, the end led out between the capacitor C6 and the capacitor C7, and the negative power supply terminal of the operational amplifier U4 are all connected to the near-ground voltage NET0, the positive power supply terminal of the operational amplifier U3 is connected to the power supply voltage, the output end of the operational amplifier U4 is connected to the near-ground voltage NET0 after passing through the resistor R19 and the capacitor C9, and the end led out between the resistor R21 and the resistor R14 serves as the second ground port GND_2.

3. A circuit for detecting ground open circuit and voltage offset of a vehicle controller according to claim 1, characterized in that: The near-ground voltage NET0 is a very low voltage.

4. A circuit for detecting ground open circuit and voltage offset of a vehicle controller according to claim 1, characterized in that: In the GND1 detection module, resistor R12 is a current sampling resistor, resistor R11 and resistor R8 are both current limiting resistors; resistor R1 and capacitor C1 form a first-order low-pass filter, resistor R3 and capacitor C2 form a first-order low-pass filter, resistor R9 and operational amplifier U3 form a negative feedback amplifier circuit; resistor R10 is used to stabilize the output potential; In the GND2 detection module, resistor R21 is a current sampling resistor, resistor R20 and resistor R17 are both current limiting resistors; resistor R13 and capacitor C6 form a first-order low-pass filter, resistor R14 and capacitor C7 form a first-order low-pass filter, resistor R18 and operational amplifier U4 form a negative feedback amplifier circuit; resistor R19 is used to stabilize the output potential.

5. A circuit for detecting ground open circuit and voltage offset of a vehicle controller according to claim 1, characterized in that: The two ground ports GND_1 and GND_2 are connected to the vehicle frame ground through their own ground wires. The two ground wires are routed independently in the vehicle-mounted ECU controller and are point-connected to the vehicle frame ground outside the ECU controller. The vehicle frame ground is connected to the negative pole of the vehicle battery.

6. An in-vehicle arrangement mechanism, characterized in that: A circuit for detecting open ground circuit and voltage offset of a vehicle-mounted controller as described in any one of claims 1-5 is arranged in an ECU controller, and both ground ports of the logic return circuit are connected to the ground of the metal vehicle frame, and the negative pole of the vehicle-mounted battery is also connected to the ground of the metal vehicle frame.

7. The in-vehicle arrangement mechanism according to claim 6, characterized in that: The ECU controller also includes two power return circuits, and the grounding ends of the two power return circuits are respectively connected to the two grounding ports of the logic return circuit and then connected to the ground of the metal vehicle frame.

8. The in-vehicle arrangement mechanism according to claim 6, characterized in that: The two grounding ports of the logic return circuit, the grounding terminals of the two power return circuits and the ground of the metal vehicle frame form a grounding network.

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