A detection system and vehicle

Abstract

The application provides a detection system and a vehicle, and relates to the technical field of voltage detection. The detection system comprises a switching circuit, a first sampling circuit, a second sampling circuit and a controller. The first end of the switching circuit is connected with a low-voltage power supply, and the second end of the switching circuit is connected with a reference voltage. The first sampling circuit is connected with the third end of the switching circuit, and the first sampling circuit outputs a first sampling signal. The second sampling circuit is connected with the third end of the switching circuit and the first sampling circuit, and the second sampling circuit outputs a second sampling signal. The controller is connected with the first sampling circuit, the second sampling circuit and the controlled end of the switching circuit. The controller receives the first sampling signal and the second sampling signal, and controls the conduction state of the switching circuit based on the first sampling signal and the second sampling signal. When an abnormality is detected, the system can accurately identify whether the low-voltage power supply fails or the sampling circuit fails by controlling the conduction state of the switching circuit, reduce the false positive rate, prompt the availability of the system, and ensure the detection reliability of the detection system.

Description

Technical Field

[0001] This application relates to the field of voltage detection technology, and more specifically, to a detection system and vehicle. Background Technology

[0002] In new energy vehicles, low-voltage power supplies are used to power key components such as the Body Control Module (BCM), lighting system, and Engine Control Unit (ECU). The voltage stability of the low-voltage power supply directly affects the safety and functional reliability of the entire vehicle.

[0003] Currently, voltage detection circuits are typically included to monitor the output voltage of low-voltage power supplies. However, damage to the electronic components in these circuits can affect the detection results. Related technologies often cannot accurately distinguish between a low-voltage power supply fault and a voltage detection circuit fault, potentially leading to detection errors. For example, if the low-voltage power supply is normal but the voltage detection circuit malfunctions, the detected voltage value may be false (too high or too low), potentially triggering unnecessary protection actions (such as power outages, alarms, or shutdowns), thus affecting the normal operation of the vehicle. Utility Model Content

[0004] This application provides a detection system and vehicle, which aims to solve the problem in related technologies that cannot accurately identify whether the fault is a low-voltage power supply fault or a sampling circuit fault, which may lead to detection errors, such as false voltage values, triggering unnecessary protection actions, and affecting the normal use of the vehicle.

[0005] In a first aspect, a detection system is provided, comprising a switching circuit, a first sampling circuit, a second sampling circuit, and a controller; a first terminal of the switching circuit is connected to a low-voltage power supply, and a second terminal of the switching circuit is connected to a reference voltage; the first sampling circuit is connected to a third terminal of the switching circuit and is used to output a first sampling signal; the second sampling circuit is connected to the third terminal of the switching circuit and the first sampling circuit and is used to output a second sampling signal; the controller is connected to the controlled terminal of the first sampling circuit, the second sampling circuit, and the switching circuit, and receives the first sampling signal and the second sampling signal, and controls the conduction state of the switching circuit based on the first sampling signal and the second sampling signal; wherein, the conduction state of the switching circuit includes a first conduction state and a second conduction state, in which the first terminal of the switching circuit is connected to the third terminal of the switching circuit, and in the second conduction state, the second terminal of the switching circuit is connected to the third terminal of the switching circuit.

[0006] In the above technical solution, when the controller determines that there is no abnormality based on the first and second sampling signals, the switching circuit is in the first conducting state. At this time, the controller performs real-time detection of the low-voltage power supply voltage based on the first and second sampling signals to achieve detection of the low-voltage power supply; the detection system then performs the detection function. When the controller determines that there is an abnormality based on the first and second sampling signals, the controller controls the switching circuit to the second conducting state. At this time, the first and second sampling circuits generate the first and second detection signals based on the reference voltage. The controller can determine whether there is a fault in the sampling circuit based on the first and second detection signals; the detection system then performs the fault location function. If the detection signals determine that there is no abnormality in either sampling circuit, it indicates that there is an abnormality in the low-voltage power supply. In this case, the system triggers a protection action to prevent the low-voltage power supply abnormality from affecting the normal use of the vehicle. If the detection signals determine that one of the sampling circuits is abnormal, the controller determines whether there is an abnormality in the low-voltage power supply based on the sampling signal output by the other sampling circuit that is not abnormal, to ensure the continuity of low-voltage power supply detection and avoid detection interruption. If the detection signal indicates that both sampling circuits are faulty, the detection system cannot continue detecting the low-voltage power supply and must report the issue for repair. Therefore, this application, by controlling the conduction state of the switching circuit, can detect the low-voltage power supply and accurately identify whether the fault is in the low-voltage power supply or the sampling circuit when an anomaly is detected. This avoids false voltage readings caused by sampling circuit faults, which could trigger unnecessary protection actions (such as power outages or alarms) and affect the normal operation of the vehicle. This improves system availability, reduces the false alarm rate, and ensures the detection reliability of the system and the reliability of the vehicle.

[0007] In conjunction with the first aspect, in some possible implementations, the switching circuit includes a voltage source and a switching module; the voltage source is connected to a low-voltage power supply and is used to output a reference voltage; the first terminal of the switching module is connected to the low-voltage power supply as the first terminal of the switching circuit, the second terminal of the switching module is connected to the voltage source as the second terminal of the switching circuit, the third terminal of the switching module is connected to the first sampling circuit and the second sampling circuit as the third terminal of the switching circuit, and the controlled terminal of the switching module is connected to the controller as the controlled terminal of the switching circuit.

[0008] In the above technical solution, the conduction state of the switching circuit can be switched by changing the conduction state of the switching module, which provides high switching flexibility. Furthermore, a voltage source is provided to offer a stable reference voltage to the detection system, thereby ensuring the reliability of subsequent fault detection and location of the sampling circuit based on this reference voltage.

[0009] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the switching module includes a relay, the relay includes a coil and a single-pole double-throw switch; one end of the coil is connected to a low-voltage power supply, and the other end of the coil serves as the controlled end of the switching module and is connected to the controller; the common end of the single-pole double-throw switch serves as the third end of the switching module and is connected to the first sampling circuit and the second sampling circuit; the first switching end of the single-pole double-throw switch serves as the first end of the switching module and is connected to the low-voltage power supply; and the second switching end of the single-pole double-throw switch serves as the second end of the switching module and is connected to the voltage source.

[0010] In the above technical solution, the overall conduction state of the switching circuit can be switched by changing the energized state of the coil, providing high switching flexibility. Secondly, the coil in the relay and the single-pole double-throw switch are physically isolated, with no direct electrical connection, which effectively prevents noise interference, improves the anti-interference capability of the switching circuit, and enhances the overall safety and reliability of the system.

[0011] In combination with the first aspect and the above implementation, in some possible implementations, the controller is used to generate an error signal based on the first sampling signal and the second sampling signal, and when the error signal is greater than or equal to the error threshold, the controller controls the switching circuit to be in the second conduction state.

[0012] In the above technical solution, the controller calculates an error signal based on the actual voltage value. When the error signal is greater than or equal to the error threshold, it indicates that an anomaly exists in the detection system. The controller then controls the switching circuit to a second conduction state, enabling the controller to locate the specific fault point. Thus, this application can determine the presence of an anomaly through the error signal, providing reliable support for subsequent fault location.

[0013] In conjunction with the first aspect and the above implementation, in some possible implementations, the controller is further configured to generate a first voltage value based on the first sampling signal and a second voltage value based on the second sampling signal, and select one of the first sampling circuit and the second sampling circuit as the main sampling circuit and the other as the sub-sampling circuit based on the first voltage value, the second voltage value and the reference voltage.

[0014] In the above technical solution, the controller can determine the "true" sampling circuit and the "false" sampling circuit based on the first voltage value, the second voltage value, and the reference voltage. Based on the detection results, it selects the "true" sampling circuit as the main sampling circuit and the "false" sampling circuit as the secondary sampling circuit. This avoids the possibility of back-and-forth switching between the main and secondary sampling circuits, which could lead to frequent fault protection strategies and false alarms, thus improving detection reliability. Secondly, this application can switch to the correct sampling circuit for voltage sampling, achieving the purpose of non-stop detection.

[0015] In combination with the first aspect and the above implementation methods, in some possible implementation methods, both the first sampling circuit and the second sampling circuit include an anti-interference module, a temperature drift compensation module, and an amplification module; the anti-interference module and the temperature drift compensation module are connected in series between the third terminal of the switching circuit and the input terminal of the amplification module, and the output terminal of the amplification module is connected to the controller for outputting the first sampling signal.

[0016] In the above technical solution, the temperature drift compensation module, the anti-interference module, and the amplification module work together to form a voltage detection front-end processing system. This ensures that the detection circuit can accurately and reliably transmit the low-voltage power supply output voltage information to the controller under various complex working conditions, thereby improving the detection accuracy of the low-voltage power supply output voltage and providing a reliable guarantee for the continuous acquisition of low-voltage power supply output voltage information by the vehicle controller or battery management system.

[0017] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the first sampling circuit and the second sampling circuit further include a filtering module, which is connected in series between the output of the amplification module and the controller.

[0018] In the above technical solution, the voltage signal amplified by the amplification module is further filtered by the filtering module to make the signal transmitted to the controller purer, thereby further improving the accuracy of voltage detection. Furthermore, the filtering module can smooth the signal, reducing signal fluctuations and jitter, thus making the voltage signal transmitted to the controller more stable. This allows the controller to sample and process the voltage signal more accurately, thereby improving the reliability and accuracy of the entire voltage detection system.

[0019] Combining the first aspect and the above implementation methods, in some possible implementation methods, the anti-interference module includes a common-mode inductor, a filter unit, and an overvoltage protection unit; the positive input terminal of the common-mode inductor is connected to the third terminal of the switching circuit, and the negative input terminal of the common-mode inductor is connected to the negative terminal of the low-voltage power supply; the input terminal of the filter unit is connected to both the positive and negative output terminals of the common-mode inductor; the input terminal of the overvoltage protection unit is connected to the output terminal of the filter unit, and the output terminal of the overvoltage protection unit is connected to the input terminal of the amplification module.

[0020] In the above technical solution, a hybrid anti-interference module is formed by combining a common-mode inductor, a filtering unit, and an overvoltage protection unit. This improves the sampling circuit's ability to resist various interferences and abnormal voltage conditions, thereby enhancing the overall anti-interference performance of the detection circuit and providing a reliable guarantee for the vehicle controller or battery management system to continuously acquire information on the low-voltage power supply output voltage.

[0021] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the overvoltage protection unit includes a transient voltage suppression diode. The first terminal of the transient voltage suppression diode is connected to the output terminal of the filter unit and the input terminal of the amplification module, and the second terminal of the transient voltage suppression diode is connected to the negative output terminal of the common-mode inductor and the input terminal of the amplification module.

[0022] In the above technical solution, the transient voltage suppressor diode can prevent large voltages from entering the amplification module from the positive and negative terminals of the low-voltage power supply, thereby protecting the amplification module, reducing the probability of damage to the amplification module, and enabling the amplification module to have a longer service life.

[0023] Secondly, embodiments of this application also provide a vehicle, the vehicle including a body, a low-voltage power supply, and a detection system as described in any of the optional embodiments of the first aspect, wherein the low-voltage power supply is disposed within the body; the detection system is disposed within the body and connected to the output terminal of the low-voltage power supply. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application; Figure 2 This is a schematic diagram of a detection system provided in an embodiment of this application; Figure 3 This is a schematic diagram illustrating the relationship between a sampling signal and time, provided in an embodiment of this application. Figure 4 This is a schematic diagram of another detection system provided in an embodiment of this application; Figure 5 This is a circuit diagram of a detection system provided in an embodiment of this application.

[0025] In the attached figures, the following labels are used: 1. Vehicle body; 2. Power supply; 3. Detection system; 31. First sampling circuit; 311. Anti-interference module; 3111. Filtering unit; 3112. Overvoltage protection unit; 312. Temperature drift compensation module; 313. Amplification module; 314. Filtering module; 32. Second sampling circuit; 321. Anti-interference module; 322. Temperature drift compensation module; 323. Amplification module; 324. Second filtering module; 33. Controller; 34. Switching circuit; 341. Switching module; U, voltage source; KY1, control signal; L0, coil; L1, first coil; L2, second coil; SPDT, single-pole double-throw switch; R1, first resistor; R2, second resistor; R3, third resistor; C1, first capacitor; C2, second capacitor; D1, transient voltage suppressor diode; NTC, thermistor; U1, operational amplifier. Detailed Implementation

[0026] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0027] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0028] In new energy vehicles, a 12V low-voltage power supply is used to power key components such as the Body Control Module (BCM), lighting system, Engine Control Unit (ECU), controller, sensors, and communication module. The voltage stability of the low-voltage power supply directly affects the safety and functional reliability of the entire vehicle.

[0029] Currently, voltage detection circuits are typically installed to monitor the output voltage of low-voltage power supplies. However, during use, the electronic components within these circuits may fail. Damage to these components can affect the detection results and even damage the entire circuit. Furthermore, current technologies cannot accurately distinguish between a low-voltage power supply fault and a faulty voltage detection circuit, potentially leading to incorrect detection. For example, assuming the low-voltage power supply is normal but the voltage detection circuit malfunctions, the detected voltage value may be too high or too low. In this case, the detected abnormal voltage value does not necessarily indicate a low-voltage power supply malfunction, but the system will still determine this as a fault, triggering unnecessary protective actions (such as power outages, alarms, or shutdowns), affecting the normal operation of the vehicle. Conversely, if the voltage detection circuit itself is faulty, current technologies cannot determine the cause of the failure in the circuit's faulty link, such as an open circuit or short circuit in the voltage divider resistor. In other words, current technologies cannot accurately pinpoint the fault location within the voltage detection circuit.

[0030] This application provides a detection system and a vehicle. When an anomaly is detected, the system can accurately identify whether it is a low-voltage power supply fault or a sampling circuit fault by controlling the conduction state of the switching circuit, thereby reducing the false alarm rate, indicating the availability of the system, and ensuring the detection reliability of the detection system.

[0031] The detection system and vehicle provided in the embodiments of this application will be described exemplarily below with reference to the accompanying drawings.

[0032] This application provides a vehicle, such as... Figure 1 As shown, the vehicle includes a body 1, a low-voltage power supply 2, and a detection system 3. The low-voltage power supply 2 is located within the body 1 and typically includes a 12V low-voltage power supply. This low-voltage power supply powers the onboard low-voltage electrical equipment and the vehicle control system. For example, the onboard low-voltage electrical equipment includes basic electronic devices (such as the vehicle's instrument panel, lighting system (headlights, turn signals, brake lights), windshield wipers, window regulators, and central locking), onboard entertainment and information systems (such as car audio systems, navigation systems, onboard displays, and onboard communication modules (such as vehicle networking terminals), etc.), and sensor and control systems (such as controllers for various sensors in vehicle 1 (such as tire pressure monitoring sensors, reversing radar sensors, and ambient temperature sensors) and electronic control systems (such as the Electronic Stability Program (ESP) and Electronic Power Steering (EPS)). The vehicle control system includes a vehicle controller (VCU), a battery management system (BMS), and a motor control unit (MCU).

[0033] Of course, in other embodiments, such as when a new energy vehicle is started, the low-voltage power supply 2 can also supply power to the control circuits of high-voltage system components such as high-voltage contactors and DC-DC converters, so that the high-voltage system can be smoothly connected and started, providing energy to drive motors and other high-voltage loads (such as air conditioning compressors and electric heaters).

[0034] The detection system 3 is installed inside the vehicle body 1 and connected to the output terminal of the low-voltage power supply 2. It is used to detect the output voltage of the low-voltage power supply 2 to ensure that the output voltage of the low-voltage power supply 2 can be maintained within the normal operating range. If the voltage is too high or too low, the protection mechanism can be triggered in time to reduce the probability of abnormal operation or damage to the vehicle electrical appliances caused by the output voltage fluctuation of the low-voltage power supply 2, thereby enabling the vehicle electrical appliances to have a longer service life.

[0035] Furthermore, it can transmit the detected voltage signal to the vehicle controller or battery management system so that when the detected voltage of the detection system 3 is lower than the preset voltage value, the vehicle controller or battery management system can control the high-voltage system to charge the low-voltage power supply 2.

[0036] In related technologies, when a single detection circuit is used for detection, there is no redundancy or fault tolerance. This means that if the detection circuit overloads or short-circuits, the detection system cannot function properly and may even shut down the entire system, resulting in low reliability. Therefore, in one example, such as... Figure 2 As shown, the detection system 3 provided in this application includes a first sampling circuit 31, a second sampling circuit 32, and a controller 33. The first sampling circuit 31 and the second sampling circuit 32 are respectively connected to the low-voltage power supply 2 (i.e., 12V in the figure) and the controller 33.

[0037] In this example, the first sampling circuit 31 outputs a first sampling signal IN1 to the controller 33 based on the low-voltage power supply 2, and the second sampling circuit 32 outputs a second sampling signal IN2 to the controller 33 based on the low-voltage power supply 2. The controller 33 can determine the voltage of the low-voltage power supply 2 based on the first sampling signal IN1 and the second sampling signal IN2. Specifically, the controller 33 can convert the first sampling signal IN1 and the second sampling signal IN2 into actual voltage values ​​using a proportional algorithm to determine the voltage of the low-voltage power supply 2 accordingly.

[0038] It is understandable that the first sampling circuit 31 and the second sampling circuit 32 are respectively a main sampling circuit and a sub-sampling circuit, with the first sampling circuit 31 designated as the main sampling circuit and the second sampling circuit 32 as the sub-sampling circuit. During the detection process, the controller 33 receives two sampling signals from the main sampling circuit and the sub-sampling circuit in real time. Under normal circumstances, i.e., when the main sampling circuit is not faulty, the controller 33 will only determine the voltage of the low-voltage power supply 2 based on the first sampling signal IN1 output by the main sampling circuit. At this time, the second sampling signal IN2 output by the sub-sampling circuit is only used for monitoring. When the main sampling circuit is faulty, the controller 33 can automatically switch to the sub-sampling circuit to ensure the continuity and reliability of the detection. Similarly, when the first sampling circuit 31 is designated as the sub-sampling circuit and the second sampling circuit 32 as the main sampling circuit, the specific detection logic can be referred to the detection logic described above, and will not be repeated here.

[0039] Thus, the first sampling circuit 31 and the second sampling circuit 32 employ a redundancy mechanism, with one sampling circuit designated as the primary sampling circuit and the other as the secondary sampling circuit. Under normal circumstances, the controller 33 can detect the voltage of the low-voltage power supply 2 based on the sampling signal provided by the primary sampling circuit. When the primary sampling circuit fails, the controller 33 can automatically switch to the secondary sampling circuit. That is, the controller 33 can then detect the voltage of the low-voltage power supply 2 based on the sampling signal provided by the secondary sampling circuit. This allows the detection system 3 to continue operating and detecting even when a partial fault occurs, avoiding the problem of the entire system crashing and shutting down due to a sampling circuit failure, thereby ensuring the continuity and reliability of the detection system 3.

[0040] Furthermore, when the controller 33 determines an anomaly based on the first sampling signal IN1 and the second sampling signal IN2, the anomaly could be a fault in the low-voltage power supply 2 or a fault in the sampling circuit itself. To enable the controller 33 provided in this application to accurately identify whether the fault is in the low-voltage power supply or the sampling circuit, in one example, such as... Figure 2 As shown, the detection system 3 provided in this application also includes a switching circuit 34. The first terminal of the switching circuit 34 is connected to the low-voltage power supply 2, and the second terminal of the switching circuit 34 is connected to the reference voltage V0. The first sampling circuit 31 is connected to the third terminal of the switching circuit 34, the second sampling circuit 32 is connected to the third terminal of the switching circuit 34 and the first sampling circuit 31, and the controller 33 is connected to the controlled terminals of the first sampling circuit 31, the second sampling circuit 32 and the switching circuit 34.

[0041] In this example, the controller 33 receives a first sampling signal IN1 and a second sampling signal IN2, and determines the voltage of the low-voltage power supply 2 based on the first sampling signal IN1 and the second sampling signal IN2. Simultaneously, the controller 33 also controls the conduction state of the switching circuit 34 based on the first sampling signal IN1 and the second sampling signal IN2. The controller 33 can output a control signal KY1 to the switching circuit 34 to control the switching circuit 34 to be in different conduction states.

[0042] The switching circuit 34 has two conduction states: a first conduction state and a second conduction state. In the first conduction state, the first terminal of the switching circuit 34 is connected to the third terminal of the switching circuit 34. At this time, the switching circuit 34 is connected to the low-voltage power supply 2. Correspondingly, the voltage connected to the first sampling circuit 31 and the second sampling circuit 32 is the voltage provided by the low-voltage power supply 2, meaning that the detection system is in voltage detection function. In the second conduction state, the second terminal of the switching circuit 34 is connected to the third terminal of the switching circuit 34. At this time, the switching circuit 34 is connected to the reference voltage V0. Correspondingly, the voltage connected to the first sampling circuit 31 and the second sampling circuit 32 is the reference voltage V0, meaning that the detection system is in fault location function.

[0043] For example, when the controller 33 determines that there is no abnormality based on the first sampling signal IN1 and the second sampling signal IN2, the controller 33 controls the switching circuit 34 to remain in the first conducting state. At this time, the signals output by the first sampling circuit 31 and the second sampling circuit 32 are the first sampling signal IN1 and the second sampling signal IN2 generated based on the 12V voltage. The controller 33 continuously detects the output voltage of the low-voltage power supply 2 based on the first sampling signal IN1 and the second sampling signal IN2.

[0044] For example, when the controller 33 determines an anomaly based on the first sampling signal IN1 and the second sampling signal IN2, in order to determine whether the anomaly is in the low-voltage power supply 2 or the sampling circuit, the controller 33 will control the switching circuit 34 to a second conducting state. When the switching circuit 34 is in the second conducting state, the signals output by the first sampling circuit 31 and the second sampling circuit 32 are a first detection signal and a second detection signal generated based on the reference voltage V0. The controller 33 can determine whether there is a fault in the sampling circuit based on the first detection signal and the second detection signal.

[0045] Understandably, when the switching circuit 34 is in the second conducting state, if both the first sampling circuit 31 and the second sampling circuit 32 are normal, the first and second detection signals output to the controller 33 will be the same as the actual voltage value corresponding to the reference voltage V0. Alternatively, the detection signals will be the same as the preset voltage threshold in the controller 33. Based on the first and second detection signals at this time, the controller 33 determines that there is no abnormality in the sampling circuit, and thus determines that the low-voltage power supply 2 is abnormal. At this time, the system triggers a protection action to prevent the low-voltage power supply 2 abnormality from affecting the normal use of the vehicle.

[0046] If either the first sampling circuit 31 or the second sampling circuit 32 malfunctions, the detection signal output to the controller 33 will differ from the actual voltage value corresponding to the reference voltage V0. For example, the detection signal may be 0, or there may be a voltage deviation between the detection signal and the reference voltage V0, or the detection signal may differ from the preset voltage threshold in the controller 33. The controller 33 determines that the corresponding sampling circuit is malfunctioning based on this detection signal. Simultaneously, the controller 33 will determine whether the low-voltage power supply 2 is malfunctioning based on the sampling signal output from the other sampling circuit, ensuring detection continuity and avoiding detection interruptions. Therefore, when the switching circuit 34 is in the second conducting state, the controller 33 can determine whether the low-voltage power supply 2 or the sampling circuit is malfunctioning based on the first and second detection signals. If the sampling circuit is malfunctioning, the controller 33 can pinpoint the specific sampling circuit malfunctioning. In this case, the controller 33 determines that the malfunction is in the sampling circuit, not the low-voltage power supply 2, based on the first sampling signal IN1 and the second sampling signal IN2. At this point, maintenance can be performed on the sampling circuit without stopping the machine. This avoids the problem in related technologies where it is impossible to accurately identify whether the fault is in the low-voltage power supply 2 or the sampling circuit, which can cause false voltage alarms, trigger unnecessary protection actions, and affect the normal use of the entire vehicle.

[0047] In this example, after determining that a faulty sampling circuit exists based on the first and second detection signals, the controller 33 can also locate the specific fault point in the faulty sampling circuit based on the reference voltage V0. Specifically, the controller 33 has preset voltage thresholds for each device in the sampling circuit under normal conditions. When an abnormality occurs in the sampling circuit, the voltage of the corresponding abnormal device in the sampling circuit will also deviate. The controller 33 compares the voltage corresponding to the detected signal at this time with the voltage threshold to determine the device with the deviation, thereby achieving accurate location of the fault point in the abnormal sampling circuit.

[0048] In summary, when the controller 33 determines that there is no abnormality based on the first sampling signal IN1 and the second sampling signal IN2, the switching circuit 34 is in the first conducting state. At this time, the controller 33 performs real-time detection of the voltage of the low-voltage power supply 2 based on the first sampling signal IN1 and the second sampling signal IN2 to achieve detection of the low-voltage power supply 2. At this time, the detection system performs the voltage detection function. When the controller 33 determines that there is an abnormality based on the first sampling signal IN1 and the second sampling signal IN2, the controller 33 will control the switching circuit 34 to be in the second conducting state. At this time, the first sampling circuit 31 and the second sampling circuit 32 will generate the first detection signal and the second detection signal based on the reference voltage V0. The controller 33 can determine whether there is a fault in the sampling circuit based on the first detection signal and the second detection signal. At this time, the detection system performs the fault location function. If it is determined that there is no abnormality in the sampling circuit based on the detection signals, it means that there is an abnormality in the low-voltage power supply 2. At this time, the system triggers protection actions (such as power failure, alarm, etc.) to prevent the abnormality of the low-voltage power supply 2 from affecting the normal use of the vehicle. If the detection signal indicates an abnormality in one of the sampling circuits, the controller 33 determines whether the low-voltage power supply 2 is also abnormal based on the sampling signal output from the other sampling circuit that is not abnormal. This ensures the continuity of the detection of the low-voltage power supply 2 and avoids detection interruption. If the detection signal indicates that both sampling circuits are abnormal, the detection system cannot continue to detect the low-voltage power supply 2 and must report the issue for repair. Thus, by controlling the conduction state of the switching circuit 34, this application can detect the low-voltage power supply 2 and accurately identify whether the abnormality is due to a fault in the low-voltage power supply 2 or a fault in the sampling circuit. This avoids false voltage alarms caused by sampling circuit faults, which could trigger unnecessary protection actions (such as power outages or alarms) and affect the normal operation of the vehicle. This improves system availability to 100%, reduces the false alarm rate to >96%, and ensures the detection reliability of the system and the reliability of the vehicle.

[0049] To enable the controller 33 to determine the presence of an anomaly based on the first sampling signal IN1 and the second sampling signal IN2, in one example, the controller 33 generates an error signal based on the first sampling signal IN1 and the second sampling signal IN2. When the error signal is greater than or equal to an error threshold, the controller controls the switching circuit 34 to be in a second conduction state. It is worth noting that after receiving the first sampling signal IN1, the controller 33 converts the first sampling signal IN1 into the corresponding actual voltage value Vol13 according to a preset proportional algorithm (voltage divider algorithm and digital-to-analog conversion). Simultaneously, it adds a voltage offset EFF1 to calculate the true voltage value Vol12, which is the actual voltage of the low-voltage power supply 2 sampled by the first sampling circuit 31 at this time. Similarly, after receiving the second sampling signal IN2, the controller 33 also converts it into the corresponding actual voltage value Vol23, adds a voltage offset EFF2, and calculates the true voltage value Vol22.

[0050] The controller 33 has a preset error threshold, for example, such as Figure 3 As shown, the error threshold is set to ±0.5V. Figure 3 The horizontal axis represents the sampling time, and the vertical axis represents the voltage value. Vin1 is the first sampled signal IN1, and Vin2 is the second sampled signal IN2. When the error signal calculated by the controller 33 is greater than or equal to the error threshold (i.e., ≥ ±0.5V), it indicates that a fault exists in the detection system 3. At this time, the difference threshold mechanism is triggered, and the controller 33 controls the switching circuit 34 to be in the second conduction state. For example, Figure 3 During the time periods t5~t9 and t11~t17, the difference threshold triggering mechanism is met, and the system enters the "cross-validation + fault diagnosis mechanism" stage, that is, the control switching circuit 34 is in the second conduction state and the fault code is recorded. Figure 3 The sampling strategy is satisfied in both the time periods t10~t11 and t17~t18.

[0051] It is worth noting that the sampling strategy provided in this application can adopt a dynamic sampling strategy. For example, the controller 33 can obtain the first sampling signal IN1 and the first sampling signal IN2 at a first sampling frequency and through a smoothing filtering algorithm. This represents the steady-state mode of the output voltage of the low-voltage power supply 2. For example, the first sampling frequency can be 1kHz. In other embodiments, the first sampling frequency can also be 2kHz, 3kHz, 4kHz, 5kHz, etc. In this application embodiment, the specific value of the first sampling frequency is not limited.

[0052] For example, if the voltage change rate of at least one of the first sampling signal IN1 and the second sampling signal IN2 is greater than a preset change rate (e.g., 2V / ms), it indicates that the output voltage of the low-voltage power supply 2 has entered a transient mode (e.g., when the vehicle accelerates rapidly, that is, the output voltage of the low-voltage power supply 2 changes rapidly). At this time, the controller 33 switches to the second sampling frequency and obtains the first sampling signal IN1 and the second sampling signal IN2 through the Kalman algorithm to improve the sampling speed of the controller 33. Furthermore, through a more advanced algorithm, the efficiency of obtaining the first sampling signal IN1 and the second sampling signal IN2 is improved, thereby shortening the response time to approximately 0.05ms.

[0053] It is understood that the second sampling frequency can be 20kHz to reduce the response time to 0.05ms. In other embodiments, the second sampling frequency can also be 10kHz, 30kHz, 40kHz, 50kHz, etc. In the embodiments of this application, the specific value of the second sampling frequency is not limited.

[0054] It is understood that the Kalman algorithm is an optimal recursive filtering algorithm for state estimation of dynamic systems. It achieves optimal estimation of state variables in noisy environments by fusing system models and observation data. Exemplarily, the Kalman algorithm commonly uses least squares estimation, linear minimum variance estimation, minimum variance estimation, and recursive least squares estimation. In other embodiments, Bayesian estimation, maximum likelihood estimation, and stochastic approximation can also be used. In this application, no specific limitation is placed on the specific estimation method.

[0055] In this example, controller 33 calculates an error signal based on the actual voltage values ​​Vol12 and Vol22. When this error signal is greater than or equal to the error threshold, it indicates that an anomaly exists in the detection system 3. Controller 33 then controls the switching circuit 34 to be in a second conducting state, enabling controller 33 to locate the specific fault point. Thus, this application can determine the presence of an anomaly through the error signal, providing reliable support for subsequent fault location.

[0056] During the detection process, there may be deviations in the error signal due to external interference. In order to further improve the reliability of the detection, the difference threshold mechanism is triggered when the error signal is greater than or equal to the error threshold and occurs three times in a row.

[0057] The main and auxiliary sampling circuits each meet the voltage change rate screening condition at different voltage levels. However, it's impossible to identify the specific main sampling circuit at this point, meaning the main and auxiliary sampling circuits may switch back and forth. This compromises the stability of the 12V voltage, leading to frequent false alarms due to 12V voltage-related fault protection strategies. Therefore, in one example, the controller 33 is also used to generate a first voltage value Vol15 based on the first sampling signal IN1 and a second voltage value Vol25 based on the second sampling signal IN2. Based on the first voltage value Vol15, the second voltage value Vol25, and the reference voltage V0, it selects one of the first sampling circuit 31 and the second sampling circuit 32 as the main sampling circuit and the other as the auxiliary sampling circuit.

[0058] In this example, the controller 33 can determine the "true" and "false" sampling circuits based on the first voltage value Vol15, the second voltage value Vol25, and the reference voltage V0. Specifically, when the first voltage value Vol15 received by the controller 33 is close to the reference voltage V0, and the deviation between the second voltage value Vol25 and the reference voltage V0 is large, the controller determines that the first sampling circuit 31 corresponding to the first voltage value Vol15 is the "true" sampling circuit, and the second sampling circuit 32 is the "false" sampling circuit. The controller 33 selects the first sampling circuit 31 as the main sampling circuit and the second sampling circuit 32 as the secondary sampling circuit. The reverse is also true, and will not be elaborated further.

[0059] Thus, the controller 33 can determine the "true" sampling circuit and the "false" sampling circuit based on the first voltage value Vol15, the second voltage value Vol25, and the reference voltage V0. Based on the detection results, it selects the "true" sampling circuit as the main sampling circuit and the "false" sampling circuit as the secondary sampling circuit. This avoids the possibility of the main / secondary sampling circuit switching back and forth, which could lead to frequent fault protection strategies and false alarms, thereby improving detection reliability. Secondly, this application can switch to the correct sampling circuit for voltage sampling, achieving the purpose of non-stop detection.

[0060] It is worth noting that this application can also realize a power-on voltage offset self-test function through the controller 33 and the switching circuit 34. Specifically, after the controller 33 is initialized, it controls the switching circuit 34 to be in the second conduction state, so that the switching circuit 34 is connected to the reference voltage V0. The controller 33 samples the voltage values ​​output by the first sampling circuit 31 and the second sampling circuit 32, and converts the voltage values ​​into actual voltage values ​​Vol1 and Vol2 according to the proportional algorithm, and calculates the voltage offset. Based on the voltage offset, it determines whether there is a voltage offset at this time. Specifically, the voltage offset can be calculated according to... EFF1 / EFF2 = 5.0V - Vol1 / Vol2. If the voltage offset EFF1 / EFF2 > the offset threshold, for example, ±0.5V, it indicates that there is a voltage offset. When a voltage offset is detected before power-on, it indicates an abnormality in the sampling circuit. Correspondingly, a fault diagnosis mechanism is triggered, and a fault code is recorded to locate the fault point in the sampling circuit. This process does not stop the power supply. Furthermore, to improve the reliability of detection, this process can be performed multiple times, for example, 10 times. The average of the 10 voltage offsets is then compared with the offset threshold.

[0061] Understandably, when the power-on voltage offset self-test function detects a voltage offset, the detection system 3 will first check for faults in the sampling circuit. When the power-on voltage offset self-test function detects no voltage offset, it means that there is no fault in the sampling circuit at this time, that is, the power-on voltage offset self-test function is completed. Only after the power-on voltage offset self-test function is completed will the detection system 3 test the low-voltage power supply 2.

[0062] In one example, such as Figure 4 As shown, the switching circuit 34 includes a voltage source U and a switching module 341. The voltage source U is connected to the low-voltage power supply 2 and is used to output a reference voltage V0. The first terminal of the switching module 341 serves as the first terminal of the switching circuit 34 and is connected to the low-voltage power supply 2. The second terminal of the switching module 341 serves as the second terminal of the switching circuit 34 and is connected to the voltage source U. The third terminal of the switching module 341 serves as the third terminal of the switching circuit 34 and is connected to the first sampling circuit 31 and the second sampling circuit 32. The controlled terminal of the switching module 341 serves as the controlled terminal of the switching circuit 34 and is connected to the controller 33.

[0063] In this example, the conduction state of the switching circuit 34 can be switched by changing the conduction state of the switching module 341, providing high flexibility. Furthermore, a voltage source U is set to provide a stable reference voltage V0 for the detection system 3, thereby ensuring the reliability of subsequent fault detection and location of the sampling circuit based on this reference voltage V0.

[0064] In one example, such as Figure 5As shown, the switch module 341 includes a relay, which includes a coil L0 and a single-pole double-throw (SPDT) switch. One end of the coil L0 is connected to the low-voltage power supply 2, and the other end of the coil L0 serves as the controlled terminal of the switch module 341 and is connected to the controller 33. The common terminal of the SPDT serves as the third terminal of the switch module 341 and is connected to the first sampling circuit 31 and the second sampling circuit 32. The first switching terminal of the SPDT serves as the first terminal of the switch module 341 and is connected to the low-voltage power supply 2, and the second switching terminal of the SPDT serves as the second terminal of the switch module 341 and is connected to the voltage source U.

[0065] In this example, controller 33 outputs control signal KY1 to coil L0 to control the energization state of coil L0, thereby changing the conduction state of single-pole double-throw switch SPDT. For example, when switch module 341 needs to switch to the second conduction state, controller 33 outputs a high-level control signal KY1 to coil L0, causing coil L0 to be energized and generate a magnetic field, which in turn drives the internal mechanical contacts to change the conduction state of single-pole double-throw switch SPDT, thereby realizing the automatic switching of the overall conduction state of switching circuit 34.

[0066] Thus, by changing the energized state of coil L0, the overall conduction state of switching circuit 34 can be switched, providing high switching flexibility. Secondly, the coil L0 and the single-pole double-throw switch SPDT in the relay are physically isolated, with no direct electrical connection, effectively preventing noise interference and improving the anti-interference capability of switching circuit 34, thereby enhancing the overall safety and reliability of the system.

[0067] Optionally, the switch module 341 may include two independent switches, with the controlled terminals of the two independent switches connected to the controller 33. It is worth noting that when the switch module 341 consists of two independent switches, the on / off states of the two switches are always opposite; that is, when one is on, the other is off, to achieve different output paths. The switch module 341 provided in this application can use the aforementioned devices or other devices or circuits capable of selecting different output paths; this application does not impose specific limitations in this regard.

[0068] It is worth noting that the switching circuit 34 provided in this application is in the first conducting state before receiving the control signal KY1, that is, it is connected to the low-voltage power supply 2.

[0069] In one example, such as Figure 5As shown, both the first sampling circuit 31 and the second sampling circuit 32 include an anti-interference module 311, a temperature drift compensation module 312, and an amplification module 313. The anti-interference module 311 and the temperature drift compensation module 312 are connected in series between the third terminal of the switching circuit 34 and the input terminal of the amplification module 313. The output terminal of the amplification module 313 is connected to the controller 33 and is used to output the first sampling signal IN1.

[0070] The temperature drift compensation module 312 reduces the impact of temperature changes on the output voltage of the acquired low-voltage power supply 2, thereby enhancing the reliability of voltage detection and avoiding detection errors and malfunctions caused by temperature factors. For example, the temperature drift compensation module 312 can automatically adjust circuit parameters to compensate for voltage deviations caused by temperature changes through reasonable configuration of temperature-sensitive components and circuit design.

[0071] The anti-interference module 311 employs various techniques such as filtering and voltage regulation to effectively suppress interference signals, thereby making the voltage signal input to the amplification module 313 purer. This reduces the impact of interference signals on the sampling voltage, improves the accuracy of the acquired sampling voltage, and ultimately enhances the reliability of the entire voltage detection system, thereby improving the accuracy of the acquired low-voltage power supply 2 output voltage.

[0072] The amplification module 313 can amplify the weak signal processed by the temperature drift compensation module 312 and the anti-interference module 311 to a range of amplitude suitable for sampling by the controller 33, so as to improve the accuracy of the obtained output voltage of the power supply 2.

[0073] Thus, the temperature drift compensation module 312, the anti-interference module 311, and the amplification module 313 work together to form a voltage detection front-end processing system. This ensures that under various complex working conditions, the detection circuit 3 can accurately and reliably transmit the output voltage information of the low-voltage power supply 2 to the controller 33, thereby improving the detection accuracy of the output voltage of the low-voltage power supply 2 and providing a reliable guarantee for the continuous acquisition of the output voltage information of the low-voltage power supply 2 by the vehicle controller or battery management system.

[0074] In one example, the anti-interference module 311 includes a common-mode inductor, a filter unit 3111, and an overvoltage protection unit 3112. The positive input terminal of the common-mode inductor is connected to the third terminal of the switching circuit 34, and the negative input terminal of the common-mode inductor is connected to the negative terminal of the low-voltage power supply 2. The input terminal of the filter unit 3111 is connected to both the positive and negative output terminals of the common-mode inductor. The input terminal of the overvoltage protection unit 3112 is connected to the output terminal of the filter unit 3111, and the output terminal of the overvoltage protection unit 3112 is connected to the input terminal of the amplification module 313.

[0075] A common-mode inductor is used to suppress common-mode interference signals at the output of the low-voltage power supply 2, resulting in a cleaner signal input to subsequent circuits and thus improving the accuracy and reliability of voltage detection. The filter unit 3111 further filters out any residual high-frequency noise, further improving the signal quality input to the amplification module 313 and enhancing the stability of voltage detection. For example, the filter unit 3111 typically consists of components such as capacitors and inductors. By rationally designing the parameters and topology of the capacitors and inductors, it can filter interference signals within a specific frequency range.

[0076] When the voltage of the input overvoltage protection unit 3112 exceeds the set threshold, the overvoltage protection unit 3112 can clamp the excessive voltage within a safe range, preventing the excessive voltage from being transmitted to the amplification module 313. This protects the amplification module 313 and the controller 33, thereby reducing the probability of damage to the amplification module 313 and the controller 33, and enabling the amplification module 313 and the controller 33 to have a longer service life. This provides a reliable guarantee for the continuous acquisition of the low-voltage power supply 2 output voltage information by the vehicle controller or battery management system.

[0077] Furthermore, by combining the common-mode inductor, the filter unit 3111, and the overvoltage protection unit 3112 to form a hybrid anti-interference module 311, the first sampling circuit 31 can improve its resistance to various interferences and abnormal voltage conditions, thereby improving the overall anti-interference performance of the detection circuit 3 and providing a reliable guarantee for the vehicle controller or battery management system to continuously acquire information on the output voltage of the low-voltage power supply 2.

[0078] Please refer to Figure 5 In one specific embodiment, the common-mode inductor may include an iron core, a first coil L1, and a second coil L2. The first coil L1 is wound on the iron core in a first direction; the first end of the first coil L1 is the positive input terminal of the common-mode inductor and also the positive input terminal of the first sampling circuit 31, that is, the first end of the first coil L1 is connected to the positive terminal of the low-voltage power supply 2, and the second end of the first coil L1 is the positive output terminal of the common-mode inductor; the second coil L2 is wound on the iron core in a second direction and is spaced apart from the first coil L1; the first end of the second coil L2 is the negative input terminal of the common-mode inductor and also the negative input terminal of the first sampling circuit 31, that is, the first end of the second coil L2 is connected to the negative terminal of the low-voltage power supply 2, and the second end of the second coil L2 is the negative output terminal of the common-mode inductor; wherein, the first direction is opposite to the second direction.

[0079] When common-mode interference signals appear on the positive and negative terminals of the low-voltage power supply 2, these common-mode interference signals will generate induced currents in the first coil L1 and the second coil L2 in the same direction. This will cause the first coil L1 and the second coil L2 to generate magnetic fields in the same direction, thereby increasing the inductive reactance of the first coil L1 and the second coil L2. This will make the first coil L1 and the second coil L2 exhibit high impedance, producing a strong damping effect, thereby attenuating the common-mode current and reducing the impact of common-mode interference signals on the accuracy of voltage detection.

[0080] Optionally, the filter unit 3111 may include a first resistor R1 and a first capacitor C1. The first end of the first resistor R1 is connected to the positive output terminal of the common-mode inductor, and the second end of the first resistor R1 is connected to the overvoltage protection unit 3112. The first plate of the first capacitor C1 is connected to the second end of the first resistor R1, and the second plate of the first capacitor C1 is connected to the negative output terminal of the common-mode inductor. The second plate of the first capacitor C1 is also connected to the overvoltage protection unit 3112.

[0081] A low-pass filter is formed by combining the first resistor R1 and the first capacitor C1 to filter out high-frequency noise and improve the signal quality input to the amplification module 313, thereby improving the stability of the voltage detection acquired by the controller 33. It is understood that in other embodiments, the filter module 314 may also take other forms. In this application embodiment, the specific form of the filter module 314 is not limited.

[0082] In one example, the overvoltage protection unit 3112 includes a transient voltage suppressor diode D1 (TVS). The first terminal of the transient voltage suppressor diode D1 is connected to the first plate of the first capacitor C1 and the amplification module 313, and the second terminal of the transient voltage suppressor diode D1 is connected to the second plate of the first capacitor C1 and the amplification module 313.

[0083] When the positive voltage of the low-voltage power supply 2 exceeds the first threshold voltage, the transient voltage suppression diode D1 can conduct from the first terminal to the second terminal to release the large voltage at the positive terminal of the low-voltage power supply 2. This stabilizes the voltage at the first terminal of the transient voltage suppression diode D1 at the first threshold voltage, preventing the large voltage at the positive terminal of the low-voltage power supply 2 from entering the amplification module 313. This protects the amplification module 313, reduces the probability of damage to the amplification module 313, and allows the amplification module 313 to have a longer service life. Conversely, when the negative voltage of the low-voltage power supply 2 exceeds the second threshold voltage, the transient voltage suppression diode D1 can conduct from the second terminal to the first terminal to release the large voltage at the negative terminal of the low-voltage power supply 2. This stabilizes the voltage at the second terminal of the transient voltage suppression diode D1 at the second threshold voltage, preventing the large voltage at the negative terminal of the low-voltage power supply 2 from entering the amplification module 313. It also prevents the large voltage from entering the amplification module 313, thereby protecting the amplification module 313 and reducing the probability of damage to the amplification module 313, so that the amplification module 313 can have a longer service life.

[0084] It is understood that the values ​​of the first threshold voltage and the second threshold voltage are determined by the characteristics of the transient voltage suppression diode D1 itself. Therefore, a suitable transient voltage suppression diode D1 can be selected according to the rated voltage of the amplification module 313, thereby protecting the amplification module 313. In this embodiment, no specific limitation is made on the values ​​of the first threshold voltage and the second threshold voltage.

[0085] It is understood that the overvoltage protection unit 3112 can also be obtained by connecting two Zener diodes in reverse series, which can also prevent high voltage from entering the amplification module 313. In other embodiments, the overvoltage protection circuit can also take other forms. In the embodiments of this application, the specific form of the overvoltage protection unit 3112 is not limited.

[0086] Please refer to Figure 5 In one specific embodiment, the temperature drift compensation module 312 includes a second resistor R2 and a thermistor NTC. The first end of the second resistor R2 is connected to the positive output terminal of the common-mode inductor, and the second end of the second resistor R2 is connected to the second end of the first resistor R1, so that the first end of the first resistor R1 is connected to the positive output terminal of the common-mode inductor through the second resistor R2. The first end of the thermistor NTC is connected to the second end of the second resistor R2, and the second end of the thermistor NTC is connected to the negative output terminal of the common-mode inductor.

[0087] A resistor voltage divider network is formed by connecting the second resistor R2 and the thermistor NTC in series. When the ambient temperature of the second resistor R2 and the thermistor NTC changes, the resistance values ​​of the second resistor R2 and the thermistor NTC will change synchronously, so that the voltage division ratio of the second resistor R2 and the thermistor NTC remains unchanged. This ensures that the voltage ratio on the thermistor NTC does not change with temperature, thereby eliminating the change in the voltage division ratio in the resistor voltage divider network caused by temperature changes. In this way, the influence of temperature changes on the output signal of the amplification module 313 is eliminated, thereby improving the accuracy of the acquired detection voltage.

[0088] For example, the B value of the thermistor NTC can always be 3950K (the B value is also called the material constant or thermistor index, reflecting the temperature sensitivity of the thermistor material). Of course, the B value of the thermistor NTC can also be other values, which can be selected according to the corresponding design requirements. In the embodiments of this application, no specific limitation is made in this regard.

[0089] Please refer to Figure 5 In this embodiment, the thermistors (NTCs) can all be negative temperature coefficient (NTC) thermistors. Combined with the fact that the B value of all NTC thermistors is 3950K, this reduces the maximum measurement error of the detection circuit 3 within its operating temperature range (-40℃ to 125℃) from ±1.8% to ±0.2%. It is understood that the thermistors (NTCs) can also all be positive temperature coefficient (PTC) thermistors.

[0090] Please refer to Figure 5 In one specific embodiment, the amplification module 313 includes an operational amplifier U1. The non-inverting input terminal of the operational amplifier U1 is connected to the first terminal of the transient voltage suppressor diode D1, the inverting input terminal of the operational amplifier U1 is connected to the second terminal of the transient voltage suppressor diode D1, and the output terminal of the operational amplifier U1 is the output terminal of the amplification module 313 and is connected to the controller 33.

[0091] The non-inverting input of operational amplifier U1 is connected to the first terminal of transient voltage suppressor diode D1, and the inverting input of operational amplifier U1 is connected to the second terminal of transient voltage suppressor diode D1. This enables operational amplifier U1 to amplify the voltage signal processed by anti-interference module 311, reducing attenuation and distortion during signal transmission. It also facilitates the controller 33 in sampling, analog-to-digital conversion, and subsequent processing of the output signal of operational amplifier U1, further enhancing the reliability of the entire voltage detection system.

[0092] Furthermore, since the non-inverting and inverting input terminals of operational amplifier U1 are connected to the two ends of transient voltage suppressor diode D1 respectively, operational amplifier U1 receives differential signals, which can effectively suppress the influence of differential signals and improve the accuracy of voltage detection.

[0093] Please refer to Figure 5 Specifically, the operational amplifier U1 can be a low bias voltage and low temperature drift operational amplifier, which can reduce the impact of voltage and temperature changes on the output signal of the operational amplifier U1, so that the controller 33 can sample, convert analog to digital and perform subsequent processing on the output signal of the operational amplifier U1, and further improve the accuracy of voltage detection.

[0094] In one example, such as Figure 5 As shown, the first sampling circuit 31 also includes a filtering module 314, which is connected in series between the output of the amplification module 313 and the controller 33.

[0095] In this example, the voltage signal amplified by the amplification module 313 is further filtered by the filtering module 314 to make the signal transmitted to the controller 33 purer, thereby further improving the accuracy of voltage detection. Furthermore, the filtering module 314 can smooth the signal, reducing signal fluctuations and jitter, thus making the voltage signal transmitted to the controller 33 more stable. This allows the controller 33 to sample and process the voltage signal more accurately, thereby improving the reliability and accuracy of the entire voltage detection system.

[0096] Please refer to Figure 5 Specifically, the filter module 314 includes a third resistor R3 and a second capacitor C2. The first end of the third resistor R3 is connected to the output end of the amplifier module 313, and the second end of the third resistor R3 is connected to the controller 33. The first plate of the second capacitor C2 is connected to the second end of the third resistor R3, and the second plate of the second capacitor C2 is grounded.

[0097] The first-order low-pass filter, composed of the third resistor R3 and the second capacitor C2, can suppress high-frequency noise, enabling the controller 33 to sample and process the voltage signal more accurately, thereby improving the reliability and accuracy of the entire voltage detection system.

[0098] Please refer to Figure 5 In this embodiment, the cutoff frequency of the first-order low-pass filter composed of the third resistor R3 and the second capacitor C2 can be 10kHz. That is, the first-order low-pass filter composed of the third resistor R3 and the second capacitor C2 can filter out signals with frequencies greater than 10kHz. In this application, it is mainly used to suppress high-frequency switching noise, i.e., PWM noise, of the electric drive system on the output side of power supply 2.

[0099] When the first sampling circuit 31 and the second sampling circuit 32 include the aforementioned devices, the fault diagnosis mechanism provided in this application can locate faults according to Table 1 below. It is worth noting that, in this table, channel 1 represents the sampling voltage value of the first sampling circuit 31 when the switching circuit 34 is in the first conducting state; channel 2 represents the sampling voltage value of the second sampling circuit 32 when the switching circuit 34 is in the first conducting state; channel 15 represents the sampling voltage value of the first sampling circuit 31 when the switching circuit 34 is in the second conducting state; and channel 25 represents the sampling voltage value of the second sampling circuit 32 when the switching circuit 34 is in the second conducting state. K1 represents the voltage conversion ratio of the first sampling circuit 31, and K2 represents the voltage conversion ratio of the second sampling circuit 32.

[0100]

[0101] Table 1 Table 1 shows 3-6 abnormalities in the first sampling circuit 31 and its internal components, and Table 1 shows 7-10 abnormalities in the second sampling circuit 32 and its internal components. When the switching circuit 34 is in the first conducting state, the controller 33 acquires the voltage values ​​in channels 1 and 2. When the controller 33 detects an abnormality, it controls the switching circuit 34 to be in the second conducting state and acquires the corresponding voltage values ​​in channels 15 and 25. The acquired voltage values ​​are then compared with the voltage thresholds in channels 1 and 2 to determine whether the fault lies in the sampling circuit or the switching circuit. If the fault is located in the sampling circuit, the controller determines the specific faulty component or fault state within that sampling circuit.

[0102] For example, taking a short circuit in the thermistor NTC in the first sampling circuit 31 as an example, when the controller 33 receives a value of 0V in channel 15 and a value of 5V in channel 25, it indicates that the fault point is the thermistor NTC in the first sampling circuit 31, and the fault type is a short circuit in the thermistor NTC. It is worth noting that the above examples only illustrate these fault types; other fault types can also be used to set corresponding fault values. This application does not impose specific limitations on this.

[0103] In summary, when the controller 33 determines that there is no abnormality based on the first sampling signal IN1 and the second sampling signal IN2, the switching circuit 34 is in the first conducting state. At this time, the controller 33 performs real-time detection of the voltage of the low-voltage power supply 2 based on the first sampling signal IN1 and the second sampling signal IN2 to achieve detection of the low-voltage power supply 2. At this time, the detection system performs the voltage detection function. When the controller 33 determines that there is an abnormality based on the first sampling signal IN1 and the second sampling signal IN2, the controller 33 will control the switching circuit 34 to be in the second conducting state. At this time, the first sampling circuit 31 and the second sampling circuit 32 will generate the first detection signal and the second detection signal based on the reference voltage V0. The controller 33 can determine whether there is a fault in the sampling circuit based on the first detection signal and the second detection signal. At this time, the detection system performs the fault location function. If it is determined that there is no abnormality in the sampling circuit based on the detection signals, it means that there is an abnormality in the low-voltage power supply 2. At this time, the system triggers the protection action to prevent the abnormality of the low-voltage power supply 2 from affecting the normal use of the vehicle. If the detection signal indicates an abnormality in one of the sampling circuits, the controller 33 determines whether the low-voltage power supply 2 is also abnormal based on the sampling signal output from the other sampling circuit that is not abnormal. This ensures the continuity of the detection of the low-voltage power supply 2 and avoids detection interruption. If the detection signal indicates that both sampling circuits are abnormal, the detection system cannot continue to detect the low-voltage power supply 2 and must report the issue for repair. Thus, by controlling the conduction state of the switching circuit 34, this application can detect the low-voltage power supply 2 and accurately identify whether the abnormality is due to a fault in the low-voltage power supply 2 or a fault in the sampling circuit. This avoids false voltage alarms caused by sampling circuit faults, which could trigger unnecessary protection actions (such as power outages or alarms) and affect the normal operation of the vehicle. This improves system availability to 100%, reduces the false alarm rate to >96%, and ensures the detection reliability of the system and the reliability of the vehicle.

[0104] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0105] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0106] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A detection system applied to a vehicle, characterized in that, The detection system includes: A switching circuit, wherein the first terminal of the switching circuit is connected to a low-voltage power supply, and the second terminal of the switching circuit is connected to a reference voltage; A first sampling circuit is connected to the third terminal of the switching circuit, and the first sampling circuit is used to output a first sampling signal. A second sampling circuit is connected to the third terminal of the switching circuit and the first sampling circuit, and the second sampling circuit is used to output a second sampling signal; and, A controller is connected to the controlled terminals of the first sampling circuit, the second sampling circuit, and the switching circuit. The controller receives the first sampling signal and the second sampling signal, and controls the conduction state of the switching circuit based on the first sampling signal and the second sampling signal. The switching circuit has a first conducting state and a second conducting state. In the first conducting state, the first terminal of the switching circuit is connected to the third terminal of the switching circuit. In the second conducting state, the second terminal of the switching circuit is connected to the third terminal of the switching circuit.

2. The detection system of claim 1, wherein, The switching circuit includes: A voltage source, connected to the low-voltage power supply, wherein the voltage source is used to output the reference voltage; and, The switching module has a first terminal connected to the low-voltage power supply as the first terminal of the switching circuit, a second terminal connected to the voltage source as the second terminal of the switching circuit, a third terminal connected to the first sampling circuit and the second sampling circuit as the third terminal of the switching circuit, and a controlled terminal connected to the controller as the controlled terminal of the switching circuit.

3. The detection system of claim 2, wherein, The switching module includes a relay, the relay comprising: A coil, one end of which is connected to the low-voltage power supply, and the other end of which serves as the controlled terminal of the switching module and is connected to the controller; and, A single-pole double-throw switch is provided, wherein the common terminal of the single-pole double-throw switch serves as the third terminal of the switch module and is connected to the first sampling circuit and the second sampling circuit; the first switching terminal of the single-pole double-throw switch serves as the first terminal of the switch module and is connected to the low-voltage power supply; and the second switching terminal of the single-pole double-throw switch serves as the second terminal of the switch module and is connected to the voltage source.

4. The detection system of claim 1, wherein, The controller is used to generate an error signal based on the first sampling signal and the second sampling signal, and when the error signal is greater than or equal to an error threshold, control the switching circuit to be in the second conduction state.

5. The detection system of claim 4, wherein, The controller is further configured to generate a first voltage value based on the first sampling signal and a second voltage value based on the second sampling signal, and select one of the first sampling circuit and the second sampling circuit as a main sampling circuit and the other as a sub-sampling circuit based on the first voltage value, the second voltage value and the reference voltage.

6. The detection system according to any one of claims 1 to 5, characterized in that Both the first sampling circuit and the second sampling circuit include an anti-interference module, a temperature drift compensation module, and an amplification module; The anti-interference module and the temperature drift compensation module are connected in series between the third terminal of the switching circuit and the input terminal of the amplification module. The output terminal of the amplification module is connected to the controller and is used to output the first sampling signal.

7. The detection system of claim 6, wherein, The first sampling circuit and the second sampling circuit further include: A filtering module is connected in series between the output of the amplification module and the controller.

8. The detection system of claim 6, wherein, The anti-interference module includes: A common-mode inductor, wherein the positive input terminal of the common-mode inductor is connected to the third terminal of the switching circuit, and the negative input terminal of the common-mode inductor is connected to the negative terminal of the low-voltage power supply; A filtering unit, wherein the input terminal of the filtering unit is connected to the positive and negative output terminals of the common-mode inductor; and, An overvoltage protection unit is provided, the input of which is connected to the output of the filter unit, and the output of which is connected to the input of the amplification module.

9. The detection system of claim 8, wherein, The overvoltage protection unit includes: A transient voltage suppressor diode is provided, with its first terminal connected to the output terminal of the filter unit and the input terminal of the amplification module, and its second terminal connected to the negative output terminal of the common-mode inductor and the input terminal of the amplification module.

10. A vehicle characterized by comprising: The vehicles include: Body; A low-voltage power supply is located within the vehicle body; and The detection system according to any one of claims 1 to 9 is disposed inside the vehicle body and connected to the output terminal of the low-voltage power supply.

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