Voltage acquisition circuit, device and system

Abstract

The invention provides a voltage acquisition circuit, device and system, and relates to the technical field of function safety, the voltage acquisition circuit comprises a channel sampling circuit, a first conversion circuit, a second conversion circuit, a first control circuit, a second control circuit and a cross mutual diagnosis circuit; the channel sampling circuit is connected with an external circuit, the first conversion circuit and the second conversion circuit are connected with the channel sampling circuit, the first control circuit and the second control circuit are connected with the first conversion circuit, and the second control circuit is connected with the second conversion circuit. The cross mutual diagnosis circuit is connected with the first conversion circuit, the second conversion circuit, the first control circuit and the second control circuit. According to the voltage acquisition circuit architecture, fault diagnosis of the self state of the voltage acquisition circuit can be realized under a single module, and fault diagnosis of the conversion circuit can also be realized, so that the safety and reliability of voltage acquisition are ensured, the complex module redundancy design is reduced, and the function safety level is improved at the same time.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of functional safety technology, and in particular to a voltage acquisition circuit, device and system. Background Technology

[0002] With the continuous development of industrial control systems, the demands for the safety and reliability of signal acquisition are also increasing. Safe analog voltage input modules rely on hardware architecture design, fault diagnosis mechanisms, and safety mechanisms. Compared to traditional voltage input modules, safe analog voltage modules need to ensure they reach the corresponding safety level through fault diagnosis schemes and safety mechanisms, reducing the risks during use.

[0003] However, current conventional analog voltage acquisition circuits lack fault diagnosis, making it impossible to guarantee the accuracy of the acquired values ​​in the event of a circuit failure. Furthermore, insufficient coverage of fault detection makes it difficult to meet functional safety requirements, resulting in a lack of a safety rating. To achieve a high functional safety rating, conventional analog voltage acquisition circuits typically employ complex modular redundancy designs, increasing design cost and size. Therefore, reducing the complexity of modular redundancy in analog voltage acquisition circuits and improving their functional safety rating has become a critical issue that urgently needs to be addressed. Summary of the Invention

[0004] This invention provides a voltage acquisition circuit, device, and system to address the problems of complex redundant design and low functional safety level in existing analog voltage acquisition circuit modules.

[0005] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0006] In a first aspect, embodiments of the present invention provide a voltage acquisition circuit, the voltage acquisition circuit including a channel sampling circuit, a first conversion circuit, a second conversion circuit, a first control circuit, a second control circuit, and a cross-diagnosis circuit;

[0007] The channel sampling circuit is connected to an external circuit, the first conversion circuit and the second conversion circuit are connected to the channel sampling circuit, the first control circuit is connected to the second control circuit and the first conversion circuit, the second control circuit is connected to the second conversion circuit, and the cross-diagnosis circuit is connected to the first conversion circuit, the second conversion circuit, the first control circuit and the second control circuit.

[0008] The channel sampling circuit is used to acquire the external voltage signal output by the external circuit. The first conversion circuit is used to convert the external voltage signal into a first voltage signal. The second conversion circuit is used to convert the external voltage signal into a second voltage signal. The first control circuit is used to receive the first voltage signal and send the first voltage signal to the second control circuit. The second control circuit is used to receive the second voltage signal and send the second voltage signal to the first control circuit. The first control circuit and the second control circuit are used to compare the first voltage signal and the second voltage signal respectively to diagnose whether the voltage acquisition circuit is faulty.

[0009] The second control circuit sends a first diagnostic signal to the first control circuit through the cross-diagnostic circuit and the first conversion circuit, so that the first control circuit can diagnose whether the first conversion circuit is faulty based on the first diagnostic signal; the first control circuit sends a second diagnostic signal to the second control circuit through the cross-diagnostic circuit and the second conversion circuit, so that the second control circuit can diagnose whether the second conversion circuit is faulty based on the second diagnostic signal.

[0010] Optionally, the cross-diagnosis circuit includes a first switching circuit and a second switching circuit;

[0011] The first switching circuit is connected to the first conversion circuit and the second control circuit, and the second switching circuit is connected to the second conversion circuit and the first control circuit.

[0012] The second control circuit sends the first diagnostic signal to the first control circuit through the first switching circuit and the first conversion circuit. The first control circuit diagnoses whether the first conversion circuit has malfunctioned based on the first diagnostic signal. The first control circuit sends the second diagnostic signal to the first control circuit through the second switching circuit and the second conversion circuit. The second control circuit diagnoses whether the second conversion circuit has malfunctioned based on the second diagnostic signal.

[0013] Optionally, the cross-diagnosis circuit further includes a first amplifier circuit and a second amplifier circuit;

[0014] The first amplifier circuit is connected to the first control circuit and the second switch circuit, and the second amplifier circuit is connected to the second control circuit and the first switch circuit.

[0015] The second control circuit sends the first diagnostic signal to the first control circuit through the second amplifier circuit, the first switch circuit, and the first conversion circuit. The first control circuit diagnoses whether the first conversion circuit has malfunctioned based on the first diagnostic signal. The first control circuit sends the second diagnostic signal to the second control circuit through the first amplifier circuit, the second switch circuit, and the second conversion circuit. The second control circuit diagnoses whether the second conversion circuit has malfunctioned based on the second diagnostic signal.

[0016] Optionally, the channel sampling circuit includes at least a first sampling circuit and a second sampling circuit, and the external circuit includes at least a first external circuit and a second external circuit;

[0017] The first sampling circuit is connected to the first external circuit, and the second sampling circuit is connected to the second external circuit;

[0018] The first control circuit is used to acquire a first external voltage signal output by the first external circuit through the first conversion circuit and the first sampling circuit, and to acquire a second external voltage signal output by the second external circuit through the first conversion circuit and the second sampling circuit, and to send the first external voltage signal and the second external voltage signal to the second control circuit; the second control circuit is used to acquire a third external voltage signal output by the first external circuit through the second conversion circuit and the first sampling circuit, and to acquire a fourth external voltage signal output by the second external circuit through the second conversion circuit and the second sampling circuit, and to send the third external voltage signal and the fourth external voltage signal to the first control circuit;

[0019] The first control circuit is used to compare the first external voltage signal and the third external voltage signal. When the first external voltage signal and the third external voltage signal meet a preset condition, it generates a first target voltage signal and sends the first target voltage signal to the second control circuit. The second control circuit is used to compare the first external voltage signal and the third external voltage signal. When the first external voltage signal and the third external voltage signal meet a preset condition, it generates a second target voltage signal and sends the second target voltage signal to the first control circuit. The first control circuit and the second control circuit are used to compare the first target voltage signal and the second target voltage signal respectively. When the first target voltage signal and the second target voltage signal meet a preset condition, they generate a third target voltage signal.

[0020] The first control circuit is used to compare the second external voltage signal and the fourth external voltage signal. When the second external voltage signal and the fourth external voltage signal meet a preset condition, a fourth target voltage signal is generated and sent to the second control circuit. The second control circuit is used to compare the second external voltage signal and the fourth external voltage signal. When the second external voltage signal and the fourth external voltage signal meet a preset condition, a fifth target voltage signal is generated and sent to the first control circuit. The first control circuit and the second control circuit are used to compare the fourth target voltage signal and the fifth target voltage signal respectively. When the fourth target voltage signal and the fifth target voltage signal meet a preset condition, a sixth target voltage signal is generated.

[0021] The first control circuit and the second control circuit are used to compare the third target voltage signal and the sixth target voltage signal respectively to diagnose whether the output voltage of the first external circuit and the second external circuit is faulty.

[0022] Optionally, the channel sampling circuit includes a sampling resistor, a third switching circuit, and a fourth switching circuit;

[0023] The sampling resistor is connected to the third switching circuit, the fourth switching circuit, and the external circuit. The third switching circuit is connected to the first conversion circuit, and the fourth switching circuit is connected to the second conversion circuit.

[0024] Optionally, the sampling resistor includes a first sampling resistor and a second sampling resistor connected in parallel; the first sampling resistor is connected to the third switching circuit, the fourth switching circuit and the external circuit, and the second sampling resistor is connected to the third switching circuit, the fourth switching circuit and the external circuit.

[0025] Optionally, the channel sampling circuit further includes a protection circuit; the protection circuit is connected to the sampling resistor, the third switching circuit, and the fourth switching circuit.

[0026] Optionally, the first conversion circuit and the second conversion circuit are analog-to-digital converters.

[0027] In a second aspect, embodiments of the present invention provide a voltage acquisition device, the voltage acquisition device including the voltage acquisition circuit as described in the first aspect.

[0028] Thirdly, embodiments of the present invention provide a voltage acquisition system, the voltage acquisition system including a host device and at least one voltage acquisition device as described in the second aspect, the host device and the voltage acquisition device being connected via a communication bus.

[0029] In this invention, a voltage acquisition circuit is provided, comprising a channel sampling circuit, a first conversion circuit, a second conversion circuit, a first control circuit, a second control circuit, and a cross-diagnostic circuit. The channel sampling circuit is connected to an external circuit; the first and second conversion circuits are connected to the channel sampling circuit; the first control circuit is connected to the second control circuit and the first conversion circuit; the second control circuit is connected to the second conversion circuit; and the cross-diagnostic circuit is connected to the first conversion circuit, the second conversion circuit, the first control circuit, and the second control circuit. The channel sampling circuit is used to acquire the external voltage signal output by the external circuit; the first conversion circuit is used to convert the external voltage signal into a first voltage signal; and the second conversion circuit is used to convert the external voltage signal into a second voltage signal. The first control circuit receives the first voltage signal and sends it to the second control circuit. The second control circuit receives the second voltage signal and sends it to the first control circuit. The first and second control circuits compare the first and second voltage signals respectively to diagnose whether the voltage acquisition circuit is faulty. The second control circuit sends a first diagnostic signal to the first control circuit through the cross-diagnosis circuit and the first conversion circuit. The first control circuit diagnoses whether the first conversion circuit is faulty based on the first diagnostic signal. The first control circuit sends a second diagnostic signal to the second control circuit through the cross-diagnosis circuit and the second conversion circuit. The second control circuit diagnoses whether the second conversion circuit is faulty based on the second diagnostic signal. The voltage acquisition circuit of this invention has a cross-diagnostic circuit architecture, enabling fault diagnosis of the voltage acquisition circuit's own state within a single module, while also enabling fault diagnosis of the first and second conversion circuits. This ensures the safety and reliability of voltage acquisition, reduces complex module redundancy design, improves functional safety level, and solves the problems of complex module redundancy design and low functional safety level in existing analog voltage acquisition circuits. Attached Figure Description

[0030] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0031] Figure 1 This is a schematic diagram of a voltage acquisition circuit provided in an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of a voltage acquisition circuit analog-to-digital converter test template diagnostic circuit provided in an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of a voltage acquisition circuit for 1001 evaluation application provided in an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the structure of a voltage acquisition circuit for 1oo2 evaluation application provided in an embodiment of the present invention. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please refer to Figures 1-3 This invention provides a voltage acquisition circuit 100, which includes a channel sampling circuit 1, a first conversion circuit 2, a second conversion circuit 3, a first control circuit 4, a second control circuit 5, and a cross-diagnosis circuit 6.

[0037] Channel sampling circuit 1 is connected to an external circuit; first conversion circuit 2 and second conversion circuit 3 are connected to channel sampling circuit 1; first control circuit 4 is connected to second control circuit 5 and first conversion circuit 2; second control circuit 5 is connected to second conversion circuit 3; cross-diagnosis circuit 6 is connected to first conversion circuit 2, second conversion circuit 3, first control circuit 4 and second control circuit 5. Channel sampling circuit 1 is used to acquire the external voltage signal output by the external circuit; first conversion circuit 2 is used to convert the external voltage signal into a first voltage signal; second conversion circuit 3 is used to convert the external voltage signal into a second voltage signal; first control circuit 4 is used to receive the first voltage signal and send it to second control circuit 5; second control circuit 5 is used to receive the second voltage signal and send it to first control circuit 4; first control circuit 4 and second control circuit 5 are used to compare the first voltage signal and the second voltage signal respectively to diagnose whether the voltage acquisition circuit is faulty.

[0038] The second control circuit 5 sends a first diagnostic signal to the first control circuit 4 through the cross-diagnostic circuit 6 and the first conversion circuit 2, so that the first control circuit 4 can diagnose whether the first conversion circuit 2 is faulty based on the first diagnostic signal; the first control circuit 4 sends a second diagnostic signal to the second control circuit 5 through the cross-diagnostic circuit 6 and the second conversion circuit 3, so that the second control circuit 5 can diagnose whether the second conversion circuit 3 is faulty based on the second diagnostic signal.

[0039] In this embodiment, the external circuit can be an external sensor, such as a voltage sensor, and the channel sampling circuit 1 is directly connected to the external sensor; in other embodiments, the external circuit can be determined according to actual needs, and this embodiment does not limit it.

[0040] In this embodiment, the first conversion circuit 2 and the second conversion circuit 3 are analog-to-digital converters (ADCs); in other embodiments, the first conversion circuit 2 and the second conversion circuit 3 may also be circuits with analog-to-digital conversion functions built from discrete components, and this embodiment does not limit this.

[0041] In this embodiment, the first control circuit 4 and the second control circuit 5 can be microcontroller units (MCUs), and the first control circuit 4 and the second control circuit 5 can communicate with each other through the MCU_BUS bus or other universal serial data buses. In other embodiments, the first control circuit 4 and the second control circuit 5 can also be CPUs, system-on-a-chips, integrated control chips, or programmable devices, or other devices with control processing functions. The first control circuit 4 and the second control circuit 5 can also be circuits with control processing functions built from discrete components. The communication method between the first control circuit 4 and the second control circuit 5 can be determined according to the actual situation, and this embodiment does not limit it.

[0042] In this embodiment, the external voltage signal is an analog signal, and the first voltage signal and the second voltage signal are digital signals converted by the first conversion circuit 2 and the second conversion circuit 3. The first voltage signal and the second voltage signal can be the code value of the voltage corresponding to the external voltage signal. After the first control circuit 4 collects the code value of the external voltage signal through the channel sampling circuit 1 and the first conversion circuit 2, it sends the code value to the second control circuit 5. Similarly, after the second control circuit 5 collects the code value corresponding to the external voltage signal through the channel sampling circuit 1 and the second conversion circuit 3, it sends the code value to the second control circuit 4. The first control circuit 4 and the second control circuit 5 compare the code value they have collected with the code value received from each other. When the comparison result is within the safe accuracy range, it indicates that the voltage acquisition circuit itself has not malfunctioned. Otherwise, it indicates that the voltage acquisition circuit itself has malfunctioned and reports the fault.

[0043] It should be noted that the fault in the voltage acquisition circuit itself can refer to the fault of each circuit component in the voltage acquisition circuit, such as the switch failing to close, capacitor short-circuiting, resistor failure, etc.

[0044] In this embodiment, the first diagnostic signal and the second diagnostic signal can be diagnostic code values ​​corresponding to the voltage signals. The second control circuit 5 sends diagnostic code values ​​to the first control circuit 4 through the cross-diagnosis circuit 6 and the first conversion circuit 2. The first control circuit 4 compares the diagnostic code value received from the first conversion circuit 2 with its preset diagnostic code value. When the comparison result is within the safe accuracy range, it indicates that the first conversion circuit 2 is functioning normally and has not malfunctioned. Otherwise, it indicates that the first conversion circuit 2 is malfunctioning and has malfunctioned. The diagnostic logic of the second conversion circuit 3 is similar and will not be described in detail here.

[0045] It should be noted that the first diagnostic signal and the second diagnostic signal can also be other signals that can be used for diagnosis, and this embodiment does not limit them.

[0046] It should be noted that the faults of the first conversion circuit 2 (ADC1) and the second conversion circuit 3 (ADC2) can specifically refer to abnormalities such as the ADC on-chip resistor voltage divider network, BUFFER, ADC, digital filter, serial communication and other signal link parts, as well as the ADC register bits being stuck or stuck.

[0047] In this embodiment, taking the diagnosis of the first conversion circuit 2, i.e., ADC2, as an example, the first control circuit 4 (i.e., MCUA) outputs voltage to the second control circuit 5 (i.e., MCUB) through ADC2 according to the diagnostic code values ​​0x66, 0x55, 0xAA, and 0x87 respectively. The second control circuit 5 (MCUB) compares the preset diagnostic code value with the diagnostic code value received from ADC2. When the comparison result is within the safe accuracy range, ADC2 is judged to be normal; otherwise, ADC2 is judged to be faulty, and the fault is reported, while the voltage acquisition value is reported as 0. The diagnostic mechanism for ADC1 is the same as above, so it will not be described again. Through this mechanism, the on-chip resistor voltage divider network, buffer, ADC, digital filter, serial communication and other signal link parts of the ADC can be diagnosed, as well as the ADC register bit jamming and sticking. By diagnosing the ADC, the reliability and safety of the system can be improved, the accuracy of voltage acquisition can be guaranteed, maintenance costs can be reduced, and the user experience can be improved.

[0048] In this embodiment, the voltage acquisition circuit 100, composed of the first control circuit 4, the second control circuit 5, the first conversion circuit 2, the second conversion circuit 3, and the channel sampling circuit 1, can perform cross-comparison of external voltages, realize cross-verification of the circuit's own safety status, enhance the system's fault tolerance, redundancy, and reliability, and improve the safety level of voltage acquisition.

[0049] In this embodiment, by setting up a cross-diagnosis circuit 6 to diagnose whether the first conversion circuit 2 and the second conversion circuit 3 are faulty, the reliability and safety of the system are improved, the accuracy of voltage acquisition is guaranteed, maintenance costs are reduced, and the user experience is enhanced.

[0050] In this embodiment, the voltage acquisition circuit 100 has a cross-diagnostic circuit architecture. On the one hand, it can cross-compare external voltage signals; on the other hand, it can diagnose whether the first conversion circuit 2 and the second conversion circuit 3 have malfunctioned through the cross-diagnostic circuit 6. With a single module, it can diagnose both the voltage acquisition circuit's own state and the conversion circuits, ensuring the safety and reliability of voltage acquisition, reducing complex module redundancy design, and improving the functional safety level. This solves the problem of complex redundancy design and low functional safety level in existing analog voltage acquisition circuit modules. Through the above two diagnostic methods, this embodiment, when using 1001 evaluation, achieves a safety level of SIL 3 / PLd / Cat. 3 by cross-comparing the output voltage of one external sensor through one channel, greatly improving the safety of voltage acquisition.

[0051] In one embodiment, please refer to Figure 2 The cross-diagnosis circuit 6 includes a first switching circuit 61 and a second switching circuit 62;

[0052] The first switching circuit 61 is connected to the first conversion circuit 2 and the second control circuit 5, and the second switching circuit 62 is connected to the second conversion circuit 3 and the first control circuit 4.

[0053] The second control circuit 5 sends a first diagnostic signal to the first control circuit 4 through the first switch circuit 61 and the first conversion circuit 2. The first control circuit 4 diagnoses whether the first conversion circuit 2 has malfunctioned based on the first diagnostic signal. The first control circuit 4 sends a second diagnostic signal to the second control circuit 5 through the second switch circuit 62 and the second conversion circuit 3. The second control circuit 5 diagnoses whether the second conversion circuit 3 has malfunctioned based on the second diagnostic signal.

[0054] In this embodiment, the cross-diagnostic circuit 6, i.e., the analog-to-digital converter test pattern diagnostic circuit (ADC testpattern link), includes a first switch circuit 61 and a second switch circuit 62. The first switch circuit 61 and the second switch circuit 62 are used to control the on / off state of the circuit. The first switch circuit 61 and the second switch circuit 62 can be analog switches. In other embodiments, the first switch circuit 61 and the second switch circuit 62 can also be other devices that can control the on / off state of the circuit, or circuits built from discrete components. This embodiment does not limit this.

[0055] In this embodiment, the second control circuit 5 outputs a switch control signal to the first switch circuit 61, causing the first switch circuit 61 to conduct. The electrical signal can then be transmitted to the first control circuit 4 via the first switch circuit 61 and the first conversion circuit 2, allowing the first control circuit 4 to diagnose whether the first conversion circuit 2 has malfunctioned based on the first diagnostic signal. Conversely, when the first switch circuit 61 is disconnected, the circuit is broken, thereby disconnecting the connection between the second control circuit 5 and the first control circuit 4. Similarly, the first control circuit 4 outputs a switch control signal to the second switch circuit 62, causing the second switch circuit 62 to conduct. The electrical signal can then be transmitted to the second control circuit 5 via the second switch circuit 62 and the second conversion circuit 3, allowing the second control circuit 5 to diagnose whether the first conversion circuit 2 has malfunctioned based on the second diagnostic signal. Conversely, when the switch control signal is disconnected, the second switch circuit 62 is disconnected, the circuit is cut off, thereby disconnecting the connection between the second control circuit 5 and the first control circuit 4.

[0056] In this embodiment, the first switching circuit 61 and the second switching circuit 62 are used to turn the diagnostic circuit on and off. The circuit structure is simple. At the same time, the first diagnostic signal and the second diagnostic signal are used to diagnose the first conversion circuit 2 and the second conversion circuit 3, which improves the reliability and safety of the system, ensures the accuracy of voltage acquisition, reduces maintenance costs, and improves the user experience.

[0057] In one embodiment, please refer to Figure 2 The cross-diagnostic circuit 6 also includes a first amplifier circuit 63 and a second amplifier circuit 64;

[0058] The first amplifier circuit 63 is connected to the first control circuit 4 and the second switch circuit 62, and the second amplifier circuit 64 is connected to the second control circuit 5 and the first switch circuit 61.

[0059] The second control circuit 5 sends the first diagnostic signal to the first control circuit 4 through the second amplifier circuit 64, the first switch circuit 61, and the first conversion circuit 2. The first control circuit 4 diagnoses whether the first conversion circuit 2 has malfunctioned based on the first diagnostic signal. The first control circuit 4 sends the second diagnostic signal to the second control circuit 5 through the first amplifier circuit 63, the second switch circuit 62, and the second conversion circuit 3. The second control circuit 5 diagnoses whether the second conversion circuit 3 has malfunctioned based on the second diagnostic signal.

[0060] In this embodiment, the first amplifier circuit 63 and the second amplifier circuit 64 can be operational amplifiers. In other embodiments, the first amplifier circuit 63 and the second amplifier circuit 64 can also be other devices that can amplify electrical signals or circuits built from discrete devices. This embodiment does not limit this.

[0061] In this embodiment, taking the diagnosis of the second conversion circuit 3, i.e., the diagnosis of ADC2, as an example, the first control circuit 4 (MCUA) outputs voltage to the first amplifier circuit 63 according to the diagnostic code values ​​0x66, 0x55, 0xAA, and 0x87 respectively. After the first amplifier circuit 63 amplifies the diagnostic signal gain, it is output to the second control circuit 5 through the second switching circuit 62 and ADC2. The second control circuit 5 (MCUB) compares the preset diagnostic code value with the diagnostic code value received from ADC2. When the comparison result is within the safe accuracy range, it determines that ADC2 is normal; otherwise, it determines that ADC2 is faulty and reports the fault, while also reporting the collected value as 0. The diagnostic mechanism for ADC1 is the same as above, so it will not be described again.

[0062] In this embodiment, the diagnostic signal output by the control circuit is amplified by setting an amplifier circuit. By using an appropriate signal gain, the amplitude of the diagnostic signal is amplified to the required level to ensure that the signal is within a suitable range. At the same time, signal noise and interference can be suppressed, making the signal clearer and more stable. This improves the accuracy of the diagnosis of the conversion circuit and the signal processing quality, and further enhances the reliability and security of the system.

[0063] In one embodiment, please refer to Figures 1-4 The channel sampling circuit 1 includes at least a first sampling circuit and a second sampling circuit, and the external circuit includes at least a first external circuit and a second external circuit.

[0064] The first sampling circuit is connected to the first external circuit, and the second sampling circuit is connected to the second external circuit;

[0065] The first control circuit 4 is used to acquire a first external voltage signal output by the first external circuit through the first conversion circuit 2 and the first sampling circuit, and to acquire a second external voltage signal output by the second external circuit through the first conversion circuit 2 and the second sampling circuit, and to send the first external voltage signal and the second external voltage signal to the second control circuit 5; the second control circuit 5 is used to acquire a third external voltage signal output by the first external circuit through the second conversion circuit 3 and the first sampling circuit, and to acquire a fourth external voltage signal output by the second external circuit through the second conversion circuit 3 and the second sampling circuit 12, and to send the third external voltage signal and the fourth external voltage signal to the first control circuit 4;

[0066] The first control circuit 4 is used to compare a first external voltage signal and a third external voltage signal. When the first external voltage signal and the third external voltage signal meet a preset condition, it generates a first target voltage signal and sends the first target voltage signal to the second control circuit 5. The second control circuit 5 is used to compare the first external voltage signal and the third external voltage signal. When the first external voltage signal and the third external voltage signal meet a preset condition, it generates a second target voltage signal and sends the second target voltage signal to the first control circuit. The first control circuit 4 and the second control circuit 5 are used to compare the first target voltage signal and the second target voltage signal respectively. When the first target voltage signal and the second target voltage signal meet a preset condition, they generate a third target voltage signal.

[0067] The first control circuit 4 compares the second external voltage signal and the fourth external voltage signal. When the second external voltage signal and the fourth external voltage signal meet a preset condition, it generates a fourth target voltage signal and sends the fourth target voltage signal to the second control circuit 5. The second control circuit 5 compares the second external voltage signal and the fourth external voltage signal. When the second external voltage signal and the fourth external voltage signal meet a preset condition, it generates a fifth target voltage signal and sends the fifth target voltage signal to the first control circuit 4. The first control circuit 4 and the second control circuit 5 compare the fourth target voltage signal and the fifth target voltage signal respectively. When the fourth target voltage signal and the fifth target voltage signal meet a preset condition, they generate a sixth target voltage signal.

[0068] The first control circuit 4 and the second control circuit 5 are used to compare the third target voltage signal and the sixth target voltage signal respectively to diagnose whether the output voltage of the first external circuit and the second external circuit is faulty.

[0069] It should be noted that when the first external circuit and the second external circuit are voltage sensors, the output voltage fault of the first external circuit and the second external circuit can refer to a voltage sensor fault, such as a voltage sensor failure.

[0070] In this embodiment, the channel sampling circuit 1 includes at least two sampling circuits (a first sampling circuit and a second sampling circuit), and the external circuit includes at least two external circuits (a first external circuit and a second external circuit). Each sampling circuit is connected to the two external circuits. The first control circuit 4 simultaneously acquires the first external voltage signal output by the first external circuit and the second external voltage signal output by the second external circuit, and sends the first external voltage signal and the second external voltage signal to the second control circuit 5. The second control circuit 5 simultaneously acquires the third external voltage signal output by the first external circuit and the fourth external voltage signal output by the second external circuit, and sends the third external voltage signal and the fourth external voltage signal to the first control circuit 4.

[0071] The first control circuit 4 compares the first external voltage signal and the third external voltage signal to determine if they are within a safe range. If so, it generates and saves the first target voltage signal and simultaneously sends it to the second control circuit 5. If not, it triggers a fault alarm and reports a safe value. The second control circuit 5 compares the first external voltage signal and the third external voltage signal to determine if they are within a safe range. If so, it generates and saves the second target voltage signal and simultaneously sends it to the first control circuit 4. If not, it triggers a fault alarm and reports a safe value. When the first control circuit 4 and the second control circuit 5 receive each other's target voltage signals, they perform interactive comparisons to determine whether the first and second target voltage signals are within a safe range. If so, they generate and save the third target voltage signal; if not, they trigger a fault alarm and report a safe value.

[0072] Similarly, the first control circuit 4 compares the second and fourth external voltage signals to determine if they are within the safe range. If so, it generates and saves the fourth target voltage signal and sends it to the second control circuit 5. If not, it triggers a fault alarm and reports a safe value. The second control circuit 5 compares the second and fourth external voltage signals to determine if they are within the safe range. If so, it generates and saves the fifth target voltage signal and sends it to the first control circuit 4. If not, it triggers a fault alarm and reports a safe value. When the first and second control circuits receive each other's target voltage signals, they perform interactive comparisons to determine if the fourth and fifth target voltage signals are within the safe range. If so, they generate and save the sixth target voltage signal. If not, they trigger a fault alarm and report a safe value.

[0073] Finally, the first control circuit 4 and the second control circuit 5 are used to compare the third target voltage signal and the sixth target voltage signal respectively. When the deviation between the third target voltage signal and the sixth target voltage signal is within the safe range, the voltage acquisition value is determined to be safe, that is, the voltage output by the first external circuit and the second external circuit is normal; otherwise, the voltage acquisition value is determined to be faulty, that is, the voltage output by the first external circuit and the second external circuit is abnormal, and the fault is reported.

[0074] In this embodiment, the voltage acquisition circuit 100, by setting at least two sampling circuits and two external circuits, can cross-compare the output voltages of the two external circuits to diagnose whether the output voltages of the two external circuits have malfunctioned. This single-module approach enables the diagnosis of the output voltages of the two external circuits, ensuring the safety and reliability of voltage acquisition, reducing complex module redundancy design, and improving the functional safety level. It solves the problems of complex redundancy design and low functional safety level in existing analog voltage acquisition circuit modules. Through this scheme, when using 1oo2 evaluation, the correctness of the output voltages of the two external sensors can be diagnosed by comparing the two channels, achieving a safety level of SIL 3 / PLe / Cat.4. This expands the functionality of the voltage acquisition circuit 100 and further enhances its safety level.

[0075] It is understood that channel sampling circuit 1 can also include two or more sampling circuits, such as four sampling circuits. Correspondingly, the external circuits can also include two or more external circuits, such as four external circuits, with each sampling circuit connected to all four external circuits. This scheme allows for comparison and diagnosis of the output voltages of the four external circuits to determine if a fault has occurred. The specific diagnostic process is consistent with the two-channel case described above and will not be repeated here. Of course, in other embodiments, the number of channel sampling circuits 1 and the number of external circuits can be determined according to actual conditions; this embodiment does not limit this.

[0076] It should be noted that when there are two or more channel sampling circuits 1 and external circuits, the diagnosis of whether the voltage acquisition circuit 100 itself is faulty and the diagnosis of whether the conversion circuit is faulty can be realized for each sampling circuit and external circuit as described in the previous embodiment. The diagnosis process and principle have been described in detail in the previous embodiment, and will not be repeated in this embodiment.

[0077] In one embodiment, please refer to Figure 1 The channel sampling circuit 1 includes a sampling resistor 13, a third switching circuit 14, and a fourth switching circuit 15;

[0078] The sampling resistor 13 is connected to the third switching circuit 14, the fourth switching circuit 15 and the external circuit. The third switching circuit 14 is connected to the first conversion circuit 2 and the fourth switching circuit 15 is connected to the second conversion circuit 3.

[0079] In this embodiment, the third switch circuit 14 and the fourth switch circuit 15 can be analog switches. The selection of the sampling circuit 13 and the analog switches can be determined according to actual needs, and this embodiment does not limit this.

[0080] In this embodiment, the sampling channel circuit 1 is constructed using sampling circuit 13, third switch circuit 14, and fourth switch circuit 15. The circuit structure is simple and the cost is low.

[0081] In one embodiment, please refer to Figure 1 The sampling resistor 13 includes a first sampling resistor 131 and a second sampling resistor 132 connected in parallel; the first sampling resistor 131 is connected to the third switching circuit 14, the fourth switching circuit 15 and the external circuit, and the second sampling resistor 132 is connected to the third switching circuit 14, the fourth switching circuit 15 and the external circuit.

[0082] In this embodiment, the sampling resistors 131 and 132 are connected in parallel to achieve redundancy of the sampling resistors. When one of the sampling resistors fails, it will not affect the function of the channel sampling circuit 1, thereby improving the redundancy capability and security of the channel sampling circuit 1.

[0083] In one embodiment, please refer to Figure 1 The channel sampling circuit 1 also includes a protection circuit 105; the protection circuit 105 is connected to the sampling resistor 13, the third switching circuit 14 and the fourth switching circuit 15.

[0084] In this embodiment, the protection circuit monitors and limits the voltage and current entering the sampling circuit to prevent overload damage to circuit components. In practical applications, the protection circuit typically uses various protective components, such as transient voltage suppressors (TVS), fuses, diodes, etc. These components can respond quickly when the voltage or current exceeds a safe threshold. In other embodiments, the protection circuit 105 can also be a circuit with protective functions built from discrete components; this embodiment does not limit this. By setting the protection circuit 105 to prevent the voltage from exceeding the rated value of the device or circuit, damage caused by overvoltage is avoided. By detecting the current and cutting off the power supply when it exceeds a set threshold, the protection circuit can prevent overcurrent from damaging the device. Furthermore, the protection circuit can quickly cut off the power supply when a short circuit is detected to prevent circuit components from burning out due to a short circuit.

[0085] In this embodiment, by setting up a protection circuit, the risks of overvoltage and short circuit can be effectively avoided, the reliability and stability of the voltage acquisition circuit 100 can be improved, the service life of the circuit can be extended, and its safe and stable operation under various working conditions can be ensured.

[0086] This invention provides a voltage acquisition device, which includes a voltage acquisition circuit as described in the above embodiments. Since the voltage acquisition circuit according to the above embodiments of this invention has the above-mentioned technical effects, the voltage acquisition device according to the embodiments of this invention also has corresponding technical effects. The voltage acquisition circuit supports single / dual channel voltage acquisition, thereby realizing the sampling of the output voltage terminal of the external circuit, reducing complex module redundancy design, and improving the functional safety level.

[0087] This invention provides a voltage acquisition system, comprising a host device and at least one voltage acquisition device as described in the above embodiments, wherein the host device and the voltage acquisition device are connected via a communication bus. Since the voltage acquisition device according to the above embodiments of this invention has the aforementioned technical effects, the voltage acquisition system according to the embodiments of this invention also has corresponding technical effects. By supporting single / dual-channel voltage acquisition through the voltage acquisition circuit, it enables sampling of the output voltage terminal of external circuits, reduces complex module redundancy design, and improves the functional safety level.

[0088] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0089] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0090] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A voltage acquisition circuit, characterized in that, The voltage acquisition circuit includes a channel sampling circuit, a first conversion circuit, a second conversion circuit, a first control circuit, a second control circuit, and a cross-diagnosis circuit; The channel sampling circuit is connected to an external circuit, the first conversion circuit and the second conversion circuit are connected to the channel sampling circuit, the first control circuit is connected to the second control circuit and the first conversion circuit, the second control circuit is connected to the second conversion circuit, and the cross-diagnosis circuit is connected to the first conversion circuit, the second conversion circuit, the first control circuit and the second control circuit. The channel sampling circuit is used to acquire the external voltage signal output by the external circuit. The first conversion circuit is used to convert the external voltage signal into a first voltage signal. The second conversion circuit is used to convert the external voltage signal into a second voltage signal. The first control circuit is used to receive the first voltage signal and send the first voltage signal to the second control circuit. The second control circuit is used to receive the second voltage signal and send the second voltage signal to the first control circuit. The first control circuit and the second control circuit are used to compare the first voltage signal and the second voltage signal respectively to diagnose whether the voltage acquisition circuit is faulty. The second control circuit sends a first diagnostic signal to the first control circuit through the cross-diagnostic circuit and the first conversion circuit, and the first control circuit diagnoses whether the first conversion circuit is faulty based on the first diagnostic signal; the first control circuit sends a second diagnostic signal to the second control circuit through the cross-diagnostic circuit and the second conversion circuit, and the second control circuit diagnoses whether the second conversion circuit is faulty based on the second diagnostic signal.

2. The voltage acquisition circuit according to claim 1, characterized in that, The cross-diagnosis circuit includes a first switching circuit and a second switching circuit. The first switching circuit is connected to the first conversion circuit and the second control circuit, and the second switching circuit is connected to the second conversion circuit and the first control circuit. The second control circuit sends the first diagnostic signal to the first control circuit through the first switching circuit and the first conversion circuit. The first control circuit diagnoses whether the first conversion circuit has malfunctioned based on the first diagnostic signal. The first control circuit sends the second diagnostic signal to the first control circuit through the second switching circuit and the second conversion circuit. The second control circuit diagnoses whether the second conversion circuit has malfunctioned based on the second diagnostic signal.

3. The voltage acquisition circuit according to claim 2, characterized in that, The cross-diagnosis circuit also includes a first amplifier circuit and a second amplifier circuit. The first amplifier circuit is connected to the first control circuit and the second switch circuit, and the second amplifier circuit is connected to the second control circuit and the first switch circuit. The second control circuit sends the first diagnostic signal to the first control circuit through the second amplifier circuit, the first switch circuit, and the first conversion circuit. The first control circuit diagnoses whether the first conversion circuit has malfunctioned based on the first diagnostic signal. The first control circuit sends the second diagnostic signal to the second control circuit through the first amplifier circuit, the second switch circuit, and the second conversion circuit. The second control circuit diagnoses whether the second conversion circuit has malfunctioned based on the second diagnostic signal.

4. The voltage acquisition circuit according to claim 1, characterized in that, The channel sampling circuit includes at least a first sampling circuit and a second sampling circuit, and the external circuit includes at least a first external circuit and a second external circuit. The first sampling circuit is connected to the first external circuit, and the second sampling circuit is connected to the second external circuit; The first control circuit is used to acquire a first external voltage signal output by the first external circuit through the first conversion circuit and the first sampling circuit, and to acquire a second external voltage signal output by the second external circuit through the first conversion circuit and the second sampling circuit, and to send the first external voltage signal and the second external voltage signal to the second control circuit. The second control circuit is used to acquire a third external voltage signal output by the first external circuit through the second conversion circuit and the first sampling circuit, and to acquire a fourth external voltage signal output by the second external circuit through the second conversion circuit and the second sampling circuit, and to send the third external voltage signal and the fourth external voltage signal to the first control circuit. The first control circuit is used to compare the first external voltage signal and the third external voltage signal. When the first external voltage signal and the third external voltage signal meet a preset condition, a first target voltage signal is generated and the first target voltage signal is sent to the second control circuit. The second control circuit is used to compare the first external voltage signal and the third external voltage signal. When the first external voltage signal and the third external voltage signal meet a preset condition, a second target voltage signal is generated and sent to the first control circuit. The first control circuit and the second control circuit are used to compare the first target voltage signal and the second target voltage signal respectively, and generate a third target voltage signal when the first target voltage signal and the second target voltage signal meet a preset condition; The first control circuit is used to compare the second external voltage signal and the fourth external voltage signal. When the second external voltage signal and the fourth external voltage signal meet a preset condition, a fourth target voltage signal is generated and the fourth target voltage signal is sent to the second control circuit. The second control circuit is used to compare the second external voltage signal and the fourth external voltage signal. When the second external voltage signal and the fourth external voltage signal meet a preset condition, a fifth target voltage signal is generated and the fifth target voltage signal is sent to the first control circuit. The first control circuit and the second control circuit are used to compare the fourth target voltage signal and the fifth target voltage signal respectively, and generate a sixth target voltage signal when the fourth target voltage signal and the fifth target voltage signal meet a preset condition; The first control circuit and the second control circuit are used to compare the third target voltage signal and the sixth target voltage signal respectively to diagnose whether the output voltage of the first external circuit and the second external circuit is faulty.

5. The voltage acquisition circuit according to claim 1, characterized in that, The channel sampling circuit includes a sampling resistor, a third switching circuit, and a fourth switching circuit; The sampling resistor is connected to the third switching circuit, the fourth switching circuit, and the external circuit. The third switching circuit is connected to the first conversion circuit, and the fourth switching circuit is connected to the second conversion circuit.

6. The voltage acquisition circuit according to claim 5, characterized in that, The sampling resistor includes a first sampling resistor and a second sampling resistor connected in parallel; the first sampling resistor is connected to the third switching circuit, the fourth switching circuit and the external circuit, and the second sampling resistor is connected to the third switching circuit, the fourth switching circuit and the external circuit.

7. The voltage acquisition circuit according to claim 5 or 6, characterized in that, The channel sampling circuit further includes a protection circuit; the protection circuit is connected to the sampling resistor, the third switching circuit, and the fourth switching circuit.

8. The voltage acquisition circuit according to any one of claims 1-7, characterized in that, The first conversion circuit and the second conversion circuit are analog-to-digital converters.

9. A voltage acquisition device, characterized in that, The voltage acquisition device includes the voltage acquisition circuit as described in any one of claims 1-8.

10. A voltage acquisition system, characterized in that, The voltage acquisition system includes a host device and at least one voltage acquisition device as described in claim 9, wherein the host device and the voltage acquisition device are connected via a communication bus.

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