A redundant power supply switch diagnostic circuit

Abstract

This utility model discloses a redundant power supply switch diagnostic circuit, including a first signal circuit, a second signal circuit, and a third signal circuit. The first signal circuit and the third signal circuit are electrically connected, and the second signal circuit and the third signal circuit are also electrically connected. Detection points are provided on the first, second, and third signal circuits for open-circuit and short-circuit diagnosis. This utility model provides a redundant power supply switch diagnostic circuit that, by setting detection points in the first, second, and third signal circuits, enables the detection of wiring harness loss and open-circuit and short-circuit diagnosis of all MOSFETs in the redundant power supply switch during the system initialization phase. The principle is simple, the reliability is high, and it meets the ASIL D functional safety requirements of the braking system.

Description

Technical Field

[0001] This utility model belongs to the field of automotive electronic controller technology, specifically relating to a redundant power supply switch diagnostic circuit. Background Technology

[0002] With the advancement of technology, the functional safety requirements for the braking system of automobile chassis are becoming increasingly stringent. Among these requirements, redundant power supply and power-on initialization diagnostics are necessary choices to improve functional safety, and we have increasingly higher requirements for the stability, reliability, and comprehensiveness of the diagnostics.

[0003] Taking the One-Box braking system as an example, One-Box is an integrated electro-hydraulic braking system. Unlike current passenger car braking technologies, this system does not require a vacuum source to provide braking assistance. The One-Box system employs a "brake-by-wire" design, meaning that during normal braking, the pedal force and displacement when the driver presses the brake pedal are connected to a pedal feel simulator. There is no hydraulic connection between the brake pedal and the wheel cylinders; that is, pressing the brake pedal does not directly create pressure in the wheel cylinders (except in backup mode). In hybrid / pure electric vehicles, One-Box can achieve regenerative braking, coordinating the braking force composed of hydraulic pressure and motor drag force.

[0004] The current mainstream solution can only perform open / short circuit diagnosis on a single loop switch (S1, S2, S3) formed by two switching MOSFETs, and cannot accurately diagnose open / short circuits on a single MOSFET. Utility Model Content

[0005] The purpose of this invention is to propose a redundant power supply switch diagnostic circuit to solve the problem in related technologies that cannot accurately diagnose open and short circuits of individual MOSFETs.

[0006] Therefore, this utility model provides a redundant power supply switch diagnostic circuit, including: a first signal circuit, a second signal circuit and a third signal circuit, wherein the first signal circuit is electrically connected to the third signal circuit, the second signal circuit is electrically connected to the third signal circuit, and detection points are provided on the first signal circuit, the second signal circuit and the third signal circuit for open and short circuit diagnosis.

[0007] Preferably, the first signal circuit includes an eighth capacitor, a sixth MOSFET, a fifth resistor, a fourth diode, and a fifth MOSFET. A first power supply is connected between the eighth capacitor and the sixth MOSFET. The eighth capacitor is grounded. The eighth capacitor is electrically connected to the sixth MOSFET. The sixth MOSFET is electrically connected to the fifth MOSFET. The fifth resistor and the fourth diode are disposed between the sixth MOSFET and the fifth MOSFET. The fifth MOSFET is electrically connected to the third signal circuit. A thirteenth capacitor is electrically connected between the fifth MOSFET and the third signal circuit.

[0008] Preferably, the sixth MOSFET, the fifth resistor, the fourth diode, and the fifth MOSFET are electrically connected to the sixth resistor, and the sixth resistor is connected to the first signal output interface.

[0009] Preferably, a first detection point is provided between the eighth capacitor and the sixth MOS transistor, a third detection point is provided between the sixth MOS transistor and the fifth MOS transistor, and a fifth detection point is provided between the thirteenth capacitor and the fifth MOS transistor.

[0010] Preferably, the second signal circuit includes a fourth capacitor, a first MOSFET, a first resistor, a first diode, and a second MOSFET. A second power supply is connected between the fourth capacitor and the first MOSFET. The fourth capacitor is grounded. The fourth capacitor is electrically connected to the first MOSFET. The first MOSFET is electrically connected to the second MOSFET. The first resistor and the second diode are disposed between the first MOSFET and the second MOSFET. The second MOSFET is electrically connected to the third signal circuit. A seventh capacitor is electrically connected between the second MOSFET and the third signal circuit.

[0011] Preferably, the first MOSFET, the first resistor, the first diode, and the second MOSFET are electrically connected to a fourth resistor, and the fourth resistor is connected to a second signal output interface.

[0012] Preferably, a second detection point is provided between the fourth capacitor and the sixth MOS transistor, a fourth detection point is provided between the first MOS transistor and the second MOS transistor, and a sixth detection point is provided between the seventh capacitor and the second MOS transistor.

[0013] Preferably, the third signal circuit includes a third MOSFET, a third resistor, a third diode, and a fourth MOSFET, wherein the third MOSFET is electrically connected to the fourth MOSFET, and the third resistor and the third diode are located between the third MOSFET and the fourth MOSFET.

[0014] Preferably, the third MOSFET, the third resistor, the third diode, and the fourth MOSFET are connected to a second resistor, and the second resistor is connected to a third signal output interface.

[0015] Preferably, a seventh detection point is provided between the third resistor and the third diode.

[0016] Beneficial effects:

[0017] 1. This utility model provides a redundant power supply switch diagnostic circuit. By setting detection points in the first signal circuit, the second signal circuit and the third signal circuit, it can detect the loss of wiring harness and the open and short circuit of all MOSFETs of the redundant power supply switch during the system initialization stage. The principle is simple, the reliability is high, and it meets the ASIL D functional safety requirements of the braking system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The circuit diagram is shown in Embodiment 1 of the redundant power supply switch diagnostic circuit provided by this utility model.

[0020] In the diagram: 1 - First power supply, 2 - First signal output interface, 3 - First detection point, 4 - Third detection point, 5 - Fifth detection point, 6 - Second power supply, 7 - Second signal output interface, 8 - Second detection point, 9 - Fourth detection point, 10 - Sixth detection point, 11 - Third signal output interface, 12 - Seventh detection point, D1 - First diode, D2 - Second diode, D3 - Third diode, D4 ​​- Fourth diode, C1 - First capacitor, C2 - Second capacitor, C3 - Third capacitor, C4 - Fourth capacitor, C 5 - Fifth capacitor, C6 - Sixth capacitor, C7 - Seventh capacitor, C8 - Eighth capacitor, C9 - Ninth capacitor, C10 - Tenth capacitor, C11 - Eleventh capacitor, C12 - Twelfth capacitor, C13 - Thirteenth capacitor, R1 - First resistor, R2 - Second resistor, R3 - Third resistor, R4 - Fourth resistor, Q1 - First MOSFET, Q2 - Second MOSFET, Q3 - Third MOSFET, Q4 - Fourth MOSFET, Q1 - Fifth MOSFET, Q2 - Sixth MOSFET, L1 - First inductor. Detailed Implementation

[0021] The following detailed description of preferred embodiments of the present invention, along with the included examples, will make the content of the present invention more readily understood. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of any conflict, the definitions in this specification shall prevail.

[0022] Example 1:

[0023] Provided such as Figure 1 The redundant power supply switch diagnostic circuit shown includes: a first signal circuit, a second signal circuit, and a third signal circuit. The first signal circuit and the third signal circuit are electrically connected, and the second signal circuit and the third signal circuit are electrically connected. Detection points are provided on the first signal circuit, the second signal circuit, and the third signal circuit for open and short circuit diagnosis.

[0024] The first signal circuit includes an eighth capacitor C8, a sixth MOSFET Q6, a fifth resistor R5, a fourth diode D4, and a fifth MOSFET Q5. A first power supply 1 is connected between the eighth capacitor C8 and the sixth MOSFET Q6. The eighth capacitor C8 is grounded. The eighth capacitor C8 is electrically connected to the sixth MOSFET Q6. The sixth MOSFET Q6 is electrically connected to the fifth MOSFET Q5. The fifth resistor R5 and the fourth diode D4 are located between the sixth MOSFET Q6 and the fifth MOSFET Q5. The fifth MOSFET Q5 is electrically connected to the third signal circuit. A thirteenth capacitor C13 is electrically connected between the fifth MOSFET Q5 and the third signal circuit.

[0025] The sixth MOSFET Q6, the fifth resistor R5, the fourth diode D4, and the fifth MOSFET Q5 are electrically connected to the sixth resistor R6, which is connected to the first signal output interface 2. The first signal output interface 2 is used to control the switch S1.

[0026] A first detection point 2 is located between the eighth capacitor C8 and the sixth MOSFET Q6; a third detection point 4 is located between the sixth MOSFET Q6 and the fifth MOSFET Q5; and a fifth detection point 5 is located between the thirteenth capacitor C13 and the fifth MOSFET Q5. The first detection point 2 is named KL30_1_FBK_A, the third detection point 4 is named KL30_V_SW_FBK_A, and the fifth detection point 5 is named KL30_V_FBK_A.

[0027] A ninth capacitor C9 and a tenth capacitor C10 are provided between the eighth capacitor C8 and the sixth MOSFET Q6. The ninth capacitor C9 and the tenth capacitor C10 are electrically connected and grounded.

[0028] The second signal circuit includes a fourth capacitor C4, a first MOSFET Q1, a first resistor R1, a first diode D1, and a second MOSFET Q2. A second power supply 6 is connected between the fourth capacitor C4 and the first MOSFET Q1. The fourth capacitor C4 is grounded. The fourth capacitor C4 is electrically connected to the first MOSFET Q1. The first MOSFET Q1 is electrically connected to the second MOSFET Q2. The first resistor R1 and the first diode D1 are located between the first MOSFET Q1 and the second MOSFET Q2. The second MOSFET Q2 is electrically connected to the third signal circuit. A seventh capacitor C7 is electrically connected between the second MOSFET Q2 and the third signal circuit.

[0029] The first MOSFET Q1, the first resistor R1, the first diode D1, and the second MOSFET Q2 are electrically connected to a fourth resistor R4. The fourth resistor R4 is connected to a second signal output interface 7. The second signal output interface 7 is used to control the switch S2.

[0030] A second detection point 8 is located between the fourth capacitor C4 and the sixth MOSFET Q6; a fourth detection point 9 is located between the first MOSFET Q1 and the second MOSFET Q2; and a sixth detection point 10 is located between the seventh capacitor C7 and the second MOSFET Q2. The first detection point 2 is named KL30_2_FBK_A, the third detection point 4 is named KL30_M_SW_FBK_A, and the fifth detection point 5 is named KL30_M_FBK_A.

[0031] A first capacitor C1 and a fifth capacitor C5 are provided between the fourth capacitor C4 and the first MOSFET Q1. The first capacitor C1 and the fifth capacitor C5 are electrically connected and grounded.

[0032] A sixth capacitor C6 is placed between the seventh capacitor C7 and the second MOSFET Q2, and the sixth capacitor C6 is grounded.

[0033] The seventh capacitor C7 is connected to the second diode D2, the first inductor L1, the second capacitor C2, and the third capacitor C3. The second diode D2, the second capacitor C2, and the third capacitor C3 are grounded.

[0034] The third signal circuit includes a third MOSFET Q3, a third resistor R3, a third diode D3, and a fourth MOSFET Q4. The third MOSFET Q3 and the fourth MOSFET Q4 are electrically connected, and the third resistor R3 and the third diode D3 are located between the third MOSFET Q3 and the fourth MOSFET Q4.

[0035] The third MOSFET Q3, the third resistor R3, the third diode D3, and the fourth MOSFET Q4 are connected to the second resistor R2, which is connected to the third signal output interface 11. The third signal output interface 11 is used to control the switch S3.

[0036] A seventh detection point 12 is set between the third resistor R3 and the third diode D3. The seventh detection point 12 is named KL30_MERGE_FBK_A.

[0037] Working principle:

[0038] 1. Upon power-up, the voltage thresholds of the first detection point 3KL30_1_FBK_A and the second detection point 4KL30_2_FBK_A are sampled to determine whether the two power supply harnesses are missing. If the sampled value of KL30_2_FBK_A is lower than the threshold, the power supply harness KL30_2 is missing. Redundant power supply is started by turning on Q3 and Q4 MOS. At the same time, the voltage thresholds of KL30_M_FBK_A and KL30_V_FBK_A are judged to determine whether there is a short circuit or open circuit in switch S1 and switch S3.

[0039] 2: If the sampled value of KL30_1_FBK_A is lower than the threshold, the power supply harness KL30_1 is lost; redundant power supply is started by turning on Q3 and Q4 MOS, and at the same time, the voltage thresholds of KL30_M_FBK_A and KL30_V_FBK_A are judged to determine whether there is a short circuit or open circuit in switch S2 and switch S3.

[0040] 3: If the power-on diagnostics show that KL30_1_FBK_A and KL30_2_FBK_A are both within the correct threshold range, then the two power supplies are considered to be functioning normally. The open / short circuit status of the six switching MOSFETs (Q1, Q2, Q3, Q4, Q5, and Q6) is determined by the voltage range sampled by the seven ADCs (KL30_2_FBK_A, KL30_M_SW_FBK_A, KL30_M_FBK_A, KL30_MERGE_FBK_A, KL30_1_FBK_A, KL30_V_SW_FBK_A, and KL30_V_FBK_A), achieving a higher diagnostic coverage rate.

[0041] like Figure 1 As shown, KL30_M_SW_EN, KL30_MERGE, and KL30_V_SW_EN are the enable signals for switches S1, S2, and S3, respectively. HIGH indicates that these three switches are on, and LOW indicates that they are off. KL30_2_FBK_A, KL30_M_SW_FBK_A, KL30_M_FBK_A, KL30_MERGE_FBK_A, KL30_1_FBK_A, KL30_V_SW_FBK_A, and KL30_V_FBK_A are the monitored voltage values. A Class A fault is defined as a non-critical fault; when a Class A fault occurs, the system activates redundant power supply. A Class B fault is defined as a critical fault; when a Class B fault occurs, the ECU stops working.

[0042] Diagnostic steps:

[0043] S1: Upon power-up, monitor the voltage status of the second power supply 6KL30_2.

[0044] If the sampled value is less than 6.5V, it is determined that the power harness of the second power supply 6KL30_2 is missing. At this time, the software marks it as a Class A fault and continues to execute the redundancy power supply diagnosis process of the first power supply 1KL30_1 according to Plan B.

[0045] If the sampled value of the second power supply 6KL30_2 is greater than or equal to 6.5V, it is determined that the power supply harness of the second power supply 6KL30_2 is normal, and then the voltage of KL30_1 is checked; if the sampled value is less than 6.5V, it is determined that the power supply harness of the first power supply 1KL30_1 is missing; at this time, the software marks: Class A fault flag, and continues to execute the redundant power supply diagnosis process of the second power supply 6KL30_2 according to PlanC.

[0046] If the voltage sampling of the first power supply 1KL30_1 is greater than or equal to 6.5V, then it is determined that the wiring harnesses of the first power supply 1KL30_1 and the second power supply 6KL30_2 are normal, and the subsequent power-on diagnostic process is carried out according to Plan A.

[0047] The signals are shown in the table below:

[0048]

[0049] The determination methods are shown in the table below:

[0050]

[0051] S2: When the second power supply 6KL30_2 harness is lost, press PlanB to execute the first power supply 1 KL30_1 redundant power supply diagnostic process.

[0052] The diagnostic steps are as follows:

[0053]

[0054] The determination methods are shown in the table below:

[0055]

[0056] S3: When the first power supply 1KL30_1 harness is lost, execute the second power supply 6KL30_2 redundant power supply diagnostic process according to PlanC.

[0057] The diagnostic steps are as follows:

[0058]

[0059] The determination method is as follows:

[0060]

[0061] S4: The wiring harnesses for the first power supply 1KL30_1 and the second power supply 6KL30_2 are both normal. Proceed with the subsequent power-on diagnostic process according to Plan A.

[0062] The diagnostic steps are shown in the table below:

[0063]

[0064] The determination methods are shown in the table below:

[0065]

[0066] This embodiment uses different power-on diagnostic logics by judging the state of the wiring harness during the power-on initialization phase; by adding a sampling circuit between the redundant power supply switch MOSFETs, the sampling logic is used to judge whether the six redundant power supply MOSFETs are open or short-circuited; for the open or short circuit of the redundant switch, the fault level is defined, and the system judges the fault level to determine whether to perform redundant power supply or stop working.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A redundant power supply switch diagnostic circuit, comprising: include: The circuit comprises a first signal circuit, a second signal circuit, and a third signal circuit. The first signal circuit is electrically connected to the third signal circuit, and the second signal circuit is electrically connected to the third signal circuit. Each of the first signal circuit, the second signal circuit, and the third signal circuit has a detection point for open / short circuit diagnosis.

2. A redundant supply switch diagnostic circuit according to claim 1, wherein, The first signal circuit includes an eighth capacitor, a sixth MOSFET, a fifth resistor, a fourth diode, and a fifth MOSFET. A first power supply is connected between the eighth capacitor and the sixth MOSFET. The eighth capacitor is grounded. The eighth capacitor is electrically connected to the sixth MOSFET. The sixth MOSFET is electrically connected to the fifth MOSFET. The fifth resistor and the fourth diode are disposed between the sixth MOSFET and the fifth MOSFET. The fifth MOSFET is electrically connected to the third signal circuit. A thirteenth capacitor is electrically connected between the fifth MOSFET and the third signal circuit.

3. A redundant supply switch diagnostic circuit according to claim 2, wherein, The sixth MOSFET, the fifth resistor, the fourth diode, and the fifth MOSFET are electrically connected to the sixth resistor, and the sixth resistor is connected to the first signal output interface.

4. A redundant power supply switch diagnostic circuit according to claim 2, wherein, A first detection point is provided between the eighth capacitor and the sixth MOS transistor, a third detection point is provided between the sixth MOS transistor and the fifth MOS transistor, and a fifth detection point is provided between the thirteenth capacitor and the fifth MOS transistor.

5. A redundant power supply switch diagnostic circuit according to claim 1, wherein, The second signal circuit includes a fourth capacitor, a first MOSFET, a first resistor, a first diode, and a second MOSFET. A second power supply is connected between the fourth capacitor and the first MOSFET. The fourth capacitor is grounded. The fourth capacitor is electrically connected to the first MOSFET. The first MOSFET is electrically connected to the second MOSFET. The first resistor and the second diode are disposed between the first MOSFET and the second MOSFET. The second MOSFET is electrically connected to the third signal circuit. A seventh capacitor is electrically connected between the second MOSFET and the third signal circuit.

6. A redundant supply switch diagnostic circuit according to claim 5, wherein, The first MOSFET, the first resistor, the first diode, and the second MOSFET are electrically connected to a fourth resistor, which is connected to a second signal output interface.

7. A redundant power supply switch diagnostic circuit according to claim 5, wherein, A second detection point is provided between the fourth capacitor and the sixth MOSFET, a fourth detection point is provided between the first MOSFET and the second MOSFET, and a sixth detection point is provided between the seventh capacitor and the second MOSFET.

8. A redundant power supply switch diagnostic circuit according to claim 1, wherein, The third signal circuit includes a third MOSFET, a third resistor, a third diode, and a fourth MOSFET. The third MOSFET is electrically connected to the fourth MOSFET, and the third resistor and the third diode are located between the third MOSFET and the fourth MOSFET.

9. A redundant supply switch diagnostic circuit according to claim 8, wherein, The third MOSFET, the third resistor, the third diode, and the fourth MOSFET are connected to a second resistor, which is connected to a third signal output interface.

10. A redundant supply switch diagnostic circuit according to claim 9, wherein, A seventh detection point is provided between the third resistor and the third diode.

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