Safe turn-off control circuit

Abstract

The utility model belongs to the technical field of automobile electric control systems, and particularly relates to a safe turn-off control circuit, which comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a triode T1, a triode T2 and a connection relation thereof. According to the utility model, a control path is provided between the system state monitoring unit and the function driving output unit; effective state feedback is provided to the system function control unit, and after the system function control unit still can operate or resumes operation from an abnormal state, a safe turn-off control state can be obtained. The input voltage and current requirements of different function driving output units are met, particularly, multi-path driving output control is provided at the same time, it is guaranteed that control signals are relatively independent, and input faults of any path of function driving output unit cannot cause input anomalies of other function driving output units.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile electronic control systems, and in particular to a safety shutdown control circuit, which is applied to an ECU (Electronic Control Unit) electronic controller with specified requirements for functional safety. Background Art

[0002] In automotive electronic control systems, according to the system fail-safe state requirements, when the ECU identifies a functional anomaly, it must ensure that the ECU's output functions enter the expected, controllable, safe state. To this end, an ECU with safety requirements generally includes at least three components: a system function control unit, a system status monitoring unit, and a function drive output unit.

[0003] During normal operation, the system function control unit sends control instructions to the function drive output unit to implement the system function; when the internal and external status of the system is abnormal, the system status monitoring unit detects the abnormality and outputs a shutdown control instruction to the function drive output unit to shut down the output, thereby putting the system into a controllable and safe state.

[0004] Therefore, the current selection of matching system status monitoring unit chips, system function control unit chips and function drive output units to build safety shutdown control has poor flexibility; in addition, the system status monitoring unit has limited output shutdown control signal driving capabilities, making it difficult to meet multi-channel drive output control requirements. Utility Model Content

[0005] The purpose of the utility model is to solve the technical problems existing in the background technology, and to this end, a safety shutdown control circuit is provided.

[0006] In order to achieve the above purpose, the technical solutions adopted by this utility model are as follows:

[0007] A safety shutdown control circuit includes a resistor R1, a resistor R2, a resistor R6, a resistor R7 and a transistor T2;

[0008] One end of the resistor R1 is connected to the output end of the system function control unit, and the other end of the resistor R1 is connected to the input end of the function drive output unit;

[0009] One end of the resistor R2 is connected to the output end of the system status monitoring unit, and the other end of the resistor R2 is connected to the input end of the system function control unit;

[0010] One end of the resistor R6 is directly or indirectly connected to the output end of the system status monitoring unit, and the other end of the resistor R6 is connected to the base of the transistor T2;

[0011] One end of the resistor R7 is connected to the base of the transistor T2, and the other end of the resistor R7 is connected to the power supply GND;

[0012] The collector of the transistor T2 is connected to the function drive output unit; the emitter of the transistor T2 is connected to the power supply GND.

[0013] The following is a technical solution further defined by the circuit in the present invention: when the resistor R6 is indirectly connected to the output end of the system status monitoring unit, a resistor R3, a resistor R4 and a transistor T1 are provided between the resistor R6 and the output end of the system status monitoring unit;

[0014] One end of the resistor R3 is connected to the signal logic power supply VCC, and the other end of the resistor R3 is connected to the output end of the system status monitoring unit;

[0015] One end of the resistor R4 is connected to the base of the transistor T1, and the other end of the resistor R4 is connected to the output end of the system status monitoring unit;

[0016] The emitter of the transistor T1 is connected to the signal logic power supply VCC, and the collector of the transistor T1 is connected to one end of the resistor R6.

[0017] The following is a technical solution further defined by the circuit in the present invention, which further includes a resistor R5, one end of which is connected to the base of the transistor T1, and the other end of which is connected to the signal logic power supply VCC.

[0018] The following is a technical solution further defined by the circuit in the present invention. When a direct connection is made between the resistor R6 and the output end of the system status monitoring unit, the output end of the system status monitoring unit is connected to one end of the resistor R3, and the other end of the resistor R3 is connected to the power supply GND.

[0019] The following is a technical solution further defined by the circuit in the present invention, wherein the transistor T2 is configured as an NPN transistor.

[0020] The following is a technical solution further defined by the circuit in the present invention, wherein the transistor T1 is configured as a PNP transistor.

[0021] Compared with the prior art, the present invention has the following technical effects:

[0022] The utility model is provided with a safety shutdown control circuit, which provides a control path between the system status monitoring unit and the function drive output unit, and ensures that the control instructions of the system status monitoring unit effectively act on the function drive output unit when the system function control unit is abnormal; secondly, the safety shutdown control circuit provides effective status feedback to the system function control unit while shutting down the drive output, and the safety shutdown control status can be obtained when the system function control unit can still operate or recover from the abnormality; finally, the safety shutdown control circuit meets the input voltage and current requirements of different function drive output units, especially provides multi-channel drive output control at the same time, and ensures that the control signals are relatively independent, so that the input failure of any one function drive output unit will not cause the input abnormality of other function drive output units.

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 It is a connection relationship diagram of the application system after the utility model is applied;

[0026] Figure 2 This is a connection diagram of an application system including a single-channel safety shutdown control circuit in Example 1 of the present utility model;

[0027] Figure 3 This is a connection diagram of an application system including a multi-channel safety shutdown control circuit in Example 1 of the present utility model;

[0028] Figure 4 This is a connection diagram of an application system including a single-channel safety shutdown control circuit in Example 2 of the present utility model;

[0029] Figure 5 This is a connection diagram of an application system including a multi-path safety shutdown control circuit in Example 2 of the present utility model. DETAILED DESCRIPTION

[0030] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] In the embodiments of the present invention, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to electrical connection, direct connection, indirect connection through an intermediate medium, internal communication between two components, or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0032] Example 1

[0033] like Figure 1 、 2 As shown in FIG3 , a safety shutdown control circuit is provided, including a resistor R1 , a resistor R2 , a resistor R3 , a resistor R4 , a resistor R5 , a resistor R6 , a resistor R7 , a transistor T1 , and a transistor T2 .

[0034] One end of the resistor R1 is electrically connected to the enable / disable control output end of the system function control unit, and the other end of the resistor R1 is electrically connected to the enable / disable control input end of the function drive output unit.

[0035] One end of the resistor R2 is electrically connected to the shutdown control output end of the system state monitoring unit, and the other end of the resistor R2 is connected to the state feedback input end of the system function control unit.

[0036] The system status monitoring unit is electrically connected to the system function control unit, so that the system status monitoring unit can monitor the status of the system.

[0037] One end of the resistor R3 is electrically connected to the signal logic power supply VCC, and the other end of the resistor R3 is electrically connected to the shutdown control output end of the system status monitoring unit.

[0038] One end of the resistor R4 is electrically connected to the base of the PNP transistor T1 , and the other end of the resistor R4 is electrically connected to the shutdown control output end of the system status monitoring unit.

[0039] One end of the resistor R5 is electrically connected to the base of the PNP transistor T1 , and the other end of the resistor R5 is electrically connected to the signal logic power supply VCC.

[0040] The emitter of the PNP transistor T1 is electrically connected to the signal logic power supply VCC, and the collector of the PNP transistor T1 is electrically connected to one end of the resistor R6.

[0041] One end of the resistor R6 is electrically connected to the collector of the PNP transistor T1 , and the other end of the resistor R6 is electrically connected to the base of the NPN transistor T2 .

[0042] One end of the resistor R7 is electrically connected to the base of the NPN transistor T2 , and the other end of the resistor R7 is electrically connected to the power supply GND.

[0043] The collector of the NPN transistor T2 is electrically connected to the disable control input terminal of the functional drive output unit; the emitter of the transistor T2 is electrically connected to the power supply GND.

[0044] Its working principle mainly includes the following steps:

[0045] 1) Set N safety shutdown control circuits corresponding to N functional drive output units, where N≥1. When N=1, Figure 2 As shown, it is a single-channel safety shutdown control circuit used to control a single-channel functional drive output unit.

[0046] 2) If Figure 1 As shown, the state monitoring output of the system function control unit is connected to the state monitoring input of the system state monitoring unit. The enable / disable control output of the system function control unit is connected to the enable / disable control input of the function drive output unit via a safety shutdown control circuit. The shutdown control output of the system state monitoring unit is connected to the state feedback input of the system function control unit via a safety shutdown control circuit. The shutdown control output of the system state monitoring unit is connected to the enable / disable control input of the function drive output unit via a safety shutdown control circuit.

[0047] 3) When the system is operating normally, the enable / disable control output of the system function control unit is high, providing a high active input level to the function drive output unit through resistor R1, enabling the drive output. When the system function requires the drive output to be shut down normally, the enable / disable control output of the system function control unit is low, providing a low input level to the function drive output unit through resistor R1, shutting down the drive output. In this state, the system status monitoring unit monitors the status normally and outputs a high-level shutdown control signal. On the one hand, this signal is fed back to the system function control unit through R2, notifying the system function control unit. On the other hand, the system status monitoring unit has no effective shutdown control output for the function drive output unit. The base of transistor T1 is in the off state due to the pull-up resistors R3 and R5. Therefore, the base of transistor T2 has no start-up current and is in the off state. The shutdown control has no effect on the enable input of the function drive output unit.

[0048] 4) When the system operation state is abnormal and the enable / disable control output of the system function control unit is high, the system state monitoring unit detects the abnormal state and outputs a low-level shutdown control signal: on the one hand, the signal is fed back to the system function control unit through R2 to notify the system function control unit; on the other hand, the system state monitoring unit effectively shuts down the output of the function drive output unit. The base of the transistor T1 enters the on-state under the bias of the resistors R4 and R5, and the base of the transistor T2 enters the on-state through the VCC, T1 and R6 input turn-on current, forcing the enable input of the function drive output unit to be low, thereby shutting down the drive output.

[0049] It should be noted that when N≥2, Figure 3 The figure shows a multi-channel safety shutdown control circuit for controlling multiple functional drive output units. For the system status monitoring unit, only one shutdown control output terminal is required to meet the multi-channel drive output control requirements.

[0050] Example 2

[0051] like Figure 1 、 4 As shown in FIG5 , a safety shutdown control circuit is provided, including a resistor R1 , a resistor R2 , a resistor R3 , a resistor R6 , a resistor R7 and a transistor T2 .

[0052] One end of the resistor R1 is electrically connected to the enable / disable control output end of the system function control unit, and the other end of the resistor R1 is electrically connected to the enable / disable control input end of the function drive output unit.

[0053] One end of the resistor R2 is electrically connected to the shutdown control output end of the system state monitoring unit, and the other end of the resistor R2 is connected to the state feedback input end of the system function control unit.

[0054] The system status monitoring unit is electrically connected to the system function control unit, so that the system status monitoring unit can monitor the status of the system.

[0055] One end of the resistor R3 is electrically connected to the shutdown control output end of the system state monitoring unit, and the other end of the resistor R3 is connected to the power supply GND.

[0056] One end of the resistor R6 is electrically connected to the shutdown control output end of the system state monitoring unit, and the other end of the resistor R6 is electrically connected to the base of the NPN transistor T2.

[0057] One end of the resistor R7 is electrically connected to the base of the NPN transistor T2 , and the other end of the resistor R7 is electrically connected to the power supply GND.

[0058] The collector of the NPN transistor T2 is electrically connected to the disable control input terminal of the functional drive output unit; the emitter of the transistor T2 is electrically connected to the power supply GND.

[0059] A safety shutdown control method is provided, which mainly includes the following steps:

[0060] 1) Set N safety shutdown control circuits corresponding to N functional drive output units, where N≥1. When N=1, Figure 4 As shown, it is a single-channel safety shutdown control circuit used to control a single-channel functional drive output unit.

[0061] 2) If Figure 1 As shown, the state monitoring output of the system function control unit is connected to the state monitoring input of the system state monitoring unit. The enable / disable control output of the system function control unit is connected to the enable / disable control input of the function drive output unit via a safety shutdown control circuit. The shutdown control output of the system state monitoring unit is connected to the state feedback input of the system function control unit via a safety shutdown control circuit. The shutdown control output of the system state monitoring unit is connected to the enable / disable control input of the function drive output unit via a safety shutdown control circuit.

[0062] 3) When the system is operating normally, the enable / disable control output of the system function control unit is high, providing a high active input level to the function drive output unit through resistor R1, enabling the drive output. When the system function requires the drive output to be shut down normally, the enable / disable control output of the system function control unit is low, providing a low input level to the function drive output unit through resistor R1, shutting down the drive output. In this state, the system status monitoring unit monitors the state normally and outputs a low-level shutdown control signal: on the one hand, this signal is fed back to the system function control unit through R2, notifying the system function control unit; on the other hand, the system status monitoring unit has no effective shutdown control output for the function drive output unit, and the base of transistor T2 has no turn-on current, being in the shutdown state. The shutdown control has no effect on the enable input of the function drive output unit.

[0063] 4) When the system operation state is abnormal and the enable / disable control output of the system function control unit is high, the system state monitoring unit detects the abnormal state and outputs a high-level shutdown control signal: on the one hand, the signal is fed back to the system function control unit through R2 to notify the system function control unit; on the other hand, the system state monitoring unit effectively shuts down the output of the function drive output unit, and the base of the transistor T2 turns on the current through the received high level and the resistor R6 input, enters the on state, and forces the enable input of the function drive output unit to be low, thereby shutting down the drive output.

[0064] It should be noted that when N≥2, Figure 5 The figure shows a multi-channel safety shutdown control circuit for controlling multiple functional drive output units. For the system status monitoring unit, only one shutdown control output terminal is required to meet the multi-channel drive output control requirements.

[0065] It should be noted that the control algorithms or programs involved in the working principle of this embodiment are not within the scope of protection of the present invention and are only used to help those skilled in the art understand the technical solution of the present invention.

[0066] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any person skilled in the art can, without departing from the scope of the present invention, utilize the methods and technical content disclosed above to make many possible variations and modifications to the present invention, or modify it into equivalent embodiments with equivalent variations. Therefore, any equivalent variations based on the shape, structure, and principle of the present invention that do not depart from the content of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A safety shutdown control circuit, characterized in that: It includes resistor R1, resistor R2, resistor R6, resistor R7 and transistor T2; One end of the resistor R1 is connected to the output end of the system function control unit, and the other end of the resistor R1 is connected to the input end of the function drive output unit; One end of the resistor R2 is connected to the output end of the system status monitoring unit, and the other end of the resistor R2 is connected to the input end of the system function control unit; One end of the resistor R6 is directly or indirectly connected to the output end of the system status monitoring unit, and the other end of the resistor R6 is connected to the base of the transistor T2; One end of the resistor R7 is connected to the base of the transistor T2, and the other end of the resistor R7 is connected to the power supply GND; The collector of the transistor T2 is connected to the function drive output unit; the emitter of the transistor T2 is connected to the power supply GND.

2. A safety shutdown control circuit according to claim 1, characterized in that: When the resistor R6 is indirectly connected to the output terminal of the system state monitoring unit, a resistor R3, a resistor R4 and a transistor T1 are provided between the resistor R6 and the output terminal of the system state monitoring unit; One end of the resistor R3 is connected to the signal logic power supply VCC, and the other end of the resistor R3 is connected to the output end of the system status monitoring unit; One end of the resistor R4 is connected to the base of the transistor T1, and the other end of the resistor R4 is connected to the output end of the system status monitoring unit; The emitter of the transistor T1 is connected to the signal logic power supply VCC, and the collector of the transistor T1 is connected to one end of the resistor R6.

3. A safety shutdown control circuit according to claim 2, characterized in that: The system further includes a resistor R5 , one end of which is connected to the base of the transistor T1 , and the other end of which is connected to the signal logic power supply VCC.

4. The safety shutdown control circuit according to claim 1, wherein: When the resistor R6 is directly connected to the output end of the system state monitoring unit, the output end of the system state monitoring unit is connected to one end of the resistor R3 , and the other end of the resistor R3 is connected to the power supply GND.

5. The safety shutdown control circuit according to claim 1, characterized in that: The transistor T2 is configured as an NPN transistor.

6. A safety shutdown control circuit according to claim 2, characterized in that: The transistor T1 is configured as a PNP transistor.

Images