A functional safety circuit for automotive controller

Abstract

The invention discloses a functional safety circuit and control method for an automobile controller. The method is characterized in that an input voltage, an output voltage and a watchdog feed signalare monitored in real time; when the input voltage, the output voltage and the watchdog feed signal are normal, an MCU module controls an output drive control module to drive the load to work; and when the input voltage, or the output voltage, or the watchdog feed signal is normal, a limp detection control module controls the output drive control module to drive the load to work. When a system power supply and a single-chip microcontroller are normal, the functional safety circuit adopts a normal working mode to drive the load to work; when a main power supply or the single-chip microcomputerof a vehicle control system has fault, a backup power supply, a back-up circuit and a limp circuit are started, and a limp working mode is adopted to drive the load to work, thereby ensuring normal work of an automobile and ensuring safety of the vehicle and people; and the functional safety circuit can meet ISO26262 functional safety requirements, and has the advantages of high universality, highreliability, low static power consumption and low cost.

Description

technical field [0001] The invention belongs to the technical field of automobile control function safety, and in particular relates to a function safety circuit used for an automobile controller. Background technique [0002] With the increasing complexity of automotive electronic control systems, the risks from system failure and random hardware failure are also increasing, and the safety performance of automotive electronic products has become very important. The International Organization for Standardization officially promulgated the automotive functional safety standard ISO26262 in November 2011. Automotive functional safety is to avoid unacceptable risks caused by system functional failures. It determines the division of a system or a certain component of the system according to the degree of safety risk. There are corresponding definitions and requirements for each level of security requirements up to D, among which D level has the most stringent requirements. In or...

AI Technical Summary

Problems solved by technology

In order to meet the level requirements, you can choose the corresponding level of devices, but the price is high, and it is not necessarily available. Redundancy measures and fault self-recovery measures can also be used to reduce the level requirements of the devices. This method is more common in the industry.

There are many ways to adopt redundancy measures (that is, to design multiple sets of the same equipment as backup) and fault self-recovery measures, but they have common disadvantages: poor versatility, low performance, large static power consumption, high cost, and inconvenient writing programs, etc.

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