Dual Microcontroller Battery Management System for Functional Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current battery management systems face challenges in synchronizing data from high-voltage and low-voltage sides, requiring complex computation and high software involvement to ensure functional safety, particularly in achieving high ASIL levels for lithium ion battery systems used in vehicles and consumer devices.
Innovation Solution
A battery management system with dual independent communication lines and microcontrollers allows for simultaneous data capture and evaluation of battery modules, reducing software involvement and enhancing hardware redundancy, enabling simpler synchronization and increased functional safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a central controller with redundant microcontrollers is used to monitor battery cells, then functional safety and reliability are improved, but data synchronization complexity and software involvement increase
Solution Approach 1:
The battery management system is segmented into multiple independent monitoring paths: a first monitoring path with a first microcontroller and first measuring units, and a second monitoring path with a second microcontroller and second measuring units. Each path independently monitors battery parameters and can independently determine battery status, eliminating the need for complex data synchronization between redundant microcontrollers while maintaining high functional safety through diversified monitoring approaches.
2Reliability
If redundant measurement and evaluation paths are implemented, then functional safety is improved, but hardware complexity increases
Solution Approach 1:
The system divides monitoring functions into separate segments: voltage measurement by first measuring units, current measurement by second measuring units, with each having its dedicated microcontroller and evaluation path. This segmentation allows independent operation of each monitoring path, reducing hardware interdependencies and simplifying the overall system architecture while maintaining redundancy for safety.
Solution Approach 2:
Both the first and second monitoring paths are designed with universal evaluation capabilities that can independently assess battery status using their respective measurements. The first microcontroller evaluates voltage data from first measuring units, while the second microcontroller evaluates current data from second measuring units, with both paths converging on the same safety determination logic, reducing the need for additional specialized hardware.
3Reliability
If independent evaluation by multiple microcontrollers is implemented, then reliability is improved, but programming complexity and software involvement increase
Solution Approach 1:
The software architecture is segmented into independent evaluation modules: a first evaluation module in the first microcontroller that processes voltage measurements, and a second evaluation module in the second microcontroller that processes current measurements. Each module operates independently with its own measurement data, eliminating the need for complex inter-microcontroller software synchronization while maintaining comprehensive battery monitoring through diversified evaluation paths.
Data Source
AI summary
A battery management system includes several first measuring units, each associated with at least one respective battery module of the battery to detect a measured variable. The battery management system also includes a control device having a first microcontroller and a second microcontroller, a first communication connection configured to transfer data between the first measuring units and the control device, and several second measuring units configured to detect the measured variable from the battery modules of the battery in addition to the detection of the measured variable by the first measuring units. A second communication connection is used to transfer data between the second measuring units and the control device. The first microcontroller is configured to evaluate measurement data detected by the first measuring units, and the second microcontroller is configured to evaluate measurement data detected by the second measuring units independently of the first microcontroller.