Model Based Synthesis of Control Software from System Level Formal Specifications

TL;DR

This paper introduces a formal model-based method and a tool for automatically synthesizing control software for embedded systems from system-level specifications, ensuring correctness and real-time performance.

Contribution

It presents a novel algorithm and tool that generate correct control software from formal models and specifications, with proven feasibility on real-world examples.

Findings

Synthesizes control software with linear WCET in AD bits

Successfully applied to buck DC-DC converter and inverted pendulum

Ensures safety and liveness specifications are met

Abstract

Many Embedded Systems are indeed Software Based Control Systems, that is control systems whose controller consists of control software running on a microcontroller device. This motivates investigation on Formal Model Based Design approaches for automatic synthesis of embedded systems control software. We present an algorithm, along with a tool QKS implementing it, that from a formal model (as a Discrete Time Linear Hybrid System) of the controlled system (plant), implementation specifications (that is, number of bits in the Analog-to-Digital, AD, conversion) and System Level Formal Specifications (that is, safety and liveness requirements for the closed loop system) returns correct-by-construction control software that has a Worst Case Execution Time (WCET) linear in the number of AD bits and meets the given specifications. We show feasibility of our approach by presenting experimental results on using it to synthesize control software for a buck DC-DC converter, a widely used mixed-mode analog circuit, and for the inverted pendulum.