Beyond the Control Equations: An Artifact Study of Implementation Quality in Robot Control Software

A controller -- a software module managing hardware behavior -- is a key component of a typical robot system. While control theory gives safety guarantees for standard controller designs, the practical implementation of controllers in software introduces complexities that are often overlooked. Controllers are often designed in continuous space, while the software is executed in discrete space, undermining some of the theoretical guarantees. Despite extensive research on control theory and control modeling, little attention has been paid to the implementations of controllers and how their theoretical guarantees are ensured in real-world software systems. We investigate 184 real-world controller implementations in open-source robot software. We examine their application context, the implementation characteristics, and the testing methods employed to ensure correctness. We find that the implementations often handle discretization in an ad hoc manner, leading to potential issues with real-time reliability. Challenges such as timing inconsistencies, lack of proper error handling, and inadequate consideration of real-time constraints further complicate matters. Testing practices are superficial, no systematic verification of theoretical guarantees is used, leaving possible inconsistencies between expected and actual behavior. Our findings highlight the need for improved implementation guidelines and rigorous verification techniques to ensure the reliability and safety of robotic controllers in practice.

Before Autonomy Takes Control: Software Testing in Robotics

Robotic systems are complex and safety-critical software systems. As such, they need to be tested thoroughly. Unfortunately, robot software is intrinsically hard to test compared to traditional software, mainly since the software needs to closely interact with hardware, account for uncertainty in its operational environment, handle disturbances, and act highly autonomously. However, given the large space in which robots operate, anticipating possible failures when designing tests is challenging. This paper presents a mapping study by considering robotics testing papers and relating them to the software testing theory. We consider 247 robotics testing papers and map them to software testing, discussing the state-of-the-art software testing in robotics with an illustrated example, and discuss current challenges. Forming the basis to introduce both the robotics and software engineering communities to software testing challenges. Finally, we identify open questions and lessons learned.