safety margin
A Details of Platform 473 A.1 Flight Dynamics Model
The frame's origin is fixed at The motion equations are derived from Newton's second law for an air vehicle, resulting in six core The inputs for the FPEs are the aircraft's attitude quaternion components along with the components The system comprising (CLMEs)-(CAMEs)-(FPEs)-(KEs), i.e., 1, 12, 15, and 16, represents The task scenarios can be categorized by objectives into Heading, Control, and Tracking . This work designs a hierarchical control algorithm for this task. RL Methods We use PPO for Heading and Control tasks in fixed-wing aircraft. The structure for hierarchical RL method is shown in Figure 10. The PPO algorithm's parameter settings are as follows: the learning rate is set to "128 128", and the recurrent hidden layer size is 128 with a single recurrent layer.
Smooth path planning with safety margins using Piece-Wise Bezier curves
Andrei, Iancu, Kloetzer, Marius, Mahulea, Cristian, Dosoftei, Catalin
In this paper, we propose a computationally efficient quadratic programming (QP) approach for generating smooth, $C^1$ continuous paths for mobile robots using piece-wise quadratic Bezier (PWB) curves. Our method explicitly incorporates safety margins within a structured optimization framework, balancing trajectory smoothness and robustness with manageable numerical complexity suitable for real-time and embedded applications. Comparative simulations demonstrate clear advantages over traditional piece-wise linear (PWL) path planning methods, showing reduced trajectory deviations, enhanced robustness, and improved overall path quality. These benefits are validated through simulations using a Pure-Pursuit controller in representative scenarios, highlighting the practical effectiveness and scalability of our approach for safe navigation.
A Physics-Informed Neural Network Approach for UAV Path Planning in Dynamic Environments
Unmanned aerial vehicles (UAVs) operating in dynamic wind fields must generate safe and energy-efficient trajectories under physical and environmental constraints. Traditional planners, such as A* and kinodynamic RRT*, often yield suboptimal or non-smooth paths due to discretization and sampling limitations. This paper presents a physics-informed neural network (PINN) framework that embeds UAV dynamics, wind disturbances, and obstacle avoidance directly into the learning process. Without requiring supervised data, the PINN learns dynamically feasible and collision-free trajectories by minimizing physical residuals and risk-aware objectives. Comparative simulations show that the proposed method outperforms A* and Kino-RRT* in control energy, smoothness, and safety margin, while maintaining similar flight efficiency. The results highlight the potential of physics-informed learning to unify model-based and data-driven planning, providing a scalable and physically consistent framework for UAV trajectory optimization.
Safe Autonomous Environmental Contact for Soft Robots using Control Barrier Functions
Dickson, Akua K., Garcia, Juan C. Pacheco, Anderson, Meredith L., Jing, Ran, Alizadeh-Shabdiz, Sarah, Wang, Audrey X., DeLorey, Charles, Patterson, Zach J., Sabelhaus, Andrew P.
Robots built from soft materials will inherently apply lower environmental forces than their rigid counterparts, and therefore may be more suitable in sensitive settings with unintended contact. However, these robots' applied forces result from both their design and their control system in closed-loop, and therefore, ensuring bounds on these forces requires controller synthesis for safety as well. This article introduces the first feedback controller for a soft manipulator that formally meets a safety specification with respect to environmental contact. In our proof-of-concept setting, the robot's environment has known geometry and is deformable with a known elastic modulus. Our approach maps a bound on applied forces to a safe set of positions of the robot's tip via predicted deformations of the environment. Then, a quadratic program with Control Barrier Functions in its constraints is used to supervise a nominal feedback signal, verifiably maintaining the robot's tip within this safe set. Hardware experiments on a multi-segment soft pneumatic robot demonstrate that the proposed framework successfully maintains a positive safety margin. This framework represents a fundamental shift in perspective on control and safety for soft robots, implementing a formally verifiable logic specification on their pose and contact forces.
Enhanced Mean Field Game for Interactive Decision-Making with Varied Stylish Multi-Vehicles
Zheng, Liancheng, Tian, Zhen, He, Yangfan, Liu, Shuo, Chen, Huilin, Yuan, Fujiang, Peng, Yanhong
This paper presents an MFG-based decision-making framework for autonomous driving in heterogeneous traffic. To capture diverse human behaviors, we propose a quantitative driving style representation that maps abstract traits to parameters such as speed, safety factors, and reaction time. These parameters are embedded into the MFG through a spatial influence field model. To ensure safe operation in dense traffic, we introduce a safety-critical lane-changing algorithm that leverages dynamic safety margins, time-to-collision analysis, and multi-layered constraints. Real-world NGSIM data is employed for style calibration and empirical validation. Experimental results demonstrate zero collisions across six style combinations, two 15-vehicle scenarios, and NGSIM-based trials, consistently outperforming conventional game-theoretic baselines. Overall, our approach provides a scalable, interpretable, and behavior-aware planning framework for real-world autonomous driving applications.
Toward a Holistic Multi-Criteria Trajectory Evaluation Framework for Autonomous Driving in Mixed Traffic Environment
Naidja, Nouhed, Font, Stรฉphane, Revilloud, Marc, Sandou, Guillaume
--This paper presents a unified framework for the evaluation and optimization of autonomous vehicle trajectories, integrating formal safety, comfort, and efficiency criteria. An innovative geometric indicator, based on the analysis of safety zones using adaptive ellipses, is used to accurately quantify collision risks. Our method applies the Shoelace formula to compute the intersection area in the case of misaligned and time-varying configurations. Comfort is modeled using indicators centered on longitudinal and lateral jerk, while efficiency is assessed by overall travel time. These criteria are aggregated into a comprehensive objective function solved using a PSO-based algorithm. The approach was successfully validated under real traffic conditions via experiments conducted in an urban intersection involving an autonomous vehicle interacting with a human-operated vehicle, and in simulation using data recorded from human driving in real traffic. Current research on autonomous vehicles and intelligent transport systems underlines the necessity for advanced decision-making frameworks that effectively manage multiple objectives. Among these objectives, safety retains the highest priority, requiring the vehicles to not only avoid collisions, but also to comply with traffic rules as well as exhibit a predictable behavior in complex urban environments. While safety is paramount, it is also essential to maintain the system's efficiency by optimizing traffic flows, minimizing delays, and reducing congestion, especially as transport infrastructures become increasingly interconnected. In light of the above, it is clear that balancing safety, efficiency, and comfort is not just a conceptual ideal but rather a requirement that shapes autonomous vehicle decision-making frameworks.
WinkTPG: An Execution Framework for Multi-Agent Path Finding Using Temporal Reasoning
Yan, Jingtian, Smith, Stephen F., Li, Jiaoyang
Planning collision-free paths for a large group of agents is a challenging problem with numerous real-world applications. While recent advances in Multi-Agent Path Finding (MAPF) have shown promising progress, standard MAPF algorithms rely on simplified kinodynamic models, preventing agents from directly following the generated MAPF plan. To bridge this gap, we propose kinodynamic Temporal Plan Graph Planning (kTPG), a multi-agent speed optimization algorithm that efficiently refines a MAPF plan into a kin-odynamically feasible plan while accounting for uncertainties and preserving collision-freeness. Building on kTPG, we propose Windowed kTPG (WinkTPG), a MAPF execution framework that incrementally refines MAPF plans using a window-based mechanism, dynamically incorporating agent information during execution to reduce uncertainty. Experiments show that WinkTPG can generate speed profiles for up to 1,000 agents in 1 second and improves solution quality by up to 51.7% over existing MAPF execution methods.
Captivity-Escape Games as a Means for Safety in Online Motion Generation
Bohn, Christopher, Hess, Manuel, Hohmann, Sรถren
This paper presents a method that addresses the conservatism, computational effort, and limited numerical accuracy of existing frameworks and methods that ensure safety in online model-based motion generation, commonly referred to as fast and safe tracking. Computational limitations restrict online motion planning to low-fidelity models. However, planning with low-fidelity models compromises safety, as the dynamic feasibility of resulting reference trajectories is not ensured. This potentially leads to unavoidable tracking errors that may cause safety-critical constraint violations. Existing frameworks mitigate this safety risk by augmenting safety-critical constraints in motion planning by a safety margin that prevents constraint violations under worst-case tracking errors. However, the methods employed in these frameworks determine the safety margin based on a heuristically selected performance of the planning model, which likely results in overly conservative reference trajectories. Furthermore, these methods are computationally intensive, and the state-of-the-art method is limited in numerical accuracy. We adopt a different perspective and address these limitations with a method that mitigates conservatism in existing frameworks by adapting the planning model performance to a given safety margin. Our method achieves numerical accuracy and requires significantly less computation time than existing methods by leveraging a captivity-escape game, which is a specific zero-sum differential game formulated in this paper. We demonstrate our method using a numerical example and compare it to the state of the art.
Robustified Time-optimal Point-to-point Motion Planning and Control under Uncertainty
This paper proposes a novel approach to formulate time-optimal point-to-point motion planning and control under uncertainty. The approach defines a robustified two-stage Optimal Control Problem (OCP), in which stage 1, with a fixed time grid, is seamlessly stitched with stage 2, which features a variable time grid. Stage 1 optimizes not only the nominal trajectory, but also feedback gains and corresponding state covariances, which robustify constraints in both stages. The outcome is a minimized uncertainty in stage 1 and a minimized total motion time for stage 2, both contributing to the time optimality and safety of the total motion. A timely replanning strategy is employed to handle changes in constraints and maintain feasibility, while a tailored iterative algorithm is proposed for efficient, real-time OCP execution.