Provably-Safe Stein Variational Clarity-Aware Informative Planning

Submitted to Learning for Dynamics & Control Conference 2026


1University of Michigan Ann Arbor
2Embry-Riddle Aeronautical University
* Equal Contribution

A clarity-aware informative planner that maintains a distribution over trajectories via Stein variational inference, models spatiotemporal information decay, and guarantees real-time safety using gatekeeper safety filter.

Abstract

Autonomous robots are increasingly deployed for information-gathering tasks in environments that vary across space and time. Planning informative and safe trajectories in such settings is challeng- ing because information decays when regions are not revisited. Most existing planners model infor- mation as static or uniformly decaying, ignoring environments where the decay rate varies spatially; those that model non-uniform decay often overlook how it evolves along the robot’s motion, and almost all treat safety as a soft penalty. In this paper, we address these challenges. We model uncer- tainty in the environment using clarity, a normalized representation of differential entropy from our earlier work that captures how information improves through new measurements and decays over time when regions are not revisited. Building on this, we present Stein Variational Clarity-Aware Informative Planning, a framework that embeds clarity dynamics within trajectory optimization and enforces safety through a low-level filtering mechanism based on our earlier gatekeeper frame- work for safety verification. The planner performs Bayesian inference-based learning via Stein variational inference, refining a distribution over informative trajectories while filtering each nom- inal Stein informative trajectory to ensure safety. Simulations across environments with varying decay rates and obstacles demonstrate consistent safety and reduced information deficits.

Framework Overview

Framework Overview

We quantify uncertainty using clarity, which evolves over time as the robot gathers measurements and decays when regions are not revisited. Instead of precomputing a static target distribution, we directly couple the robot's motion with the clarity dynamics, enabling the planner to reason about spatiotemporal information evolution. To generate informative motion, we maintain a distribution of candidate trajectories using Stein variational inference, allowing the planner to explore multiple informative strategies in parallel. For safety, each trajectory is evaluated using a gatekeeper safety filter, which certifies whether its execution remains within the safe set and has a valid backup. The robot executes only the informative and safety-verified trajectory, ensuring reliable and adaptive exploration in spatiotemporally evolving environments.

Experiments

We demonstrate the framework in action on a real quadrotor platform operating in an environment with obstacles. The experiments showcase the planner's ability to generate informative trajectories that adapt to spatiotemporal information evolution while maintaining safety guarantees through the gatekeeper filter.

Simulation Results

Simulation results demonstrating the performance across various environments with different decay rates and obstacle configurations.

Environment 1

Simulation 1
Target Clarity Map 1

Target Clarity Field

Decay Field 1

Decay Field

Environment 2

Simulation 2
Target Clarity Map 2

Target Clarity Field

Decay Field 2

Decay Field

Environment 3

Simulation 3
Target Clarity Map 3

Target Clarity Field

Decay Field 3

Decay Field

Environment 4

Simulation 4
Target Clarity Map 4

Target Clarity Field

Decay Field 4

Decay Field

Environment 5

Simulation 5
Target Clarity Map 5

Target Clarity Field

Decay Field 5

Decay Field

Environment 6

Simulation 6
Target Clarity Map 6

Target Clarity Field

Decay Field 6

Decay Field

Environment 7

Simulation 7
Target Clarity Map 7

Target Clarity Field

Decay Field 7

Decay Field

Environment 8

Simulation 8
Target Clarity Map 8

Target Clarity Field

Decay Field 8

Decay Field

Environment 9

Simulation 9
Target Clarity Map 9

Target Clarity Field

Decay Field 9

Decay Field

Environment 10

Simulation 10
Target Clarity Map 10

Target Clarity Field

Decay Field 10

Decay Field

Environment 11

Simulation 11
Target Clarity Map 11

Target Clarity Field

Decay Field 11

Decay Field

Environment 12

Simulation 12
Target Clarity Map 12

Target Clarity Field

Decay Field 12

Decay Field

Environment 13

Simulation 13
Target Clarity Map 13

Target Clarity Field

Decay Field 13

Decay Field

Environment 14

Simulation 14
Target Clarity Map 14

Target Clarity Field

Decay Field 14

Decay Field

Environment 15

Simulation 15
Target Clarity Map 15

Target Clarity Field

Decay Field 15

Decay Field

Environment 16

Simulation 16
Target Clarity Map 16

Target Clarity Field

Decay Field 16

Decay Field

Environment 17

Simulation 17
Target Clarity Map 17

Target Clarity Field

Decay Field 17

Decay Field

Environment 18

Simulation 18
Target Clarity Map 18

Target Clarity Field

Decay Field 18

Decay Field

Environment 19

Simulation 19
Target Clarity Map 19

Target Clarity Field

Decay Field 19

Decay Field

Environment 20

Simulation 20
Target Clarity Map 20

Target Clarity Field

Decay Field 20

Decay Field