Chapter Four · failure evidence

What Feedback & Closed-Loop Control got wrong, from 86 dissertations

These records demonstrate the operational trade-offs between open-loop execution and closed-loop feedback across robotics, chemical processes, and mechatronic systems. While open-loop methods frequently suffer from drift and disturbance accumulation, closed-loop feedback systems can fail due to latency, excessive gain tuning, sensor noise, or unmodeled plant interactions. These records come from PhD theses at 28 institutions, 2021 to 2026. Each links to its thesis. They were extracted by language models reading the full text, so treat each as a lead to read, not a verdict.

Open-loop control fails due to dynamic disturbances, drift, and lack of real-time state correction

27 theses · 12 institutions

Operating without closed-loop feedback leads to accumulated trajectory drift, unbounded covariance growth, and failure to track references under environmental uncertainty or contact variability. In multiple evaluations, open-loop policies were abandoned or lost to closed-loop controllers because they could not regulate against unmodeled dynamics and disturbances.

Tried and failed

open-loop optimal control during initialization phase applied to system startup trajectory tracking. Outcome: worse than baseline. Reason: lack of feedback during startup failed to outperform standard closed-loop trajectory tracking

Automated Optimization and Control of Modular Chemical Systems · MIT

Tried and failed

open-loop model predictive control using constraint-based models applied to bioreactor nutrient feed rate optimization. Reason: unmodeled environmental dynamics and residual metabolism caused nutrient accumulation and growth deviations without feedback

Genome-scale model-based approach to optimize nutrient supply for chlorella vulgaris · JScholarship

Tried and failed

open-loop transfer of simulation-optimized trajectories to hardware applied to locomotion controller for physical robots. Outcome: did not generalise. Reason: sim-to-real gap and unmodeled contact dynamics caused unpredictable execution without feedback

Robot Graph Grammars: Towards Custom Robots for Every Task · MIT

Tried and failed

open-loop actuation for manipulating flexible materials applied to automated loop lifting in robotic crocheting. Outcome: unstable. Reason: loose, deformable fabric introduced spatial variability, causing mechanical actuators to miss loops or lift inadequately

Croche-Matic – building a robot for crocheting 3D spherical form · Harvard

Lost to a baseline

The open-loop stochastic self-triggered MPC consumed significantly more resource and stayed farther from reference boundaries than the closed-loop feedback formulation.

Data-driven Methods for Control: from Linear to Lifting · EPFL

Lost to a baseline

Open-loop trajectory tracking of hydraulic actuator position resulted in substantially higher tracking error (16.65° RMSE for sinusoidal references) compared to closed-loop PI control (3.90° RMSE).

Sensing, Actuation, and Control of Soft Fluid-driven Robots by Liquid-elastomer Composite Sensors and Dielectric Elastomer Actuators · Harvard

Considered and rejected

Considered and rejected: Rejected open-loop / feed-forward GPS/INS integration configurations because reference and actual trajectories diverge, deteriorating linearity and process model assumptions over time; adopted feedback/closed-loop integration instead.

Vision based Real-Time Navigation with Unknown and Uncooperative Space Target · Carleton University Institutional Repository

Considered and rejected

Considered and rejected: Rejected open-loop charge execution at t=0 in favor of closed-loop MPC-style periodic recomputation to handle forecast disturbances, price changes, and parameter errors.

Smart Charging of Electric Vehicles: Algorithms, Ramifications, and Hardware Development · Georgia Tech

Considered and rejected

Considered and rejected: Rejected open-loop AOM RF frequency/amplitude control for lattice ramping due to drift and complexity, retaining closed-loop PID control

Elastic and inelastic dipolar scattering · MIT

Considered and rejected

Considered and rejected: Open-loop RF frequency/amplitude control of the AOM for deep lattice ramping due to drift and complexity, retaining closed-loop PID control

Elastic and inelastic dipolar scattering · MIT

Considered and rejected

Considered and rejected: Open-loop proportional distance control alone: rejected because steady-state following error grew with target speed, risking tag loss; replaced with PI distance control.

USE OF ARTIFICIAL FIDUCIAL MARKERS FOR USV SWARM COORDINATION · Calhoun

Considered and rejected

Considered and rejected: Rejected open-loop state covariance propagation for rendezvous chance constraints in favor of a feedback-augmented deadbeat impulsive controller to suppress unbounded covariance growth.

Fast and Resilient Optimization-based Control with Spacecraft Applications · ResearchWorks

Tried and failed

open-loop pulse programming of analog states applied to resistive switching memory devices. Outcome: unstable. Reason: stochastic switching prevented reproducible target resistance states and reliable retention without closed-loop verification

High-resolution peripheral circuits for multi-state memristors and their related applications · Imperial

Tried and failed

open-loop rate control transitions applied to vehicle trajectory planning. Outcome: unstable. Reason: lack of feedback during transitions accumulated trajectory drift and positional error

Adapting Random Tree Search to Fixed Wing Aerial Vehicles with Closed-Loop Prediction and Hybrid Control · Georgia Tech

Tried and failed

open-loop fixed timing switching control applied to resonant soft-switching power converters. Outcome: unstable. Reason: fixed delays failed during transients, causing hard-switching transitions and destructive overvoltage stresses

Multiport Power Electronics based on Four-Quadrant Soft-Switching Current-Source Converters · Georgia Tech

Tried and failed

open-loop robust control with uncertainty propagation applied to dynamic ambiguity set control. Outcome: unstable. Reason: Zero feedback gain fails to restrict the unbounded growth of dynamic uncertainty sets over time.

Data-driven distributionally robust model predictive control · Imperial

Lost to a baseline

Open-loop optimal contact control with 30-day delay resulted in 720 deaths per 100,000 (at 25% isolation) and 510 deaths (at 50% isolation), losing to feedback control which held deaths to 620 and 250 respectively.

Endogenous and Exogenous Control of Virus-Host Dynamics · Georgia Tech

Considered and rejected

Considered and rejected: Rejected open-loop control using optimal steady-state bus voltages because it lacks feedback accuracy and cannot regulate against disturbances.

Networked DC microgrids control system for optimal power exchange with guaranteed stability · Imperial

Considered and rejected

Considered and rejected: Rejected linear quadratic regulator (LQR) open-loop control because it lacks input constraints and infinite-time convergence assumptions are unrealistic

Early Prediction of Adverse Clinical Events and Optimal Intervention in Intensive Care Units · JScholarship

Considered and rejected

Considered and rejected: Rejected open-loop constant molar flux control for active equilibration due to first-order drift in total internal pressure caused by environmental oxygen perturbations.

Developing in situ instrumentation to monitor anthropogenic change · Woods Hole

Considered and rejected

Considered and rejected: Open-loop tetanic activation control: rejected because sustaining open-loop tetanus caused rapid muscle deterioration and tissue damage, requiring closed-loop proxy evaluation instead.

Rapid wingbeats in insects through supra-resonant elasticity and actuation · Georgia Tech

Lost to a baseline

Controller 1 (feedforward shape propagation) was completely outperformed by feedback Controllers 2 and 3 under unknown obstacles and poor initial contact, achieving 0% success compared to 100% success for feedback controllers.

Snake and Snake Robot Locomotion in Complex, 3-D Terrain · JScholarship

Considered and rejected

Considered and rejected: Rejected parameterising predicted control inputs as open-loop perturbation sequences {c_0|k, ., c_{N-1|k}} with fixed observer and feedback gains because it provides poor performance and small feasible sets under packet loss.

Robust and stochastic receding horizon control · Oxford

Tried and failed

single-step open-loop dynamic optimization applied to nonlinear bioreactor trajectory optimization. Outcome: did not converge. Reason: numerical solver failed over full horizon, requiring receding horizon optimization instead

Mathematical Formulation and Numerical Methods for the Optimization of Novel Biotherapeutics Manufacturing · MIT

Tried and failed

offline open-loop optimal control without state feedback applied to satellite rendezvous docking under dynamic perturbations. Outcome: did not converge. Reason: lack of feedback prevented correction for dynamic perturbations during execution

Distributed and Time-Varying Optimization for Autonomy and Decision-Making · Georgia Tech

Tried and failed

iterative unrolled deep learning prediction without feedback applied to structural topology optimization. Outcome: worse than baseline. Reason: Uncoupled density sequence prediction failed to maintain volume fraction constraints compared to coupled physical feedback models.

Deep learning frameworks for structural topology optimization · Iowa State

Tried and failed

open-loop model-based predictive scheduling without local sensors applied to precision agricultural irrigation management. Outcome: worse than baseline. Reason: overestimated growth model coefficients and comparison against an experienced baseline operator

Bringing the Water-Efficiency Benefits of Precision Irrigation to Resource-Constrained Farms Through an Automatic Scheduling-Manual Operation Irrigation Tool · MIT

Considered and rejected

Considered and rejected: Rejected open-loop / batch experimental design when intermediate experimental outcomes can actively inform subsequent design decisions in non-parallel settings.

Accounting for Computational Expenditures in Bayesian Experimental Design · MIT

Closed-loop feedback is outperformed by simpler open-loop or feedforward strategies

12 theses · 10 institutions

Complex closed-loop feedback loops frequently introduce computational overhead, actuator saturation near zero crossings, or excessive resource consumption compared to simpler open-loop baselines. In several implementations, open-loop current control, correlation methods, or baseline schedules achieved lower tracking error, reduced costs, and avoided hardware complexity.

Lost to a baseline

Sequential Open-Loop Control (OLC) achieved higher steady-state tracking accuracy than MPC across several prediction horizons (Figure 5.4).

Guidance and Navigation Algorithms for Spacecraft Low-Thrust Proximity Operations: Formation Flight in Circular Relative Orbit · IRIS - POLITO - prod

Lost to a baseline

For process LDH 6 final state estimation, the open-loop reference model was more accurate than the direct soft-sensor and PF observer.

Novel soft-sensor applications and mechanistic models for biomanufacturing with Escherichia coli · DSpace-CRIS at TU Wien

Lost to a baseline

Open-loop system with rho_s = 0.5 achieved lower mean peak age (Delta = 4) than pipelined closed-loop feedback systems when feedback was heavily bottlenecked (mu_f < 0.6).

Age- and deviation-of-information in networked cyber-physical systems · Leibniz Universität Hannover Repository

Considered and rejected

Considered and rejected: Rejected open-loop/closed-loop compensation mechanisms requiring active control rod feedback in favor of open-loop moving-average detrended oscillations.

Analysis and Reproduction of Stainless-steel Integral Experiments Towards Nuclear Data Assimilation · EPFL

Considered and rejected

Considered and rejected: Rejected using closed-loop torque control with dedicated output torque sensing, choosing open-loop current control of quasi-direct drive actuators to reduce mass and mechanical complexity.

Enhancing Human Locomotion using a Robotic Knee Exoskeleton · Georgia Tech

Considered and rejected

Considered and rejected: Rejected closed-loop feedback control for breakthrough concentration generation due to complexity of required electronics and programming, choosing open-loop control with manual calibration instead

Characterisation of porous materials for the adsorption of volatile organic compounds · Imperial

Considered and rejected

Considered and rejected: Closed-loop gradient algorithm rejected because open-loop correlation requires fewer samples, half the multiplications per sampling interval, and provides better noise accuracy.

NON-ADAPTIVE ECHO CANCELLATION · HARVEST

Lost to a baseline

On BDD Day-Urban sequences, PID closed-loop sensor control achieved 0.75-0.76 recall vs 0.80 for open-loop baseline.

Closed Loop Perception for Resource Efficient Autonomous Systems · Georgia Tech

Lost to a baseline

Feedforward-enhanced feedback control had lower experimental performance (3.7% THD) compared to dynamic cancellation control (2.9% THD) due to duty-ratio saturation near zero crossings creating a flat dead-band

CONTROL OF HIGH-POWER-DENSITY LINE-INTERFACED POWER CONVERTERS · Cornell

Tried and failed

high-frequency feedback loops in the datapath applied to network congestion control. Outcome: worse than baseline. Reason: excessive CPU overhead from frequent feedback computation degraded throughput

Toward Predictable Networks · Cornell

Lost to a baseline

In the modular CZ framework under varying traffic rates, the feedback controller incurred higher total cost in CZ1 (36.96 vs 34.23) and fixed-speed flow control incurred higher overall total objective (76.77 vs 74.72) than the baseline without flow control.

Safety-critical optimal control in autonomous traffic systems · OpenBU

Lost to a baseline

In decreasing inertia perturbations, the closed-loop controller achieved a cost of 3.19, performing worse than the open-loop model baseline cost of 2.87.

Neuro-musculoskeletal Models: A Tool to Study the Contribution of Muscle Dynamics to Biological Motor Control · Publikationssystem UB Tuebingen

Excessive feedback gains and aggressive tuning induce instability and actuator saturation

12 theses · 9 institutions

High feedback gains, aggressive adaptation rates, and derivative terms frequently destabilize plants by triggering persistent oscillations or driving actuators into saturation. In nonlinear and time-varying applications, excessive feedback caused closed-loop divergence, limit cycles, or unintended systemic breakdowns.

Tried and failed

nested force feedback in position control loop applied to series elastic actuator position control. Outcome: worse than baseline. Reason: Inner force feedback degraded stability margins, forcing smaller position gains and worsening position tracking accuracy.

Towards versatile, high-performing and interactive humanoids · UT Austin

Tried and failed

fully automated closed-loop environmental control applied to building HVAC systems. Outcome: unstable. Reason: complex feedback dynamics produced unintended systemic breakdowns rather than stable autonomous regulation

Remote Control: Art, Technology, and the Politics of Distance (1966-1972) · MIT

Tried and failed

Aggressive convergence rate optimization in feedback control applied to nonlinear dynamical systems. Outcome: unstable. Reason: Excessively high feedback gains induced actuator saturation in nonlinear simulation despite theoretical linear certification

Safe online learning for nonlinear dynamical systems using control contraction metrics · Cranfield

Tried and failed

adaptive feedforward control with high learning rates applied to robot motion control with sensory feedback. Outcome: unstable. Reason: Excessively high adaptation rate in the feedforward loop caused dynamic control instability across trials.

Bio-inspired robotics: efference copies and adaptive feedforward control · Imperial

Tried and failed

derivative action in PID feedback control applied to piezoelectric actuator stabilization. Outcome: unstable. Reason: derivative gain consistently induced closed-loop oscillations regardless of parameter tuning

Strong Light — Matter Interactions in a Bow-Tie Cavity and Machine Learning-Enhanced Cooling · MIT

Tried and failed

open-loop to closed-loop current ramp-down switching applied to sensorless motor drive control. Outcome: unstable. Reason: Excessive ramp-down slope drops current prematurely before phase error converges, causing torque and speed oscillations.

Sensorless control of motoring/generating system for future more-electric turboprop aircraft · University of Nottingham Repository

Tried and failed

constant gain PID feedback control applied to time-varying acoustic emission regulation. Outcome: unstable. Reason: spatial density variations and temporal clearance kinetics caused control loop divergence

Microbubble Dynamics Monitoring and Control for Diagnosis and Treatment of Brain Cancer · Georgia Tech

Tried and failed

hardware-inferred memory delay line with feedback applied to real-time digital audio processing. Outcome: unstable. Reason: synthesis failed to infer block RAM and uncontrolled compounding feedback caused signal instability

Audio Processing on Field-Programmable Gate Arrays · Harvard

Considered and rejected

Considered and rejected: Rejected using unrealistically high control gains in simulation to bridge the stride length gap between open-loop and closed-loop because they fail on physical hardware.

TOWARD HIGH-PERFORMANCE SIMPLE MODELS OF LEGGED LOCOMOTION · Penn

Tried and failed

Concave nonlinear feedback control policy applied to Decentralized agent distribution control. Outcome: unstable. Reason: Low feedback exponents caused persistent switching oscillations and high steady-state error near the target distribution.

Effective task allocation frameworks for large-scale multiple agent systems. · Cranfield

Tried and failed

droop control with instantaneous vector discretization applied to grid-connected inverter power regulation. Outcome: unstable. Reason: positive feedback occurs when phase angle difference enters 90 to 270 degrees, causing active power divergence

Vector Based Control for Power Electronics Dominated AC Power Grid · Virginia Tech

Tried and failed

linearized state-feedback control applied to bistable nonlinear reaction-diffusion PDEs. Outcome: unstable. Reason: linearization failed to capture nonlinear dynamics, allowing trajectories to escape toward an alternate stable steady state

Control of agent-based models across scales · Imperial

Hardware latency and communication delays destabilize feedback loops

11 theses · 9 institutions

Time delays from sensor conditioning, communication buses, and digital processing introduce severe phase lag that triggers oscillations and limits closed-loop bandwidth. In multiple systems, feedback signals arriving with millisecond-scale latency degraded disturbance rejection or destabilized physical hardware.

Tried and failed

two-loop acceleration feedback autopilot applied to aerodynamically unstable vehicle control. Outcome: unstable. Reason: extreme sensitivity to actuator dynamics and lag causes closed-loop instability without rate-damping inner loops

Smart Projectile Performance Augmentation Using an Articulating Nose · Georgia Tech

Tried and failed

maximizing closed-loop control bandwidth applied to time-delayed opto-mechatronic feedback systems. Outcome: worse than baseline. Reason: Latency and phase lag caused severe noise amplification and degraded low-frequency disturbance rejection.

Opto-mechatronic disturbance compensation for free-space optical satellite communication · DSpace-CRIS at TU Wien

Considered and rejected

Considered and rejected: Feeding back measured ergometer position directly into real-time closed-loop simulation: rejected because 1-2 ms hardware latency destabilized the loop, requiring feedback of prescribed position instead.

Rapid wingbeats in insects through supra-resonant elasticity and actuation · Georgia Tech

Considered and rejected

Considered and rejected: Rejected continuous on-balance feedback measurements because finite lock-in response time and feedback loop lag caused excessive measurement slowdown and errors compared to off-balance acquisition.

The Electronic Compressibility of Rhombohedral Graphene Multilayers · MIT

Tried and failed

continuous sinusoidal feedback actuation applied to real-time aeroelastic vibration damping. Outcome: too slow. Reason: Update rate lag degraded phase synchronization accuracy and control response speed.

It’s Not Just a Phase: Real-Time Aeroelastic Flutter Control Optical Flow Sensing and Piezoelectric Control of Aeroelastic Flutter · unevada

Considered and rejected

Considered and rejected: Rejected pure feedback control and teleoperation due to severe sensor/communication time delays and slow operational speed

Bio-Inspired Adaptive Control of Robotic Manipulators for Grasping in Orbital Space Missions · Carleton University Institutional Repository

Considered and rejected

Considered and rejected: Online maximum likelihood estimation (MLE) in real-time feedback loop rejected in favor of reactive extremum seeking control due to computational latency in the temporal control budget.

Evaluating and optimizing the performance of real-time feedback-driven single particle tracking microscopes through the lens of information and optimal control · OpenBU

Tried and failed

coordinated feedback control with parameter tracking applied to distributed energy frequency regulation. Outcome: unstable. Reason: communication delays around 200 ms induce sustained oscillations through resonant mode amplification

Frequency Control of Virtual Power Plants · Research Repository UCD

Tried and failed

analog LVDT conditioning IC for position sensing applied to magnetic levitation closed-loop control. Outcome: unstable. Reason: signal processing IC introduced excessive phase lag around 100 Hz into the feedback loop

Bearingless Slice Motor and 6-DoF Position Sensor for Extracorporeal Pump · MIT

Lost to a baseline

Baseline strategy moving towards the intruder's azimuth angle achieved larger terminal separation ls than the optimal strategy in certain high-order dynamic trials due to cross-feedback computation delay.

Perception-Action Loop for Multi-Robot Systems with Deep Learning · Penn

Tried and failed

GPIB-controlled power supply for digital feedback loop applied to interferometer fringe locking. Outcome: unstable. Reason: Communication latency and quantized output steps caused discrete voltage jumps and signal disruptions.

Measurement of phonon angular momentum via the Einstein-de Haas effect, fiber-optic interferometry, and a high-Q oscillator · UT Austin

Sensor noise and signal differentiation corrupt feedback and state estimation

6 theses · 5 institutions

Directly feeding back noisy measurements or numerically differentiating latency-affected signals introduces high-frequency actuator chatter and estimator degradation. Closed-loop parameter identification also becomes biased and inconsistent when measurement noise correlates with control inputs under misspecified noise models.

Lost to a baseline

In the introductory benchmark with measurement noise disturbance n(t) at t = 7 s, H-infinity reached a peak amplitude of 1.341 and recovered in 98.86 ms, whereas Polynomial control took 996.5 ms (reaching amplitude 1.338) and State Feedback took 999 ms (reaching amplitude 1.802).

Analisi e paragone di diversi concetti di controllo per un pendolo inverso con un modo di risonanza · SUPSI - ARIS

Tried and failed

direct force sensor feedback control applied to haptic robot manipulator interaction. Outcome: unstable. Reason: sensor noise in the closed-loop force feedback severely degraded control stability

Virtual mechanism with feedback force · Iowa State

Considered and rejected

Considered and rejected: Rejected numerical differentiation of slow-sampled, latency-affected exteroceptive pose signals for floating-base velocity feedback due to high-frequency actuator chatter and instability.

Employing symmetry in dynamics and motion control of robotic mechanisms · DSpace-CRIS at TU Wien

Considered and rejected

Considered and rejected: Rejected full-state feedback control for physical implementations due to degradation/instability from measurement noise, delay, derivative noise, and signal saturation.

Design Methodologies for Simple Adaptive Controllers with Applications to Spacecraft Proximity Operations · Carleton University Institutional Repository

Tried and failed

Direct identification under feedback applied to closed-loop dynamic systems. Reason: Noise-input correlation under misspecified noise models produces biased, inconsistent parameter estimates

Learning and Control with Generalization and Stability Certificates · EPFL

Considered and rejected

Considered and rejected: Rejected direct numerical differentiation of the cantilever deflection signal for ORT velocity feedback due to amplified noise and estimator computational latency, choosing a fixed time-delay instead.

Data-Driven Methods for Controller Design in Atomic Force Microscopy · EPFL

Open-loop parameter tuning and training fail during closed-loop execution

5 theses · 4 institutions

Optimizing models or control trajectories solely on open-loop data fails to account for downstream plant dynamics and recurrent feedback interactions. When deployed in closed-loop settings, these open-loop calibrated controllers accumulate integration errors and induce severe oscillatory behavior.

Tried and failed

piecewise-affine autoregressive modeling in predictive control applied to building HVAC frequency response control. Outcome: did not generalise. Reason: superior open-loop prediction accuracy did not translate to improved closed-loop tracking performance

Applications of Data-driven Predictive Control to Building Energy Systems · EPFL

Tried and failed

tuning MPC using open-loop trajectories applied to legged robot closed-loop control. Outcome: did not generalise. Reason: approximate discrete-time dynamics compounded integration errors like foot penetration and slip during closed-loop execution

Tailoring Complexity of Model-Based Controllers for Legged Robots · MIT

Tried and failed

open-loop parameter calibration excluding downstream plant dynamics applied to actuator control driven by biosignals. Outcome: unstable. Reason: omitting plant dynamics and feedback controller during optimization caused severe oscillatory behavior during closed-loop execution

Toward impedance control in human-machine interfaces for upper-limb prostheses · Imperial

Considered and rejected

Considered and rejected: Rejected pure open-loop training dataset evaluation for LSTM building dynamics in favor of closed-loop multi-step autoregressive rollout evaluation to test error accumulation and stability

Deep Reinforcement Learning-based Control Strategies for Enhancing Energy Management in HVAC Systems · IRIS - POLITO - prod

Tried and failed

static input balance tuned in isolated units applied to recurrently connected network simulations. Outcome: unstable. Reason: isolated tuning failed to account for recurrent network feedback dynamics

Simulation of the mouse visual cortex · EPFL

Pure feedback control fails without feedforward or predictive augmentation

4 theses · 3 institutions

Relying strictly on reactive feedback without feedforward terms or integral action leaves persistent steady-state tracking errors and poor dynamic compensation. Non-predictive feedback controllers exhibited inferior reference tracking compared to two-degree-of-freedom and predictive architectures.

Lost to a baseline

Omitting linear feedback gain adaptation (ˆkx adaptation turned off, γx = 0) resulted in increased oscillations and worse tracking error performance compared to adapting linear feedback gains.

Robust and Model Reference Adaptive Control for Nonlinear Uncertainty in Native Space · Virginia Tech

Considered and rejected

Considered and rejected: Rejected pure feedback PID low-level SEA control because human tissue damping and dynamic back-driving degraded tracking without feedforward compensation.

Adaptive User State Estimation for Assisting Human Locomotion Using Powered Hip Exoskeletons · Georgia Tech

Lost to a baseline

PD trajectory tracking under feedback-only control exhibited an average steady-state tracking error of e_avg = 0.0193 m due to lack of feed-forward or integral terms.

Multi-Objective Control for Physical and Cognitive Human-Exoskeleton Interaction · Virginia Tech

Lost to a baseline

Non-predictive controllers (PI and state feedback) achieved lower determination coefficients (R2 = 0.613 and R2 = 0.857) than the proposed 2DoF controller (R2 = 0.947) and MPC (R2 = 0.987) for NOx output tracking without input saturation.

A multi-level cooperative strategy for reducing fuel consumption and transient pollutant emissions of hybrid electric vehicles · DSpace-CRIS at TU Wien

Left open by the authors

Problems the authors named and did not get to.

Left open

Integrate online analytical sensors with continuous-flow reactors to enable real-time closed-loop feedback control of nanomaterial synthesis parameters. Blocker: Requires a physical continuous-flow reactor setup and integrated online analytical hardware.

Scalable Synthesis of Nanomaterials in Continuous-Flow Reactors · Georgia Tech

Left open

Develop a closed-loop feedback system controlling heating and cooling rates or thermal training for repeatable SMA actuation strain in knitted textiles. Blocker: Requires the physical knitted textile apparatus, Nitinol SMA actuators, sensors, and thermal control hardware

Leveraging Fabric Substructure Variations of Actuator-Integrated Robotic Textiles for Wearable Applications · Cornell

Left open

Implement closed-loop feedback or robust model predictive control under uncertainty for the simulated cellulose oxidation reactor. Blocker: None

Set-Based Fault Diagnosis and Dynamic Optimization of a Cellulose Oxidation Reactor · Georgia Tech

Left open

Perform closed-loop conditional auditory feedback with a 10 ms window across multiple discrete feedback delays to validate the synaptic eligibility trace shape. Blocker: Requires live zebra finches, chronic Neuropixels 2.0 neural implants, and specialized closed-loop electrophysiology wet-lab hardware.

Driving Temporally Precise Learning in Individual Premotor Neurons using Closed-Loop Neurofeedback · MIT

Left open

Apply the Limited Individual Lifetime Differential Evolution algorithm to optimize experimental Bose-Einstein condensate cycle parameters and cycle time. Blocker: Requires direct feedback and closed-loop control on the physical cold-atom experimental apparatus.

Experimental setup for fast BEC generation and number-stabilized atomic ensembles · Leibniz Universität Hannover Repository

Left open

Integrate high-level planning with a reusable atomic skill library to handle noisy execution feedback and compounding real-world errors in robotic manipulation. Blocker: Requires a physical robot manipulation setup and environment to evaluate closed-loop real-world error recovery.

Leveraging Pretrained Vision and Language Models for Robotic Manipulation · Georgia Tech

Left open

Test timing-specified robotic handover controllers with corrective feedback mechanisms in real-world industrial environments with human workers. Blocker: Requires physical industrial robotic manipulators and access to real industrial operating environments.

Robot Controllers, Gaze Behaviors and Human Motion Datasets for Object Handovers · Cornell

Left open

Simulate bimanual haptic feedback within motor control models to optimize feedback gains and modalities. Blocker: Specific motor control model formulations and objective functions for optimization are not detailed

Bimanual coordination classification, influence, and haptic augmentation for human-operated robotic systems · UT Austin

Left open

Develop and implement adaptive Smith-predictor-based feedback controllers for improved setpoint regulation in rolling-diaphragm hydrostatic transmission actuators. Blocker: Requires the physical hydrostatic transmission robotic hardware or proprietary experimental setup for validation

Rolling-diaphragm hydrostatic transmission for the remote actuation of high-performance robots · IRIS - UNITN - prod

Left open

Extend the causal discovery architecture to model cyclic feedback relationships and time-resolved dynamic systems via steady-states or stochastic differential equations. Blocker: None

Practical Algorithms for Modeling Causality to Accelerate Scientific Discovery · MIT

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