This paper presents a performance comparison of different estimation and prediction techniques applied to the problem of tracking multiple robots. The main performance criteria are the magnitude of the estimation or prediction error, the computational effort and the robustness of each method to non-Gaussian noise. Among the different techniques compared are the well known Kalman filters and their different variants (e.g. extended and unscented), and the more recent techniques relying on Sequential Monte Carlo Sampling methods, such as particle filters and Gaussian Mixture Sigma Point Particle Filter.
Table 1: Summary of Bayesian prediction techniques compared in the present work.
Initial state estimate:
x^0=E[x0]
Initial state covariance:
P0=E[(x0−x^0)(x0−x^0)T]
Process noise covariance:
Q0=E[(v0−vˉ0)(v0−vˉ0)T]
Measurement noise covariace:
R0=E[(w0−wˉ0)(w0−w^0)T]
Algorithm 1 Extended Kalman Filter (EKF)
Symbol
Description
Robot Parameters
o1 , o2 , o3
rear, front-right and front-left wheels
m
robot’s mass
I0
robot’s inertia moment
r
wheel radius
L
body radius
Table 2: Notation for the model equations of the three-wheel robot.
Figure 1: Robot coordinate frame {xr,xr} fixed to the robot’s body (local coordiantes) and the traction forces f1 , f2 and f3 of the wheels.
Figure 2: World coordinate frame {xw,yw} fixed to the court (global coordinates) and two teams of RoboCup F-180 robots.
Figure 3: Forces acting on the robot and velocity components (see Table 2 for notation details).
Figure 4: PUC’s RoboCup F-180 system architecture.
Figure 5: Six different reference trajectories employed in the simulations.
Figure 6: Examples of the measured noisy trajectory corresponding to trajectory in the first row, second column of fig. 5 for different noise realizations.
RMSE w/IF
RMSE wo/IF
Tc/Tcmin
Tc/Tcmin
Filter
Position [ m ]
Heading [ rad ]
Position [ m ]
Heading [ rad ]
w/IF
wo/IF
EKF
0.0048 b
0.2326
0.0229 b
0.2674
1.000
1.000
DD1
0.0434
0.1386
0.0491 c
0.1951
3.566
3.729
DD2
0.0342
0.1363
0.0491
0.1947
3.566
3.729
UKF
0.0379
0.0398 c
0.1101
0.1399 c
3.758
3.971
CDKF
0.0105 c
0.0518
0.1100
0.1398 b
3.727
3.960
Table 3: Results for the 1-frame ahead prediction.
RMSE w/IF
RMSE wo/IF
Tc/Tcmin
Tc/Tcmin
Filter
Position [ m ]
Heading [ rad ]
Position [ m ]
Heading [ rad ]
w/IF
wo/IF
EKF
0.0234 b
0.2078
0.0478 b
0.2510
1.000
1.000
DD1
0.0548
0.1504
0.1232
0.1351
2.499
2.566
DD2
0.0658
0.1535
0.1232
0.1360 b
1.749
2.751
UKF
0.1187
0.0541
0.0617 c
0.2108
3.790
3.965
CDKF
0.0561
0.0325 a
0.0617
0.2115
3.594
3.756
Table 4: Results for the 4-frame ahead prediction.
RMSE w/IF
RMSE wo/IF
Tc/Tcmin
Tc/Tcmin
Filter
Position [ m ]
Heading [ rad ]
Position [ m ]
Heading [ rad ]
w/IF
wo/IF
EKF
0.0611 c
0.2138
0.0828 b
0.2577
1.000
1.000
DD1
0.0884
0.1541
0.0928
0.2145
2.220
2.261
DD2
0.0582 b
0.1373
0.0927 c
0.2143
2.210
2.261
UKF
0.0812
0.0784
0.1549
0.1402 c
3.874
4.024
CDKF
0.1208
0.0400 a
0.1549
0.1395 b
3.561
3.696
Table 5: Results for the 8-frame ahead prediction.
Figure 7: Noise-free reference trajectory.
Figure 8: Measured trajectory.
Figure 9: Predicted trajectory 4-frames ahead using the EKF without the IF.
Figure 10: Predicted trajectory 4-frames ahead using the EKF with the IF.
Figure 11: Predicted trajectory 4-frames ahead using the PF.
Figure 12: Trajectory components xw and yw of a real F-180 robot predicted 4-frames ahead using the EKF with the IF.
Robot trajectory tracking develops methods that make robots follow desired paths or motions accurately despite disturbances, uncertainty, and physical constraints.
Learning-based methods commonly treat state estimation in robotics as a sequence modeling problem. While this paradigm can be effective at maximizing end-to-end performance, models are often difficult to interpret and expensive to train, since training requires unrolling sequences of predictions in time. As an alternative to end-to-end trained state estimation, we propose a novel particle filtering algorithm in which models are trained from individual state transitions, fully exploiting the Markov property in robotic systems. In this framework, measurement models are learned implicitly by minimizing a denoising score matching objective. At inference, the learned denoiser is used alongside a (learned) dynamics model to approximately solve the Bayesian filtering equation at each time step, effectively guiding predicted states toward the data manifold informed by measurements. We evaluate the proposed method on challenging robotic state estimation tasks in simulation, demonstrating competitive performance compared to tuned end-to-end trained baselines. Importantly, our method offers the desirable composability of classical filtering algorithms, allowing prior information and external sensor models to be incorporated without retraining.
Lennart Röstel, Berthold Bäuml
Learning AI for Dextrous Robots Lab, Technical University of Munich, Germany.
This paper presents an implementation and evaluation of a Distributed Kalman--Consensus Filter (DKCF) for Multi-Object Tracking (MOT) in mobile robot networks operating under partial observability and heterogeneous localization uncertainty. A key challenge in such systems is the fusion of information from agents with differing localization quality, where frame misalignment can lead to inconsistent estimates, track duplication, and ghost tracks. To address this issue, we build upon the MOTLEE framework and retain its frame-alignment methodology, which uses consistently tracked dynamic objects as transient landmarks to improve relative pose estimates between robots. On top of this framework, we propose an uncertainty-aware adaptive consensus weighting mechanism that dynamically adjusts the influence of neighbor information based on the covariance of the transmitted estimates, thereby reducing the impact of unreliable data during distributed fusion. Local tracking is performed using a Kalman Filter (KF) with a Constant Velocity Model (CVM) and Global Nearest Neighbor (GNN) data association. simulation results demonstrate that adaptive weighting effectively protects local estimates from inconsistent data, yielding a MOTA improvement of 0.09 for agents suffering from localization drift, although system performance remains constrained by communication latency.
Niusha Khosravi, Rodrigo Ventura, Meysam Basiri
Instituto Superior Técnico University of Lisbon Lisbon, Portugal
Most trajectory forecasting models are trained on clean annotated histories, and are often evaluated under the same idealized assumption, although practical deployments rely on trajectories produced by imperfect multi-object trackers. The real-world observations exhibit localization jitter, missed or unstable detections, and data-association ambiguity, which are usually either ignored or removed through denoising. This paper instead treats tracking-derived reliability cues as an informative signal to be propagated to the predictor. We propose a plug-in uncertainty-aware formulation in which each observed state is encoded as an uncertain state representation, modeled by a Gaussian distribution whose covariance combines detection-level localization uncertainty and association-level ambiguity through the law of total variance. Existing backbones are adapted with minimal architectural changes: input trajectories are represented as Gaussian observations, and predicted trajectories are produced as Gaussian forecasts rather than deterministic coordinates. To train predictors that remain robust under structured observation noise, we combine temporally correlated Ornstein-Uhlenbeck perturbations with response-based knowledge distillation from a teacher trained on clean trajectories. Experiments on Oxford Town Centre and VIRAT using real tracker outputs, together with a complementary ETH/UCY pseudo-detection protocol, show that the proposed formulation improves displacement accuracy and the reliability-sharpness trade-off of probabilistic forecasts.
Stephane Da Silva Martins, Victor Petrovic, Emanuel Aldea +1
SATIE – CNRS UMR 8029, Université Paris-Saclay, France · ENS Paris-Saclay, Université Paris-Saclay, France