## Overview

• This visual SLAM benchmark is based on the FusionPortable dataset, which covers a variety of environments in The Hong Kong University of Science and Technology campus by utilizing multiple platforms for data collection. It provides a large range of difficult scenarios for Simultaneous Localization and Mapping (SLAM).
• All these sequences are characterized by structure-less areas and varying illumination conditions to best represent the real-world scenarios and pose great challenges to the SLAM algorithms which were verified in confined lab environments. Accurate centimeter-level ground truth of each sequence is provided for algorithm verification. Sensor data contained in the dataset includes 10Hz LiDAR point clouds, 20Hz stereo frame images, high-rate and asynchronous events from stereo event cameras, 200Hz acceleration and angular velocity readings from an IMU, and 10Hz GPS signals in the outdoor environments.
• Sensors are spatially and temporally calibrated.

## Hardware

• The sensors are mounted rigidly on an aluminium platform for handheld operation. An FPGA is utilized to generate an external signal trigger to synchronize clocks of all sensors. We install the sensor rig on various platforms to simulate distinguishable motions of different equipments, including a handheld device with a gimbal stabilizer, a quadruped robot, and an autonomous vehicle.
Sensor Characteristics
3D LiDAR (not provided) Ouster OS1-128, 128 channels, 120m range
Frame Camera * 2 FILR BFS-U3-31S4C， resolution: 1024 × 768
Event Camera * 2 DAVIS346, resolution: 346 × 240
IMU (body_imu) STIM300
GPS ZED-F9P RTK-GPS

• Calibration: The calibration file in yaml format can be downloaded here. We provide intrinsics & extrinsics of cameras as well as noise parameters of the IMU and also the raw calibration data. Intriniscs are calibrated using the MATLAB tool, and the extrinsics are calibrated using the Kalibr. Taking the frame_cam00.yaml as an example, parameters are provided in the form as follows:

image_width: 1024
image_height: 768
camera_name: stereo_left_flir_bfsu3
camera_matrix: !!opencv-matrix
rows: 3
cols: 3
dt: f
data: [ 6.05128601e+02, 0., 5.21453430e+02,
0., 6.04974060e+02, 3.94878479e+02,
0., 0., 1. ]
...
# extrinsics from the sensor (reference) to bodyimu (target)
quaternion_sensor_bodyimu: !!opencv-matrix
rows: 1
cols: 4
dt: f
data: [0.501677, 0.491365, -0.508060, 0.498754]  # (qw, qx, qy, qz)
translation_sensor_bodyimu: !!opencv-matrix
rows: 1
cols: 3
dt: f
data: [0.066447, -0.019381, -0.077907]
timeshift_sensor_bodyimu: 0.03497752745342453


Rotational and translational calibration parameters from the camera (reference frame) to the IMU (target frame) are presented in the form of the Hamilton quaternion ([qw, qx, qy, qz]) and the translation vector ([tx, ty, tz]). The timeshift is obtained by the Kalibr.

## Evaluation

• The submission will be ranked based on the completeness and frequency of the trajectory as well as on the position accuracy (ATE). The score is based on the ATE of individual points on the trajectory. Points with the error smaller than a distance threshold are added to your final score. This evaluation scheme is inspired by HILTI Challenge.

• Output trajectories should be transformed into the body_imu frame, We will align the trajectory with the dense ground truth points using a rigid transformation. Then the Absolute Trajectory Error (ATE) of a set of discrete point is computed. At each ground truth point, extra penalty points are added to the final score depending on the amount of error at this point:

Error Score (points)
<= 5cm 10
<= 30cm 6
<= 50cm 3
<= 100cm 1
> 100cm 0
• Each sequence will be evaluated over a maximum of 200 points, which leads to a maximum of $N\times 200$ points being evaluated among $N$ sequences.

Given an example:

## Submission Guidelines

• Trajectory Results

• Please upload a .zip file consisting of a list of text files named as the sequence name shown as follows:

20220215_canteen_night.txt
20220215_garden_night.txt
20220219_MCR_slow_00.txt
....

• The text files should have the following contents:

1644928761.036623716 0.0 0.0 0.0 0.0 0.0 0.0 1.0
....


Each row contains timestamp_s tx ty tz qx qy qz qw. The timestamps are in the unit of second which are used to establish temporal correspondences with the groundtruth. The first pose should be no later than the starting time specified above, and only poses after the starting time will be used for evaluation.

• The poses should specify the poses of the body IMU in the world frame. If the estimated poses are in the frame of other sensors, one should transform these poses into the world frame of the body IMU as T_bodyw_body = T_body_sensor * T_sensorw_sensor * T_body_sensor^(-1);.

• Do not publicly release your trajectory estimates, as we might re-use some of the datasets for future competitions.

## Sequence

Platform Sequence Compressed Bag
Handheld 20220216_canteen_night 15.9GB
20220216_canteen_day 17.0GB
20220215_garden_night 8.5GB
20220216_garden_day 20.4GB
20220216_corridor_day 27.4GB
20220216_escalator_day 31.7GB
20220225_building_day 37.5GB
20220216_MCR_slow 3.5GB
20220216_MCR_normal 2.2GB
20220216_MCR_fast 1.7GB
20220219_MCR_slow_01 8.4GB
20220219_MCR_normal_00 7.1GB
20220219_MCR_normal_01 6.5GB
20220219_MCR_fast_00 7.6GB
20220219_MCR_fast_01 8.5GB
• Detailed statistics are shown:

## FAQ

• How are the frames defined on the sensor setup?

The picture below is a schematic illustration of the reference frames (red = x, green = y, blue = z):

• How are the results scored?

The results submitted by each team will be scored based on the completeness and ATE accuracy of the trajectories. All the results will be displayed in the live leaderboard. Each trajectory will be scored based on the standard evaluation points, the accumulation of the scores of all these evaluation points is normalized to 100 points to get the final score of the sequence. Each evaluation point can get 0-10 points according to its accuracy.

• Will the organizer provide the calibration datasets of the IMU and camera?

Of course, we will provide the calibration data of IMU and cameras.

• Is the ground truth available?

We will provide some sample datasets along with their ground truth collected with the same sensor kit, but the ground truth for the challenge sequences is not available. However, you can submit your own results in the website evaluation system for evaluation.

## Reference

[1] Jianhao Jiao, Hexiang Wei, Tianshuai Hu, Xiangcheng Hu, etc., Lujia Wang, Ming Liu, FusionPortable: A Multi-Sensor Campus-Scene Dataset for Evaluation of Localization and Mapping Accuracy on Diverse Platforms, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2022, Kyoto, Japan.