IMAGE-BASED ORIENTATION DETERMINATION OF MOBILE SENSOR PLATFORMS

Abstract. Estimating the pose of a mobile robotic platform is a challenging task, especially when the pose needs to be estimated in a global or local reference frame and when the estimation has to be performed while the platform is moving. While the position of a platform can be measured directly via modern tachymetry or with the help of a global positioning service GNSS, the absolute platform orientation is harder to derive. Most often, only the relative orientation is estimated with the help of a sensor mounted on the robotic platform such as an IMU, with one or multiple cameras, with a laser scanner or with a combination of any of those. Then, a sensor fusion of the relative orientation and the absolute position is performed. In this work, an additional approach is presented: first, an image-based relative pose estimation with frames from a panoramic camera using a state-of-the-art visual odometry implementation is performed. Secondly, the position of the platform in a reference system is estimated using motorized tachymetry. Lastly, the absolute orientation is calculated using a visual marker, which is placed in the space, where the robotic platform is moving. The marker can be detected in the camera frame and since the position of this marker is known in the reference system, the absolute pose can be estimated. To improve the absolute pose estimation, a sensor fusion is conducted. Results with a Lego model train as a mobile platform show, that the trajectory of the absolute pose calculated independently with four different markers have a deviation < 0.66 degrees 50% of the time and that the average difference is < 1.17 degrees. The implementation is based on the popular Robotic Operating System ROS.

Download Full-text

2-DIMENSIONAL GEOMETRIC ANALYSIS OF A SIMPLE FREE NETWORK

ISPRS Annals of Photogrammetry Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-annals-v-4-2021-147-2021 ◽

2021 ◽

Vol V-4-2021 ◽

pp. 147-152

Author(s):

B. Sluis ◽

C. Toth

Keyword(s):

Reference System ◽

Geometric Analysis ◽

Relative Orientation ◽

Research Groups ◽

Local Reference System ◽

Local Reference ◽

Free Network ◽

Local Solutions ◽

Gauss Mixture ◽

Range Observation

Abstract. This paper attempts to quantify geometric considerations in observations and observe trends in solutions to free network solutions. The method of investigation will be utilizing 2D observations to determine how each measurement affects the overall solution and the location of the observations relative to the other nodes. A local reference system will be determined using the Gauss-Markov model with constraints by fixing the largest range observation to the y-axis to give a relative orientation. Further solutions will be calculated by fixing additional points to generate multiple least squares solutions relative to the local reference system. The resulting final points will be modeled using the Gauss-mixture model and compared to a simulated dataset generated by adding random error to the observations. Different weight matrices will be tested to demonstrate the effect on the overall solution. These methods were chosen because of prior experimentation by different research groups studying geometric considerations for UAS and ground surveying conditions. The major contribution will be the trends observed in the modeling and the correlation of the fixed local solutions to the geometry of the points.

Download Full-text

Multi-Sensor Fusion for Aerial Robots in Industrial GNSS-Denied Environments

Applied Sciences ◽

10.3390/app11093921 ◽

2021 ◽

Vol 11 (9) ◽

pp. 3921

Author(s):

Paloma Carrasco ◽

Francisco Cuesta ◽

Rafael Caballero ◽

Francisco J. Perez-Grau ◽

Antidio Viguria

Keyword(s):

Sensor Fusion ◽

Computational Efficiency ◽

Probabilistic Approach ◽

Laser Scanner ◽

Industrial Applications ◽

Experimental Results ◽

Added Value ◽

Aerial Robots ◽

3D Localization ◽

High Level

The use of unmanned aerial robots has increased exponentially in recent years, and the relevance of industrial applications in environments with degraded satellite signals is rising. This article presents a solution for the 3D localization of aerial robots in such environments. In order to truly use these versatile platforms for added-value cases in these scenarios, a high level of reliability is required. Hence, the proposed solution is based on a probabilistic approach that makes use of a 3D laser scanner, radio sensors, a previously built map of the environment and input odometry, to obtain pose estimations that are computed onboard the aerial platform. Experimental results show the feasibility of the approach in terms of accuracy, robustness and computational efficiency.

Download Full-text

Sensor fusion system to estimate the trajectory of a low cost mobile robotic platform using an Inertial Measurement Unit

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/138/1/012005 ◽

2016 ◽

Vol 138 ◽

pp. 012005

Author(s):

J.-S. Botero V. ◽

M. Rico G. ◽

J.-P. Villegas C

Keyword(s):

Sensor Fusion ◽

Inertial Measurement Unit ◽

Low Cost ◽

Measurement Unit ◽

Fusion System ◽

Robotic Platform ◽

Inertial Measurement

Download Full-text

A Moving 3D Laser Scanner for Automated Underbridge Inspection

10.20944/preprints201710.0172.v1 ◽

2017 ◽

Author(s):

Marco Tarabini ◽

Hermes Giberti ◽

Silvio Giancola ◽

Matteo Sgrenzaroli ◽

Remo Sala ◽

...

Keyword(s):

Measurement Uncertainty ◽

Numerical Simulations ◽

Relative Motion ◽

Reference System ◽

Complete System ◽

Laser Scanner ◽

Bridge Model ◽

Fixed Reference ◽

Scanning Head

Recent researches proved that the underbridge geometry can be reconstructed by mounting a 3D laser scanner on a motorized cart travelling on a walkway located under the bridge. The walkway is moved by a truck and the accuracy of the bridge model depends on the accuracy of the trajectory of the scanning head with respect to a fixed reference system. In this paper, we describe the metrological characterization of a method that uses non-contact systems to identify the relative motion of the cart with respect to the walkway; the orientation of the walkway with respect to the bridge is determined using inclinometers and optical rails, while the position of the truck with respect to the bridge is measured using a conventional odometer.  The measurement uncertainty of the proposed system was initially evaluated by numerical simulations and successively verified by experiments in laboratory conditions. The complete system has then been tested in operative conditions; the validity of the proposed approach has been demonstrated by comparing the geometry of buildings reconstructed with the proposed system with the geometry obtained with a static scan. Results evidenced that the errors are approximately 6 mm.

Download Full-text

HETEROGENEOUS MULTI-SENSOR FUSION FOR 2D AND 3D POSE ESTIMATION

10.37099/mtu.dc.etdr/420 ◽

2017 ◽

Author(s):

Hanieh Deilamsalehy

Keyword(s):

Sensor Fusion ◽

Pose Estimation ◽

3D Pose Estimation ◽

2D And 3D

Download Full-text

The Absolute Proper Motion of the Pleiades Cluster

International Astronomical Union Colloquium ◽

10.1017/s0252921100028001 ◽

1970 ◽

Vol 7 ◽

pp. 103-104

Author(s):

W. F. van Altena ◽

B. F. Jones

Keyword(s):

Northern Hemisphere ◽

Proper Motion ◽

Reference System ◽

The Absolute

The establishment of a truly inertial reference system is a problem that has defied solution for many years. However, with the completion of the Lick proper motion survey (Wright 1950) and the USSR program (Deutsch 1954) the situation for the northern hemisphere should be satisfactory.

Download Full-text