Journal
[1]
ALFA: A dataset for UAV fault and anomaly detection.
By Keipour, A., Mousaei, M. and Scherer, S.
In The International Journal of Robotics Researchvol. 40, no. 2-3, , pp. 515–520, 2021.
@inproceedings{keipour_mousaei_jrr21, author = {Keipour, Azarakhsh and Mousaei, Mohammadreza and Scherer, Sebastian}, title = {ALFA: A dataset for UAV fault and anomaly detection}, journal = {The International Journal of Robotics Research}, volume = {40}, number = {2-3}, pages = {515-520}, year = {2021}, tag = {journal}, doi = {10.1177/0278364920966642}, url = {https://doi.org/10.1177/0278364920966642}, eprint = {https://doi.org/10.1177/0278364920966642} }
We present a dataset of several fault types in control surfaces of a fixed-wing unmanned aerial vehicle (UAV) for use in fault detection and isolation (FDI) and anomaly detection (AD) research. Currently, the dataset includes processed data for 47 autonomous flights with 23 sudden full engine failure scenarios and 24 scenarios for 7 other types of sudden control surface (actuator) faults, with a total of 66 minutes of flight under normal conditions and 13 minutes of post-fault flight time. It additionally includes many hours of raw data of fully autonomous, autopilot-assisted and manual flights with tens of fault scenarios. The ground truth of the time and type of faults is provided in each scenario to enable evaluation of the methods using the dataset. We have also provided the helper tools in several programming languages to load and work with the data and to help the evaluation of a detection method using the dataset. A set of metrics is proposed to help to compare different methods using the dataset. Most of the current fault detection methods are evaluated in simulation and, as far as we know, this dataset is the only one providing the real flight data with faults in such capacity. We hope it will help advance the state of the art in AD or FDI research for autonomous aerial vehicles and mobile robots to enhance the safety of autonomous and remote flight operations further. The dataset and the provided tools can be accessed from https://doi.org/10.1184/R1/12707963.
Conference
[1]
Aerial Interaction with Tactile Sensing.
By Guo, X., He, G., Mousaei, M., Geng, J., Shi, G. and Scherer, S.
In 2024 IEEE International Conference on Robotics and Automation (ICRA), pp. 1576–1582, 2024.
@inproceedings{10611282, author = {Guo, Xiaofeng and He, Guanqi and Mousaei, Mohammadreza and Geng, Junyi and Shi, Guanya and Scherer, Sebastian}, booktitle = {2024 IEEE International Conference on Robotics and Automation (ICRA)}, title = {Aerial Interaction with Tactile Sensing}, year = {2024}, tag = {conference}, volume = {}, number = {}, pages = {1576-1582}, keywords = {Visualization;Accuracy;Tracking;Force;Pipelines;Tactile sensors;Real-time systems}, doi = {10.1109/ICRA57147.2024.10611282} }
While the field of autonomous Uncrewed Aerial Vehicles (UAVs) has grown rapidly, most applications only focus on passive visual tasks. Aerial interaction aims to execute tasks involving physical interactions, which offers a way to assist humans in high-altitude and high-risk operations. Tactile sensors, being both cost-effective and lightweight, are capable of sensing contact information including force distribution, as well as recognizing local textures. In this paper, we pioneer the use of vision-based tactile sensors on fully actuated UAVs in dynamic aerial manipulation tasks. We introduce a pipeline utilizing tactile feedback for force tracking via a hybrid motion-force controller and a method for wall texture detection during aerial interactions. Our experiments demonstrate that our system can effectively replace or complement traditional force/torque (F/T) sensors. Compared with only using the F/T sensor, our approach offers two solutions: substitution with tactile sensing, achieving comparable flight performance, or integration of tactile sensing with F/T sensor feedback, leading to around 16% improvement in position tracking accuracy. Our algorithm achieves 93.4% accuracy in real-time texture recognition, which further escalates to 100% in post-contact analysis. To the best of our knowledge, this is the first work to incorporate a vision-based tactile sensor into aerial interaction tasks.
[2]
How is the Pilot Doing: VTOL Pilot Workload Estimation by Multimodal Machine Learning on Psycho-physiological Signals.
By Park, J.H., Chen, L., Higgins, I., Zheng, Z., Mehrotra, S., Salubre, K., Mousaei, M., Willits, S., Levedahl, B., Buker, T., Xing, E., Misu, T., Scherer, S. and Oh, J.
In 2024 33rd IEEE International Conference on Robot and Human Interactive Communication (ROMAN), pp. 2311–2318, 2024.
@inproceedings{10731202, author = {Park, Jong Hoon and Chen, Lawrence and Higgins, Ian and Zheng, Zhaobo and Mehrotra, Shashank and Salubre, Kevin and Mousaei, Mohammadreza and Willits, Steven and Levedahl, Blaine and Buker, Timothy and Xing, Eliot and Misu, Teruhisa and Scherer, Sebastian and Oh, Jean}, booktitle = {2024 33rd IEEE International Conference on Robot and Human Interactive Communication (ROMAN)}, title = {How is the Pilot Doing: VTOL Pilot Workload Estimation by Multimodal Machine Learning on Psycho-physiological Signals}, year = {2024}, volume = {}, number = {}, tag = {conference}, pages = {2311-2318}, keywords = {Accuracy;Time series analysis;Estimation;Training data;Machine learning;Predictive models;Transformers;Robot sensing systems;Aircraft;Monitoring}, doi = {10.1109/RO-MAN60168.2024.10731202} }
Vertical take-off and landing (VTOL) aircraft do not require a prolonged runway, thus allowing them to land almost anywhere. In recent years, their flexibility has made them popular in development, research, and operation. When compared to traditional fixed-wing aircraft and rotorcraft, VTOLs bring unique challenges as they combine many maneuvers from both types of aircraft. Pilot workload is a critical factor for safe and efficient operation of VTOLs. In this work, we conduct a user study to collect multimodal data from 28 pilots while they perform a variety of VTOL flight tasks. We analyze and interpolate behavioral patterns related to their performance and perceived workload. Finally, we build machine learning models to estimate their workload from the collected data. Our results are promising, suggesting that quantitative and accurate VTOL pilot workload monitoring is viable. Such assistive tools would help the research field understand VTOL operations and serve as a stepping stone for the industry to ensure VTOL safe operations and further remote operations.
[3]
A Unified MPC Strategy for a Tilt-rotor VTOL UAV Towards Seamless Mode Transitioning.
By Chen, Q., Hu, Z., Geng, J., Bai, D., Mousaei, M. and Scherer, S.
In AIAA SCITECH 2024,
2024
@inbook{doi:10.2514/6.2024-2878, author = {Chen, Qizhao and Hu, Ziqi and Geng, Junyi and Bai, Dongwei and Mousaei, Mohammadreza and Scherer, Sebastian}, title = {A Unified MPC Strategy for a Tilt-rotor VTOL UAV Towards Seamless Mode Transitioning}, booktitle = {AIAA SCITECH 2024}, chapter = {}, pages = {}, year = {2024}, tag = {conference}, doi = {10.2514/6.2024-2878}, url = {https://arc.aiaa.org/doi/abs/10.2514/6.2024-2878}, eprint = {https://arc.aiaa.org/doi/pdf/10.2514/6.2024-2878} }
Capabilities of long-range flight and vertical take-off and landing (VTOL) are essential for Urban Air Mobility (UAM). Tiltrotor VTOLs have the advantage of balancing control simplicity and system complexity due to their redundant control authority. Prior work on controlling these aircraft either requires separate controllers and switching modes for different vehicle configurations or performs the control allocation on separate actuator sets, which cannot fully use the potential of the redundancy of tiltrotor. This paper introduces a unified MPC-based control strategy for a customized tiltrotor VTOL Unmanned Aerial Vehicle (UAV), which does not require mode-switching and can perform the control allocation in a consistent way. The incorporation of four independently controllable rotors in VTOL design offers an extra level of redundancy, allowing the VTOL to accommodate actuator failures. The result shows that our approach outperforms PID controllers while maintaining unified control. It allows the VTOL to perform smooth acceleration/deceleration, and precise coordinated turns. In addition, the independently controlled tilts enable the vehicle to handle actuator failures, ensuring that the aircraft remains operational even in the event of a servo or motor malfunction.
[4]
Flying Calligrapher: Contact-Aware Motion and Force Planning and Control for Aerial Manipulation.
By Guo, X., He, G., Xu, J., Mousaei, M., Geng, J., Scherer, S. and Shi, G.
In IEEE Robotics and Automation Letters, vol. 9, no. 12, pp. 11194–11201, 2024.
@article{10733990, author = {Guo, Xiaofeng and He, Guanqi and Xu, Jiahe and Mousaei, Mohammadreza and Geng, Junyi and Scherer, Sebastian and Shi, Guanya}, journal = {IEEE Robotics and Automation Letters}, title = {Flying Calligrapher: Contact-Aware Motion and Force Planning and Control for Aerial Manipulation}, year = {2024}, volume = {9}, number = {12}, tag = {conference}, pages = {11194-11201}, keywords = {Force;Trajectory;End effectors;Target tracking;Touch sensitive screens;Planning;Autonomous aerial vehicles;Trajectory planning;Pipelines;Manipulator dynamics;Aerial systems: applications;aerial systems: mechanics and control;integrated planning and control}, doi = {10.1109/LRA.2024.3486236} }
Aerial manipulation has gained interest in completing high-altitude tasks that are challenging for human workers, such as contact inspection and defect detection, etc. Previous research has focused on maintaining static contact points or forces. This letter addresses a more general and dynamic task: simultaneously tracking time-varying contact force in the surface normal direction and motion trajectories on tangential surfaces. We propose a pipeline that includes a contact-aware trajectory planner to generate dynamically feasible trajectories, and a hybrid motion-force controller to track such trajectories. We demonstrate the approach in an aerial calligraphy task using a novel sponge pen design as the end-effector, whose stroke width is positively related to the contact force. Additionally, we develop a touchscreen interface for flexible user input. Experiments show our method can effectively draw diverse letters, achieving an IoU of 0.59 and an end-effector position (force) tracking RMSE of 2.9 cm (0.7N).
[5]
Image-Based Visual Servo Control for Aerial Manipulation Using a Fully-Actuated UAV.
By He, G., Jangir, Y., Geng, J., Mousaei, M., Bai, D. and Scherer, S.
In 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 5042–5049, 2023.
@inproceedings{10342145, author = {He, Guanqi and Jangir, Yash and Geng, Junyi and Mousaei, Mohammadreza and Bai, Dongwei and Scherer, Sebastian}, booktitle = {2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)}, title = {Image-Based Visual Servo Control for Aerial Manipulation Using a Fully-Actuated UAV}, year = {2023}, volume = {}, number = {}, tag = {conference}, pages = {5042-5049}, keywords = {Bridges;Visualization;Simultaneous localization and mapping;Tracking;Force;Autonomous aerial vehicles;End effectors}, doi = {10.1109/IROS55552.2023.10342145} }
Using Unmanned Aerial Vehicles (UAVs) to per-form high-altitude manipulation tasks beyond just passive visual application can reduce the time, cost, and risk of human workers. Prior research on aerial manipulation has relied on either ground truth state estimate or GPS/total station with some Simultaneous Localization and Mapping (SLAM) algorithms, which may not be practical for many applications close to infrastructure with degraded GPS signal or featureless environments. Visual servo can avoid the need to estimate robot pose. Existing works on visual servo for aerial manipulation either address solely end-effector position control or rely on precise velocity measurement and pre-defined visual visual marker with known pattern. Furthermore, most of previous work used under-actuated UAVs, resulting in complicated mechanical and hence control design for the end-effector. This paper develops an image-based visual servo control strategy for bridge maintenance using a fully-actuated UAV. The main components are (1) a visual line detection and tracking system, (2) a hybrid impedance force and motion control system. Our approach does not rely on either robot pose/velocity estimation from an external localization system or pre-defined visual markers. The complexity of the mechanical system and controller architecture is also minimized due to the fully-actuated nature. Experiments show that the system can effectively execute motion tracking and force holding using only the visual guidance for the bridge painting. To the best of our knowledge, this is one of the first studies on aerial manipulation using visual servo that is capable of achieving both motion and force control without the need of external pose/velocity information or pre-defined visual guidance.
[6]
UAS Simulator for Modeling, Analysis and Control in Free Flight and Physical Interaction.
By Keipour, A., Mousaei, M., Geng, J., Bai, D. and Scherer, S.
In AIAA SCITECH 2023,
2023
@inbook{doi:10.2514/6.2023-1279, author = {Keipour, Azarakhsh and Mousaei, Mohammadreza and Geng, Junyi and Bai, Dongwei and Scherer, Sebastian}, title = {UAS Simulator for Modeling, Analysis and Control in Free Flight and Physical Interaction}, booktitle = {AIAA SCITECH 2023}, chapter = {}, tag = {conference}, pages = {}, year = {2023}, doi = {10.2514/6.2023-1279}, url = {https://arc.aiaa.org/doi/abs/10.2514/6.2023-1279}, eprint = {https://arc.aiaa.org/doi/pdf/10.2514/6.2023-1279} }
View Video Presentation: https://doi.org/10.2514/6.2023-1279.vid This paper presents the ARCAD simulator for the rapid development of Unmanned Aerial Systems (UAS), including underactuated and fully-actuated multirotors, fixed-wing aircraft, and Vertical Take-Off and Landing (VTOL) hybrid vehicles. The simulator is designed to accelerate these aircraft’s modeling and control design. It provides various analyses of the design and operation, such as wrench-set computation, controller response, and flight optimization. In addition to simulating free flight, it can simulate the physical interaction of the aircraft with its environment. The simulator is written in MATLAB to allow rapid prototyping and is capable of generating graphical visualization of the aircraft and the environment in addition to generating the desired plots. It has been used to develop several real-world multirotor and VTOL applications. The source code is available at https://github.com/keipour/aircraft-simulator-matlab.
[7]
Design, Modeling and Control for a Tilt-rotor VTOL UAV in the Presence of Actuator Failure.
By Mousaei, M., Geng, J., Keipour, A., Bai, D. and Scherer, S.
In 2022 International Conference on Robotics and Automation (ICRA), 2022.
@article{mousaei2022design, title = {Design, Modeling and Control for a Tilt-rotor VTOL UAV in the Presence of Actuator Failure}, author = {Mousaei, Mohammadreza and Geng, Junyi and Keipour, Azarakhsh and Bai, Dongwei and Scherer, Sebastian}, journal = {2022 International Conference on Robotics and Automation (ICRA)}, year = {2022}, tag = {conference}, url = {https://arxiv.org/abs/2205.05533} }
Enabling vertical take-off and landing while pro- viding the ability to fly long ranges opens the door to a wide range of new real-world aircraft applications while improving many existing tasks. Tiltrotor vertical take-off and landing (VTOL) unmanned aerial vehicles (UAVs) are a better choice than fixed-wing and multirotor aircraft for such applications. Prior works on these aircraft have addressed the aerodynamic performance, design, modeling, and control. However, a less ex- plored area is the study of their potential fault tolerance due to their inherent redundancy, which allows them to tolerate some degree of actuation failure. This paper introduces tolerance to several types of actuator failures in a tiltrotor VTOL aircraft. We discuss the design and modeling of a custom tiltrotor VTOL UAV, which is a combination of a fixed-wing aircraft and a quadrotor with tilting rotors, where the four propellers can be rotated individually. Then, we analyze the feasible wrench space the vehicle can generate and design the dynamic control allocation so that the system can adapt to actuator failures, benefiting from the configuration redundancy. The proposed approach is lightweight and is implemented as an extension to an already-existing flight control stack. Extensive experiments validate that the system can maintain the controlled flight under different actuator failures. This work is the first study of the tiltrotor VTOL’s fault-tolerance that exploits the configuration redundancy to the best of our knowledge.
[8]
Integration of Fully-Actuated Multirotors into Real-World Applications.
By Keipour, A., Mousaei, M., Ashley, A.T. and Scherer, S.
In arXiv preprint arXiv:2011.06666, 2020.
@article{keipour_mousaei_2020integration, title = {Integration of Fully-Actuated Multirotors into Real-World Applications}, author = {Keipour, Azarakhsh and Mousaei, Mohammadreza and Ashley, Andrew T and Scherer, Sebastian}, journal = {arXiv preprint arXiv:2011.06666}, tag = {conference}, url = {https://arxiv.org/abs/2011.06666}, year = {2020} }
The introduction of fully-actuated multirotors has opened the door to new possibilities and more efficient solutions to many real-world applications. However, their integration had been slower than expected, partly due to the need for new tools to take full advantage of these robots. As far as we know, all the groups currently working on the fully-actuated multirotors develop new full-pose (6-D) tools and methods to use their robots, which is inefficient, time- consuming, and requires many resources. We propose a way of bridging the gap between the tools already available for underactuated robots and the new fully- actuated vehicles. The approach can extend the existing under- actuated flight controllers to support the fully-actuated robots, or enhance the existing fully-actuated controllers to support existing underactuated flight stacks. We introduce attitude strategies that work with the underactuated controllers, tools, planners and remote control interfaces, all while allowing taking advantage of the full actuation. Moreover, new methods are proposed that can properly handle the limited lateral thrust suffered by many fully-actuated UAV designs. The strategies are lightweight, simple, and allow rapid integration of the available tools with these new vehicles for the fast development of new real-world applications.
[9]
Automatic Real-time Anomaly Detection for Autonomous Aerial Vehicles.
By Keipour, A., Mousaei, M. and Scherer, S.
In 2019 International Conference on Robotics and Automation (ICRA), pp. 5679–5685, 2019.
@inproceedings{keipour_mousaei_icra19, author = {Keipour, Azarakhsh and Mousaei, Mohammadreza and Scherer, Sebastian}, booktitle = {2019 International Conference on Robotics and Automation (ICRA)}, title = {Automatic Real-time Anomaly Detection for Autonomous Aerial Vehicles}, year = {2019}, volume = {}, number = {}, pages = {5679-5685}, tag = {conference}, doi = {10.1109/ICRA.2019.8794286}, url = {https://ieeexplore.ieee.org/abstract/document/8794286} }
The recent increase in the use of aerial vehicles raises concerns about the safety and reliability of autonomous operations. There is a growing need for methods to monitor the status of these aircraft and report any faults and anomalies to the safety pilot or to the autopilot to deal with the emergency situation. In this paper, we present a real-time approach using the Recursive Least Squares method to detect anomalies in the behavior of an aircraft. The method models the relationship between correlated input-output pairs online and uses the model to detect the anomalies. The result is an easy-to-deploy anomaly detection method that does not assume a specific aircraft model and can detect many types of faults and anomalies in a wide range of autonomous aircraft. The experiments on this method show a precision of 88.23%, recall of 88.23% and 86.36% accuracy for over 22 flight tests. The other contribution is providing a new fault detection open dataset for autonomous aircraft, which contains complete data and the ground truth for 22 fixed-wing flights with eight different types of mid-flight actuator failures to help future fault detection research for aircraft.
[10]
Automated Analysis, Reporting, and Archiving for Robotic Nondestructive Assay of Holdup Deposits.
By Jones, H., Maley, S., Yonekawa, K., Mousaei, M., Yesso, J.D., Kohanbash, D. and Whittaker, W.
In arXiv preprint arXiv:1901.10795, 2019.
@article{jones_mousaei_wm19, title = {Automated Analysis, Reporting, and Archiving for Robotic Nondestructive Assay of Holdup Deposits}, author = {Jones, Heather and Maley, Siri and Yonekawa, Kenji and Mousaei, Mohammadreza and Yesso, J David and Kohanbash, David and Whittaker, William}, journal = {arXiv preprint arXiv:1901.10795}, tag = {conference}, url = {https://arxiv.org/abs/1901.10795}, year = {2019} }
To decommission deactivated gaseous diffusion enrichment facilities, miles of contaminated pipe must be measured. The current method requires thousands of manual measurements, repeated manual data transcription, and months of manual analysis. The Pipe Crawling Activity Measurement System (PCAMS), developed by Carnegie Mellon University and in commissioning for use at the DOE Portsmouth Gaseous Diffusion Enrichment Facility, uses a robot to measure Uranium-235 from inside pipes and automatically log the data. Radiation measurements, as well as imagery, geometric modeling, and precise measurement positioning data are digitally transferred to the PCAMS server. On the server, data can be automatically processed in minutes and summarized for analyst review. Measurement reports are auto-generated with the push of a button. A database specially-configured to hold heterogeneous data such as spectra, images, and robot trajectories serves as archive. This paper outlines the features and design of the PCAMS Post-Processing Software, currently in commissioning for use at the Portsmouth Gaseous Diffusion Enrichment Facility. The analysis process, the analyst interface to the system, and the content of auto-generated reports are each described. Example pipe-interior geometric surface models, illustration of how key report features apply in operational runs, and user feedback are discussed.
[11]
A robot for nondestructive assay of holdup deposits in gaseous diffusion piping.
By Jones, H., Maley, S., Mousaei, M., Kohanbash, D., Whittaker, W., Teza, J., Zhang, A., Jog, N. and Whittaker, W.
In arXiv preprint arXiv:1901.10341, 2019.
@article{jones_mousaei_wm19robot, title = {A robot for nondestructive assay of holdup deposits in gaseous diffusion piping}, author = {Jones, Heather and Maley, Siri and Mousaei, Mohammadreza and Kohanbash, David and Whittaker, Warren and Teza, James and Zhang, Andrew and Jog, Nikhil and Whittaker, William}, journal = {arXiv preprint arXiv:1901.10341}, tag = {conference}, url = {https://arxiv.org/abs/1901.10341}, year = {2019} }
Miles of contaminated pipe must be measured, foot by foot, as part of the decommissioning effort at deactivated gaseous diffusion enrichment facilities. The current method requires cutting away asbestos-lined thermal enclosures and performing repeated, elevated operations to manually measure pipe from the outside. The RadPiper robot, part of the Pipe Crawling Activity Measurement System (PCAMS) developed by Carnegie Mellon University and commissioned for use at the DOE Portsmouth Gaseous Diffusion Enrichment Facility, automatically measures U-235 in pipes from the inside. This improves certainty, increases safety, and greatly reduces measurement time. The heart of the RadPiper robot is a sodium iodide scintillation detector in an innovative disc-collimated assembly. By measuring from inside pipes, the robot significantly increases its count rate relative to external through-pipe measurements. The robot also provides imagery, models interior pipe geometry, and precisely measures distance in order to localize radiation measurements. Data collected by this system provides insight into pipe interiors that is simply not possible from exterior measurements, all while keeping operators safer. This paper describes the technical details of the PCAMS RadPiper robot. Key features for this robot include precision distance measurement, in-pipe obstacle detection, ability to transform for two pipe sizes, and robustness in autonomous operation. Test results demonstrating the robot’s functionality are presented, including deployment tolerance tests, safeguarding tests, and localization tests. Integrated robot tests are also shown.
[12]
Optimizing pilot overhead for ultra-reliable short-packet transmission.
By Mousaei, M. and Smida, B.
In 2017 IEEE International Conference on Communications (ICC), pp. 1–5, 2017.
@inproceedings{mousaei_icc17, author = {Mousaei, Mohammadreza and Smida, Besma}, booktitle = {2017 IEEE International Conference on Communications (ICC)}, title = {Optimizing pilot overhead for ultra-reliable short-packet transmission}, year = {2017}, volume = {}, number = {}, pages = {1-5}, tag = {conference}, doi = {10.1109/ICC.2017.7996416}, url = {https://ieeexplore.ieee.org/abstract/document/7996416} }
In this paper we optimize the pilot overhead for ultra-reliable short-packet transmission and investigate the de- pendence of this overhead on packet size and error probability. In particular, we consider a point-to-point communication in which one sensor sends messages to a central node, or base-station, over AWGN with Rayleigh fading channel. We formalize the optimization in terms of approximate achievable rates at a given block length, pilot length, and error probability. This leads to more accurate pilot overhead optimization. Simulation results show that it is important to take into account the packet size and the error probability when optimizing the pilot overhead.
[13]
ComSens: Exploiting pilot diversity for pervasive integration of communication and sensing in MIMO-TDD-Frameworks.
By Mousaei, M., Soltanalian, M. and Smida, B.
In MILCOM 2017 - 2017 IEEE Military Communications Conference (MILCOM), pp. 617–622, 2017.
@inproceedings{mousaei_milcom17, author = {Mousaei, Mohammadreza and Soltanalian, Mojtaba and Smida, Besma}, booktitle = {MILCOM 2017 - 2017 IEEE Military Communications Conference (MILCOM)}, title = {ComSens: Exploiting pilot diversity for pervasive integration of communication and sensing in MIMO-TDD-Frameworks}, year = {2017}, volume = {}, tag = {conference}, number = {}, pages = {617-622}, doi = {10.1109/MILCOM.2017.8170851}, url = {https://ieeexplore.ieee.org/abstract/document/8170851} }
In this paper, we propose a fully-integrated radar and communication system - named ComSens. We utilize two different pilot sequences (one for uplink and one for downlink) with the condition that they must be uncorrelated to each other. Within such a framework, the signal received from end-user and the back-scattered signal from the desired objects have uncorrelated pilots. Thus, the base-station is able to distinguish data signal from user and back-scattered signal from object. We assume a time division duplex (TDD) framework. The pilot sequences are designed for MIMO channels. We evaluate channel MSE as a figure of merit for communication system. We also show that the designed pilots are uncorrelated for a range of time lags. Moreover, designed uplink pilot has negligable autocorrelation for a range of time lags leading to an impulse-like autocorrelation for radar sensing.
Workshop
[1]
A Simulator for Fully-Actuated UAVs.
By Keipour, A., Mousaei, M. and Scherer, S.
In 2023 International Conference on Robotics and Automation (ICRA), 2023.
@article{keipour2023simulatorfullyactuateduavs, title = {A Simulator for Fully-Actuated UAVs}, author = {Keipour, Azarakhsh and Mousaei, Mohammadreza and Scherer, Sebastian}, journal = {2023 International Conference on Robotics and Automation (ICRA)}, year = {2023}, tag = {workshop}, url = {https://arxiv.org/abs/2305.07228} }
This workshop paper presents the challenges we encountered when simulating fully-actuated Unmanned Aerial Vehicles (UAVs) for our research and the solutions we developed to overcome the challenges. We describe the ARCAD simula- tor that has helped us rapidly implement and test different controllers ranging from Hybrid Force-Position Controllers to advanced Model Predictive Path Integrals and has allowed us to analyze the design and behavior of different fully- actuated UAVs. We used the simulator to enable real-world deployments of our fully-actuated UAV fleet for different applications. The simulator is further extended to support the physical interaction of UAVs with their environment and allow more UAV designs, such as hybrid VTOLs. The code for the simulator can be accessed from https://github.com/ keipour/aircraft-simulator-matlab.
[2]
VTOL Failure Detection and Recovery by Utilizing Redundancy.
By Mousaei, M., Keipour, A., Geng, J. and Scherer, S.
In 2022 International Conference on Robotics and Automation (ICRA), 2022.
@article{mousaei_icra22vtol, title = {VTOL Failure Detection and Recovery by Utilizing Redundancy}, author = {Mousaei, Mohammadreza and Keipour, Azarakhsh and Geng, Junyi and Scherer, Sebastian}, journal = {2022 International Conference on Robotics and Automation (ICRA)}, year = {2022}, tag = {workshop}, url = {https://arxiv.org/abs/2206.00588} }
Offering vertical take-off and landing (VTOL) capabilities and the ability to travel great distances are crucial for Urban Air Mobility (UAM) vehicles. These capabilities make hybrid VTOLs the clear front-runners among UAM platforms. On the other hand, concerns regarding the safety and reliability of autonomous aircraft have grown in response to the recent growth in aerial vehicle usage. As a result, monitoring the aircraft status to report any failures and recovering to prevent the loss of control when a failure happens are becoming increasingly important. Hybrid VTOLs can withstand some de- gree of actuator failure due to their intrinsic redundancy. Their aerodynamic performance, design, modeling, and control have all been addressed in the previous studies. However, research on their potential fault tolerance is still a less investigated field. In this workshop, we will present a summary of our work on aircraft fault detection and the recovery of our hybrid VTOL. First, we will go over our real-time aircraft-independent system for detecting actuator failures and abnormal behaviors. Then, in the context of our custom tiltrotor VTOL aircraft design, we talk about our optimization-based control allocation system, which utilizes the vehicle’s configuration redundancy to recover from different actuation failures. Finally, we explore the ideas of how these parts can work together to provide a fail-safe system. We present our simulation and real-life experiments.
[3]
Detection and Physical Interaction with Deformable Linear Objects.
By Keipour, A., Mousaei, M., Bandari, M., Schaal, S. and Scherer, S.
In 2022 International Conference on Robotics and Automation (ICRA), 2022.
@article{keipour_mousaei_icra22detection, title = {Detection and Physical Interaction with Deformable Linear Objects}, author = {Keipour, Azarakhsh and Mousaei, Mohammadreza and Bandari, Maryam and Schaal, Stefan and Scherer, Sebastian}, journal = {2022 International Conference on Robotics and Automation (ICRA)}, year = {2022}, tag = {workshop}, url = {https://arxiv.org/abs/2205.08041} }
Deformable linear objects (e.g., cables, ropes, and threads) commonly appear in our everyday lives. However, perception of these objects and the study of physical interaction with them is still a growing area. There have already been successful methods to model and track deformable linear objects. However, the number of methods that can automatically extract the initial conditions in non-trivial situations for these methods has been limited, and they have been introduced to the community only recently. On the other hand, while physical interaction with these objects has been done with ground manipulators, there have not been any studies on physical interaction and manipulation of the deformable linear object with aerial robots. This workshop describes our recent work on detecting deformable linear objects, which uses the segmentation output of the existing methods to provide the initialization required by the tracking methods automatically. It works with crossings and can fill the gaps and occlusions in the segmentation and output the model desirable for physical interaction and simulation. Then we present our work on using the method for tasks such as routing and manipulation with the ground and aerial robots. We discuss our feasibility analysis on extending the physical interaction with these objects to aerial manipulation applications.
MS Thesis
[1]
Efficient Use of Spectral Resources in Wireless Communication Using Training Data Optimization.
By Mousaei, M.
In arXiv preprint arXiv:1903.12259, 2019.
@article{mousaei2019msthesis, title = {Efficient Use of Spectral Resources in Wireless Communication Using Training Data Optimization}, author = {Mousaei, Mohammadreza}, journal = {arXiv preprint arXiv:1903.12259}, year = {2019}, tag = {msthesis}, url = {https://arxiv.org/abs/1903.12259} }
Wireless communication applications has acquired a vastly increasing range over the past decade. This rapidly increasing demand implies limitations on utilizing wireless resources. One of the most important resources in wireless communication is frequency spectrum. This thesis provides different solutions towards increasing the spectral efficiency. The first solution provided in this thesis is to use a more accurate optimization metric: maximal acheivable rate (compared to traditional metric: ergodic capacity) to optimize training data size in wireless communication. Training data symbols are previously known symbols to the receiver inserted in data packets which are used by receiver to acquire channel state information (CSI). Optimizing training data size with respect to our proposed tight optimization metric, we could achieve higher rates especially for short packet and ultra reliable applications. Our second proposed solution to increase spectral efficiency is to design a multifunction communication and sensing platform utilizing a special training sequence design. We proposed a platform where two training sequences are designed, one for the base-station and the other for the user. By designing these two training sequence such that they are uncorrelated to each other, the base station will be able to distinguish between the two training sequence. Having one of the sequences especially designed for radar purposes (by designing it such that it has an impulse-like autocorrelation), the system will be able to sense the environment, transmit and receive the communication data simultaneously.