Pushbroom Stereo for High-Speed Navigation in Cluttered Environments

We present a novel stereo vision algorithm that is capable of obstacle detection on a mobile-CPU processor at 120 frames per second. Our system performs a subset of standard block-matching stereo processing, searching only for obstacles at a single depth. By using an onboard IMU and state-estimator, we can recover the position of obstacles at all other depths, building and updating a full depth-map at framerate. Here, we describe both the algorithm and our implementation on a high-speed, small UAV, flying at over 20 MPH (9 m/s) close to obstacles. The system requires no external sensing or computation and is, to the best of our knowledge, the first high-framerate stereo detection system running onboard a small UAV

Debugging Quadrocopter Trajectories in Mixed Reality

Debugging and monitoring robotic applications is a very intricate and error-prone task. To this end, we propose a mixed-reality approach to facilitate this process along a concrete scenario. We connected the Microsoft HoloLens smart glass to the Robot Operating System (ROS), which is used to control robots, and visualize arbitrary flight data of a quadrocopter. Hereby, we display holograms correctly in the real world based on a conversion of the internal tracking coordinates into coordinates provided by a motion capturing system. Moreover, we describe the synchronization process of the internal tracking with the motion capturing. Altogether, the combination of the HoloLens and the external tracking system shows promising preliminary results. Moreover, our approach can be extended to directly manipulate source code through its mixed-reality visualization and offers new interaction methods to debug and develop robotic applications

Decentralized collaborative transport of fabrics using micro-UAVs

Small unmanned aerial vehicles (UAVs) have generally little capacity to carry payloads. Through collaboration, the UAVs can increase their joint payload capacity and carry more significant loads. For maximum flexibility to dynamic and unstructured environments and task demands, we propose a fully decentralized control infrastructure based on a swarm-specific scripting language, Buzz. In this paper, we describe the control infrastructure and use it to compare two algorithms for collaborative transport: field potentials and spring-damper. We test the performance of our approach with a fleet of micro-UAVs, demonstrating the potential of decentralized control for collaborative transport.Comment: Submitted to 2019 International Conference on Robotics and Automation (ICRA). 6 page

AR.Drone UAV control parameters tuning based on particle swarm optimization algorithm

In this paper, a proposed particle swarm optimization called multi-objective particle swarm optimization (MOPSO) with an accelerated update methodology is employed to tune Proportional-Integral-Derivative (PID) controller for an AR.Drone quadrotor. The proposed approach is to modify the velocity formula of the general PSO systems in order for improving the searching efficiency and actual execution time. Three PID control parameters, i.e., the proportional gain K-p, integral gain K-i and derivative gain K-d are required to form a parameter vector which is considered as a particle of PSO. To derive the optimal PID parameters for the Ar.Drone, the modified update method is employed to move the positions of all particles in the population. In the meanwhile, multi-objective functions defined for PID controller optimization problems are minimized. The results verify that the proposed MOPSO is able to perform appropriately in Ar.Drone control system

Impedance control of a planar quadrotor with an extended Kalman filter external wrench estimator

In this work we deal with the non-linear control of aerial vehicles under external disturbances. We develop a non-linear velocity controller able to accommodate estimations of the external disturbing forces and moments. To estimate the external actions and at the same time provide improvements on the state estimation we make use of the EKF approach. Finally, we present simulations comparing close loop performance of a system with the proposed methodology implemented against close loop performance of the same controller but without the estimation of the external forces.Postprint (published version

Mechanical Design, Modelling and Control of a Novel Aerial Manipulator

In this paper a novel aerial manipulation system is proposed. The mechanical structure of the system, the number of thrusters and their geometry will be derived from technical optimization problems. The aforementioned problems are defined by taking into consideration the desired actuation forces and torques applied to the end-effector of the system. The framework of the proposed system is designed in a CAD Package in order to evaluate the system parameter values. Following this, the kinematic and dynamic models are developed and an adaptive backstepping controller is designed aiming to control the exact position and orientation of the end-effector in the Cartesian space. Finally, the performance of the system is demonstrated through a simulation study, where a manipulation task scenario is investigated.Comment: Comments: 8 Pages, 2015 IEEE International Conference on Robotics and Automation (ICRA '15), Seattle, WA, US

Detection and estimation of moving obstacles for a UAV

In recent years, research interest in Unmanned Aerial Vehicles (UAVs) has been grown rapidly because of their potential use for a wide range of applications. In this paper, we proposed a vision-based detection and position/velocity estimation of moving obstacle for a UAV. The knowledge of a moving obstacle's state, i.e., position, velocity, is essential to achieve better performance for an intelligent UAV system specially in autonomous navigation and landing tasks. The novelties are: (1) the design and implementation of a localization method using sensor fusion methodology which fuses Inertial Measurement Unit (IMU) signals and Pozyx signals; (2) The development of detection and estimation of moving obstacles method based on on-board vision system. Experimental results validate the effectiveness of the proposed approach. (C) 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved

Pengaruh Latihan Kekuatan Otot Lengan Terhadap Kemampuan Tembakan Hukuman (Free Throw) Dalam Permainan Bola Basket Putra Club Adhyaksa Kepahiang: The Effect of Arm Muscle Strength Training on Free Throws in the Men's Basketball Game Club Adhyaksa Kepahiang

Penelitian ini bertujuan untuk mengetahui pengaruh latihan kekuatan otot lengan terhadap tembakan hukuman (free throw) dalam permainan bola basket club adhyaksa kepahiang. Jenis penelitian ini adalah kuantitatif. Populasi dalam penelitian ini adalah atlet bola basketclub adhyaksa yng berjumlah 55 atlet. Desain penelitian yang digunakan adalah one-group pretest-posttest. Teknik pengambilan sampel yng digunakan tersebut adalah proposive sampling. Dengan demikian jumlah sampel dalam penelitian ini adalah sebanyak 20 atlet basket putra club Adhyaksa Kepahiang. Perlakuan yang diberikan yaitu Latihan Kekuatan Otot Lengan yng terdiri dari latihan Squat Thrust, Latihan lempar tangkap bola dan latihan pull up. Teknik pengumpulan data dalam penelitian ini dengan metode tes secara langsung yaitu menggunakan tes tembakan hukuman (Free Throw) selama 1 menit . Uji persyarat statistik memenuhi syarat homogen dan data berdistribusi normal berdasarkan hitungan statistik didapat hasil dari data T hitung = 8.91 > T tabel = 2.093 dengan taraf  = 0.05. Hasil penelitian ini menunjukkan terdapat pengaruh antara Latihan kekuatan otot lengan terhadap kemampuan Tembakan Hukuman (Free Throw) dalam bola basket pada club Basket Adhyaksa Kepahiang, sehingga dapat disimpulkan bahwa latihan kekuatan otot lengan mempengaruhi peningkatan bola yang masuk ke dalam ring basket pada tes (Free Throw) dan dapat dijadikan metode latihan untuk meningkatkan prestasi atlet

Mobile Systems Research with Drones

Robot vehicle platforms, often called “drones”, offer exciting new opportuni- ties for mobile computing. While many systems respond to device mobility (such as smartphones), drones allow computer systems to actively control device location, allowing them to interact with the physical world in new ways and with new-found scale, efficiency, or precision