Novel Haptic Cueing for UAV Tele-Operation.

The use of Unmanned Aerial Vehicles (UAVs) is continuously increasing both for military and civilian operations. The degree of automation inside an UAV has reached the capability of high levels of autonomy, increasing but human participation/action is still a requirement to ensure an ultimate level of safety for the mission. Direct remote piloting is often required for a board range of situations; this is true especially for larger UAVs, where a fault might be dangerous for the platform but even for the other entities of its environment (people, building etc.). Unfortunately the physical separation between pilot/operator and the UAV reduces greatly the situational awareness; this has a negative impact on system performance in the presence of remote and unforeseen environmental constraints and disturbances. This is why this thesis is dedicated to the study of means to increase the level of situational awareness of the UAV operator. The sense of telepresence is very important in teleoperation, and it appears reasonable, and it has already been shown in the literature, that extending the visual feedback with force feedback is able to complement the visual information (when missing or limited). An artificially recreated sense of touch (haptic) may allow the operator to better perceive information from the remote aircraft state, the environment and its constraints, hopefully preventing dangerous situations. This thesis introdues first a novel classification for haptic aid systems in two large classes: Direct Haptic Aid (DHA) and Indirect Haptic Aid (IHA), then, after showing that almost all existing aid concepts belong to the first class, focuses on IHA and tries to show that classical applications (that used a DHA approach) can be revised in a IHA fashion. The novel IHA systems produce different sensations, which in most cases may appear as exactly "opposite in sign" from the corresponding DHA; these sensations can provide valuable cues for the pilot, both in terms of improvement of performance and "level of appreciation". Furthermore, it will be shown that the novel cueing algorithms, which were designed just to appear "natural" to the operator, and not to directly help the pilot in his task (as in the DHA cases), can outperform the corresponding DHA systems. Three case studies were selected: obstacle avoidance, wind gust rejection, and a combination of the two. For all the cases, DHA and IHA systems were designed and compared against baseline performance with no haptic aid. Test results show that a net improvement in terms of performance is provided by employing the IHA cuse instead of both the DHA cues or the visual cues only. Both professional pilots and naïve subjects were used in some of the experiments. The perceived feelings transmitted by the haptic cues, strongly depend by the type of the experiment and the quality of the participants: the professional pilots, for instance, retained the DHA the most helpful force while they preferred IHA because they found it more natural and because they felt a better control authority on the aircraft; different results were obtained with naive participants. In the end, this thesis aim is to show that the IHA philosophy is a valid and promising alternative to the other commonly used, and published in the scientific literature, approaches which fall in the DHA category. Finally the haptic cueing for the obstacle avoidance task was tested in the presence of time delay in the communication link, as in a classical bilateral teleoperation scheme. The Master was provide with an admittance controller and an observer for force exerted by the human on the stick was developed. Experiments have shown that the proposed system is capable of standing substantial communication delays

Motion feedback in the teleoperation of Unmanned Aerial Vehicles

Teleoperation of unmanned vehicles is a valuable tool in scenarios where the operator can not or should not operate the vehicle from on-board. Applications range from hazardous environments where exposure needs to be avoided, control of Unmanned Aerial Vehicles (UAV) to retrieve overviews of inaccessible disaster areas, to deep sea exploration where on-board operation is simply not possible. However, limitations in sensor performance, noise and laten- cies introduced in the transmission, and ineffective display of the information to the operator can lead to a reduced amount of infor- mation, reduced performance, a loss of situation awareness, and in the worst case a loss of the remote vehicle. The spatial decoupling between the operator and the vehicle is one of the main challenges in teleoperation. Most setups include one or more control sticks to steer the ve- hicle, a monitor displaying the live video feed of the main vehicle camera, and a seat for the operator. This can be extended by display- ing additional state information using monitors or visual overlay, rendered on top of the main video stream [Tvaryanas, 2004; van Erp, 2000]. However, processing of multiple screens can increase mental workload. This can cause the operator to miss important information, leading to a loss of situation awareness and reduced performance or a crash of the vehicle. Instead of presenting information purely visually, other feedback modalities can be used to convey vehicle state or information about the task. The goal of this PhD thesis is to investigate the possibility of providing additional information using motion feedback. Here, motion feedback is defined as physically moving the operator using a motion simulator. In the work presented in this thesis a distinction between two motion feedback types is made. Vehicle-state motion feedback describes vehicle motion, while task-related motion feedback is the result of the combination of desired and actual vehicle motion. To investigate the effects of motion feedback in teleoperation several studies have been conducted. In the experiments presented participants either controlled a virtual quadrotor flying in a simu- lated environment or a real octorotor. Participants controlled the UAV from within the CyberMotion Simulator (CMS), an 8-DOF motion simulator located at the Max Planck Institute for Biological Cybernetics. The results show that providing motion feedback has a positive effect on performance in teleoperation of remote UAVs. If the remote vehicle is subject to external disturbances, e.g., wind gusts, vehicle- state feedback showed to improve disturbance rejection capabilities leading to increased performance. Furthermore, motion feedback can be shaped to include additional information about the task with positive effects on performance. This shows that the additional information included in the motion feedback can be used by the operator to improve performance and control behavior.Die Teleoperation eines unbemannten Gefährts ist ein wertvolles Werkzeug in Situationen, in denen der Pilot das Gefährt nicht von Bord aus steuern kann oder sollte. Beispiele hierfür reichen von, für den Piloten, toxischen Umgebungen, über Luftaufnahmen von Katastrophengebieten mithilfe von unbemannten Flugzeugen (engl. Unmanned Aerial Vehicle(UAV)), bis zur Erforschung der Tiefsee, bei der die Steuerung von Bord schlichtweg unmöglich wird. Allerdings führen Einschränkungen in der Sensorerfassung, Rau- schen und Latenzen in der Übertragung, sowie eine ineffiziente Darstellung der Informationen für den Piloten dann zu einem redu- zierten Informationsfluss, reduzierter Leistung, einem Verlust des Situationsbewusstseins und im schlimmsten Fall zu einem Verlust des Gefährts. Die räumliche Entkopplung zwischen dem Piloten und des Flugobjekts ist eine der wichtigsten Herausforderungen in der Teleoperation von UAVs. Die meisten Kontrollstationen beinhalten ein oder mehrere Steu- erknüppel um das Gefährt zu steuern, einen Monitor der eine di- rekte Videoübertragung der Hauptkamera anzeigt und ein Sitzplatz für den Piloten. Dies kann erweitert werden, in dem zusätzliche Statusinformationen mit weiteren Monitoren oder visuellen Über- lagerungen, die über die Hauptübertragung gezeichnet werden, angezeigt werden [Tvaryanas, 2004; van Erp, 2000]. Jedoch kann die Verarbeitung mehrerer Bildschirme die mentale Belastung erhö- hen. Dies kann dazu führen, dass der Pilot wichtige Informationen nicht aufnimmt, was zu einem Verlust des Situationsbewusstseins und einhergehender reduzierten Leistung oder einem Unfall des Gefährts führt. Anstatt Information rein visuell zu präsentieren, können ande- re Modalitäten genutzt werden Rückmeldungen über den Status des Gefährts oder Informationen über die Aufgabe zu präsentieren. Das Ziel dieser Doktorarbeit ist die Untersuchung der Modalität der Bewegung. Es soll untersucht werden, ob Bewegungen genutzt werden können, um dem Piloten zusätzliche Rückmeldungen über den Zustand des Gefährts bereit zu stellen. Bewegungsfeedback beschreibt hier die physikalische Bewegung des Piloten mit Hilfe eines Bewegungssimulators. In dieser Arbeit wird zwischen zwei Typen von Bewegungsfeedback unterschieden. Fahrzeugzustandsbe- wegungsfeedback beschreibt die Bewegung des Fahrzeugs, während Aufgabenabhängiges Bewegungsfeedback die Kombination aus tatsächli- chem und gewünschtem Fahrzeugzustand ist. Die Effekte von Bewegungsfeedback in der Teleoperation wurden in mehreren Studien untersucht. In den vorgestellten Experimenten kontrollierten Teilnehmer entweder einen virtuellen Quadrotor, der in einer simulierten Umgebung flog, oder einen echten Octorotor. Die Teilnehmer steuerten das UAV von der Kanzel des CyberMotion Simulators (CMS) aus, ein 8-DOF Bewegungssimulator, der sich am Max-Planck-Institut für biologische Kybernetik befindet. Die Ergebnisse zeigen, dass die Bereitstellung von Bewegungs- feedback positive Effekte auf die Leistung und das Verhalten des Piloten in der Steuerung des UAVs hat. Ist das UAV externen Stö- rungen ausgesetzt, wie z.B. Windstößen, zeigte sich, dass Fahr- zeugzustandsbewegungsfeedback die Fähigkeit der Störungsunter- drückung des Piloten verbessert, was zu Leistungsteigerungen führt. Außerdem zeigte sich, dass Bewegungsfeedback dahingehend ge- formt werden kann, zusätzliche Informationen über die Aufgabe bereitzustellen. Dies zeigt, dass die zusätzlichen Informationen vom Piloten genutzt werden können um Leistung und Kontrollverhalten zu verbessern

VFH+ based shared control for remotely operated mobile robots

This paper addresses the problem of safe and efficient navigation in remotely controlled robots operating in hazardous and unstructured environments; or conducting other remote robotic tasks. A shared control method is presented which blends the commands from a VFH+ obstacle avoidance navigation module with the teleoperation commands provided by an operator via a joypad. The presented approach offers several advantages such as flexibility allowing for a straightforward adaptation of the controller's behaviour and easy integration with variable autonomy systems; as well as the ability to cope with dynamic environments. The advantages of the presented controller are demonstrated by an experimental evaluation in a disaster response scenario. More specifically, presented evidence show a clear performance increase in terms of safety and task completion time compared to a pure teleoperation approach, as well as an ability to cope with previously unobserved obstacles.Comment: 8 pages,6 figure

Effects of haptic feedback in dual-task teleoperation of a mobile robot

Teleoperation system usage is challenging to human operators, as this system has a predominantly visual interface that limits the ability to acquire situation awareness, (e.g. maintain a safe teleoperation). This limitation coupled with the dual-task problem of teleoperating a mobile robot, negatively affects the operators cognitive load and motor skills. Our motivation is to offload some of the visual information to a secondary perceptual channel (haptic), by proposing an assisted teleoperation system. This system uses haptic feedback to alert the operator of obstacle proximity, without directly influencing the operator’s command inputs. The objective of this paper, is to evaluate and validate the efficacy of our system’s haptic feedback, by providing the obstacle proximity information to the operator. The user experiment was conducted to emulate the dual-task problem, by having a concurrent task for cognitive distraction. Our results showed significant differences in time to complete the navigation task and the duration of collisions, between the haptic feedback condition and the control condition.info:eu-repo/semantics/acceptedVersio

The classification and new trends of shared control strategies in telerobotic systems: A survey

Shared control, which permits a human operator and an autonomous controller to share the control of a telerobotic system, can reduce the operator's workload and/or improve performances during the execution of tasks. Due to the great benefits of combining the human intelligence with the higher power/precision abilities of robots, the shared control architecture occupies a wide spectrum among telerobotic systems. Although various shared control strategies have been proposed, a systematic overview to tease out the relation among different strategies is still absent. This survey, therefore, aims to provide a big picture for existing shared control strategies. To achieve this, we propose a categorization method and classify the shared control strategies into 3 categories: Semi-Autonomous control (SAC), State-Guidance Shared Control (SGSC), and State-Fusion Shared Control (SFSC), according to the different sharing ways between human operators and autonomous controllers. The typical scenarios in using each category are listed and the advantages/disadvantages and open issues of each category are discussed. Then, based on the overview of the existing strategies, new trends in shared control strategies, including the “autonomy from learning” and the “autonomy-levels adaptation,” are summarized and discussed

Attitude perception of an unmanned ground vehicle using an attitude haptic feedback device

In order to safely teleoperate an unmanned ground vehicle (UGV) through rough terrain, a human operator needs to be aware of its attitude. This awareness ensures (s)he can avoid rolling or tipping over the UGV, due to steep slopes or terrain depressions. Yet, it has been challenging to develop teleoperation systems that can provide attitude awareness, to human operators. So far, all research has been focused in implementing solutions through visual modality. We take a different approach, using haptic feedback to transmit an UGV's attitude to an human operator. Our novel attitude haptic feedback device (AHFD) provides information about the UGV's roll and pitch, and their direction of rotation, thorugh the use of upper limb proprioception. We also discuss a preliminary user study to understand the influence two different AHFD configurations (natural and ergonomic) have on attitude perception. Our results indicate there is no difference between the two AHFD configuration in judging attitude states and direction of rotations. Yet, natural configuration is perceived as causing higher physical strain and demand, while the ergonomic a higher overall mental effort. We also found participants had more difficulty in judging pitch attitude at higher angles.info:eu-repo/semantics/acceptedVersio

Evaluation of haptic guidance virtual fixtures and 3D visualization methods in telemanipulation—a user study

© 2019, The Author(s). This work presents a user-study evaluation of various visual and haptic feedback modes on a real telemanipulation platform. Of particular interest is the potential for haptic guidance virtual fixtures and 3D-mapping techniques to enhance efficiency and awareness in a simple teleoperated valve turn task. An RGB-Depth camera is used to gather real-time color and geometric data of the remote scene, and the operator is presented with either a monocular color video stream, a 3D-mapping voxel representation of the remote scene, or the ability to place a haptic guidance virtual fixture to help complete the telemanipulation task. The efficacy of the feedback modes is then explored experimentally through a user study, and the different modes are compared on the basis of objective and subjective metrics. Despite the simplistic task and numerous evaluation metrics, results show that the haptic virtual fixture resulted in significantly better collision avoidance compared to 3D visualization alone. Anticipated performance enhancements were also observed moving from 2D to 3D visualization. Remaining comparisons lead to exploratory inferences that inform future direction for focused and statistically significant studies

GoonDAE: Denoising-Based Driver Assistance for Off-Road Teleoperation

Because of the limitations of autonomous driving technologies, teleoperation is widely used in dangerous environments such as military operations. However, the teleoperated driving performance depends considerably on the driver's skill level. Moreover, unskilled drivers need extensive training time for teleoperations in unusual and harsh environments. To address this problem, we propose a novel denoising-based driver assistance method, namely GoonDAE, for real-time teleoperated off-road driving. The unskilled driver control input is assumed to be the same as the skilled driver control input but with noise. We designed a skip-connected long short-term memory (LSTM)-based denoising autoencoder (DAE) model to assist the unskilled driver control input by denoising. The proposed GoonDAE was trained with skilled driver control input and sensor data collected from our simulated off-road driving environment. To evaluate GoonDAE, we conducted an experiment with unskilled drivers in the simulated environment. The results revealed that the proposed system considerably enhanced driving performance in terms of driving stability.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl