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The future role of relay satellites for orbital telerobotics
Abstract
Orbital robotics focuses on a variety of applications, as e.g. inspection and repair activities, spacecraft construction or orbit correc-tions. On-Orbit Servicing (OOS) activities have to be closely monitored by operators on ground. A direct contact to the spacecraft in Low Earth Orbit (LEO) is limiting the operational time of the robotic application. Therefore, geostationary satellites are desirable to relay the OOS signals and extend the servicing time window. A geostationary satellite in the communication chain not only introduces additional boundary conditions to the mission but also increases the time delay in the system. The latter is not very critical if the servicer satellite is operating autonomously. However, if the servicer is operating in a supervised control regime with a human in the loop, the increased time delay will have an impact on the operator's task performance. This paper describes the challenges, which have to be met when utilizing a relay satellite for orbital telerobotics. It shows a series of ground experiments that were undertaken with a relay satellite in the communication chain to simulate the end-to-end system. This case study proves that complex robotic applications in Low Earth Orbit (LEO) are controllable by human operators on ground.
... The most important key aspects to control a drone safely and to successfully accomplish a teleoperated search and rescue applications are: C Round trip delays (time to transmit a packet from the operator to the drone and back to the operator) C Time delay variation (the variability of the delay, not necessarily the delay variance, is commonly termed time delay variation [6]) C Streaming measurements (mean data throughput to the drone). Efficiency of executing a teleoperated task depending on the latency time [8]. ...
... Knowledge of the network jitter in teleoperated systems is important because jitter results in packet ar-rival at the receiver queue in permuted order. An increasing delay may result in empty sampling instances at the receiver side, reducing the immersion of the teleoperator significantly [6]. ...
... Higher values (> 90 ms) require so called dejittering actions to ensure a good immersion. This means the packets are buffered and reordered according to their sequence number and time stamp [6]. ...
... The system model under consideration in this study is composed of a teleoperated robot on a planetary surface and an operator located on orbiting space vehicle or in a terrestrial location connected via a secure communication channel that can facilitate relay satellites in between. However, relay satellites increase the time delay in the system; thus, carefully selecting encryption methods is vital for the system's efficacy [16]. The mission scenario is to use construction blocks to construct a habitat model on the surface of a planet. ...
... A tethered satellite system (TSS) is a system consisting of few spacecrafts connected by a tether, which is in a form of a very thin cable made of different materials depending on its suitability to the space the T years, Throughout mission requirements. a of mode as been has SS utilised transportation, propulsion system, tidal stabilisation and many others [2,5,6]. Most of the previous work done on TSS are focused more on just a rigid model due to the non-complex nature of the system dynamics [1]. ...
This paper presents a numerical model for a flexible tethered satellite system in both planar and co-planar environment. This tethered satellite system consists of three rigid bodies with two flexible tethers, each connecting two rigid bodies with one located in the center serving as the mothership. The dynamics of the system include tether deformations, rotational dynamics and orbital mechanics. Five different materials that are commonly used will be tested accordingly in order to observe its performance based on the tension of the tether. It is found that, based on all of the materials simulated, diamond has the best tension performance.
In a space telerobot system (STS), effectiveness of the control method in eliminating the time delay's influences is advisable to be verified under the real circumstance. However, it is difficult and costly for many scholars to obtain confidential information that would allow them to establish an STS. It may be feasible, using some existing results, to model the time delay as close to reality as possible, and to then program a simulation system to generate the simulated time delay, thus verifying validity. In this article, time-delay modeling and simulation problems for relay communication-based STS are first studied. The time delay in relay communication-based STS consists of both processing and communication time delays; the latter is divided into ground and ground-space parts. By extending the available results, processing and ground communication time delays are modeled with the probability distribution function modeling approach. An optimal communication link identification and minimum time-delay realization (OCLIMTDR) method is proposed to model the ground-space communication time delay. In this method, the novel point-vector-sphere (PVS) algorithm serves to judge link connectivity. The PVS algorithm is based on geometric theory, which gives the OCLIMTDR method good extensibility and renders it suitable for any relay communication network in theory. All three parts of the time-delay models are integrated to form the loop time-delay model of the STS. Subsequently, a time-delay simulation system is created by programming the loop time-delay model. Finally, the correctness of the simulation system is further authenticated based on simulations and some prior knowledge.
In data relay satellite (DRS) systems, users compete for limited inter-satellite link antenna beam (ILAB) resources of data relay satellites by submitting excessive service requests to the mission scheduling center (MSC), which leads to serious scheduling conflicts and considerably degrades the QoS (quality of service). Two key challenges, the effective mission scheduling and the coordination of multiple users' behaviors in submitting service requests, are involved in this issue. Most of the previous works have only focused on the mission scheduling issue, while neglecting the impact of users' selfish behavior on the QoS. In this paper, we investigate the resource allocation problem in DRS systems from the perspective of users' behavior analysis, i.e., joint coordination of users' selfish behavior in submitting service requests and mission scheduling. Since those selfish users have no incentive to cooperate in the one-shot interaction, we construct a repeated game framework with a proper punishment and forgiveness strategy to maximize users' payoffs and meanwhile to reduce the resource conflicts through a cooperative way. Moreover, an efficient cheat-proof mechanism is proposed to make users self-enforced to submit his/her actual resource requirement. Simulation results confirm that the proposed scheme can significantly improve the system operational performance. Compared with the payoffs under the Nash equilibrium in the one-shot game which is the main method of the current coordination scheme for DRS systems, our proposed joint method based on the repeated game framework can acquire 1.36 to 3.46 times gain in respect to 2 to 10 users, and also effectively decrease the resource conflicts.
On-orbit servicing (OOS) is a part of an emerging category of future on-orbit activities which are critical for taking the next leap in the use of earth orbit, especially in geostationary orbit (GEO). The ability to repair or refuel satellites, construct new satellites in orbit, and even assemble large space facilities can help drive innovative uses of space. Combined with the rapid development of the micro-satellite technology, a novel micro-satellite swarm robot servicing system (MSRSS) is designed, which consists of one communication robot, two servicing robots (two robot arms), and two monitor robots. All the robots in the system are designed based on micro-satellite platform, and collaborated to execute monitoring/measuring, capture, maintenance, repair and other tasks, at the same time, some module satellite can be used as part of a satellite to replace the existing module. This new program can solve the disadvantage of a single large robot satellite, and micro-satellite based platform can reduce costs and improve the fast response. The use of micro-satellite in OOS includes two aspects: (1) the formation of micro-swarm robots in OOS instead of a single large space robot platform; (2) as part of the servicing object (such as U.S. Phoenix).
Large satellites and exquisite planetary missions are generally self-contained. They have, onboard, all of the
computational, communications and other capabilities required to perform their designated functions. Because of this,
the satellite or spacecraft carries hardware that may be utilized only a fraction of the time; however, the full cost of
development and launch are still bone by the program. Small satellites do not have this luxury. Due to mass and volume
constraints, they cannot afford to carry numerous pieces of barely utilized equipment or large antennas.
This paper proposes a cloud-computing model for exposing satellite services in an orbital environment. Under this
approach, each satellite with available capabilities broadcasts a service description for each service that it can provide
(e.g., general computing capacity, DSP capabilities, specialized sensing capabilities, transmission capabilities, etc.) and
its orbital elements. Consumer spacecraft retain a cache of service providers and select one utilizing decision making
heuristics (e.g., suitability of performance, opportunity to transmit instructions and receive results – based on the orbits
of the two craft). The two craft negotiate service provisioning (e.g., when the service can be available and for how long)
based on the operating rules prioritizing use of (and allowing access to) the service on the service provider craft, based
on the credentials of the consumer.
Service description, negotiation and sample service performance protocols are presented. The required components of
each consumer or provider spacecraft are reviewed. These include fully autonomous control capabilities (for provider
craft), a lightweight orbit determination routine (to determine when consumer and provider craft can see each other and,
possibly, pointing requirements for craft with directional antennas) and an authentication and resource utilization
priority-based access decision making subsystem (for provider craft).
Two prospective uses for the proposed system are presented: Earth-orbiting applications and planetary science
applications. A mission scenario is presented for both uses to illustrate system functionality and operation. The
performance of the proposed system is compared to traditional self-contained spacecraft performance, both in terms of
task performance (e.g., how well / quickly / etc. was a given task performed) and task performance as a function of cost.
The integration of the proposed service provider model is compared to other control architectures for satellites including
traditional scripted control, top-down multi-tier autonomy and bottom-up multi-tier autonomy.
Recently, as a satellite mission becomes complicated, it has been required to generate the schedule of satellite antenna movements automatically without relying upon operator’s ad hoc knowledge. To generate the satellite antenna schedule autonomously, this paper first addresses geometrical problems associated with the antenna scheduling and mission planning problems that can be formulated from satellite navigation and antenna orientation information. Then, based on the solutions of the geometrical problems, a set of antenna azimuth and elevation angles that enables the antenna to point towards the desired ground station is obtained systematically. Using the computed azimuth and elevation angles, the satellite tracking profile (TP) is generated, and to validate it, TP validation algorithms are developed.
Upcoming space missions in the fields of on-orbit servicing and space debris removal will face highly complex tasks which require significant increases in complexity and capability of spacecraft systems, as well as increased dexterity of manipulators. In order to provide methods and technologies allowing real-time teleoperation in orbit, the Institute of Astronautics (LRT) at the Technical University Munich (TUM) is researching different technologies that will be needed for this new type of spacecraft mission operations. With the on-orbit servicing scenario as leading example mission, the main focus lies in developing technologies needed for teleoperated close-range proximity operations including inspection and docking maneuvers.
To properly estimate orbital lifetimes and predict the maneuverability of spacecraft, the remaining liquid propellant mass must be accurately known at every moment of a space mission. This paper studies the Compression Mass Gauge (CMG) method to determine the mass of liquid contained in a tank in a low-gravity environment with high accuracy. CMG is a thermodynamic method used to determine the quantity of liquid by measuring the gas pressure change when the tank volume changes, and has been previously theoretically and experimentally studied by researchers. The primary objective of this investigation is to explore the effects of attitude disturbance and the spacecraft thermal environment on the accuracy of the method. A ground test system, consisting of several test apparatuses, was fabricated and described as part of this study. The test results and analyses indicate that the CMG performs well and has an accuracy of ±1%. Additionally, demonstrations were performed to show that measurement errors do not increase drastically or exceed ±1% when the test system is vibrated to simulate the tank being perturbed as a result of an attitude disturbance. Liquid sloshing resonance was found to have a significant effect on the gauging accuracy. Measurements in a real thermal environment in which heat transfers into and out of the propellant tank were also conducted. The results show that the gauging accuracy is acceptable for normal liquid propellant. Furthermore, theoretical research shows that heat leakage has a significant influence on cryogenic propellant mass gauging.
In this chapter we present an overview of the field of telerobotics with afocus on control aspects. Motivated by an historical
prespective and some challenging applications of this research area aclassification of control architectures is given, including
an introduction to the different strategies. An emphasis is taken on bilateral control and force feedback, which is avital
research field today. Finally we suggest some literature for acloser engagement with the topic of telerobotics.
Human judgment is an integral part of the teleoperation process that is often heavily influenced by a single video feed returned from the remote environment. This limitation on the perceptual links to the environment leaves the operator prone to cognitive mistakes and general disorientation. These faults may be enhanced or muted, depending on the camera mountings and control opportunities that are at the disposal of the operator. These issues form the basis for an experiment to assess the effectiveness of existing and potential teleoperation controls. Findings suggest that providing a camera that is controlled independently from the orientation of the vehicle may yield significant benefits.
The Haptik Library is component based architecture for uniform access to haptic devices. It introduces many advantages besides device independency, such as driver version transparency and both backward and future binary compatibility with new devices, drivers and APIs, thus solving many problems that arise when using other libraries or native SDKs. One of the key features of the Haptik Library is its plugin-based architecture that allows the addition of support for latest devices and drivers without requiring recompilation of the library or existing client applications. Moreover, the library has been designed to be easily used in existing complex applications with different architectures and even when replacing previously used libraries tor haptic device access. Its use is therefore recommended to add haptic rendering into already existing applications, to develop research applications requiring custom graphic engines, and to achieve easy but powerful low-level access to haptic devices.
A patent-pending, energy-based method is presented for controlling
a haptic interface system to ensure stable contact under a wide variety
of operating conditions. System stability is analyzed in terms of the
time-domain definition of passivity. We define a "passivity observer"
(PO) which measures energy flow in and out of one or more subsystems in
real-time software. Active behavior is indicated by a negative value of
the PO at any time. We also define the "passivity controller" (PC), an
adaptive dissipative element which, at each time sample, absorbs exactly
the net energy output (if any) measured by the PO. The method is tested
with simulation and implementation in the Excalibur haptic interface
system. Totally stable operation was achieved under conditions such as
stiffness >100 N/mm or time delays of 15 ms. The PO/PC method
requires very little additional computation and does not require a
dynamical model to be identified
A 30-year history of research on dealing with the effects of time
delay in the control loop on human teleoperation in space is reviewed.
Experiments on the effects of delay on human performance are discussed,
along with demonstrations of predictive displays to help the human
overcome the delay. Supervisory control is shown to offer a variety of
options, from switching to local impedance control upon contact with the
environment to higher-level local automation. Wave transformation
techniques to ameliorate the effects of delay are also described. Space
teleoperations have tended to deal with the problem of time delay by
avoiding it and not attempting to teleoperate from the ground. It is
suggested that the US space effort might have gotten further ahead and
at a lower cost with a greater is commitment to space teleoperation from
the ground through the delay. Predictive display works well for free
positioning. Local impedance control is recommended for control in
contact with the environment, possibly accompanied by wave
transformation techniques. Higher level supervisory control is always an
option for sufficiently predictable tasks and will continue to improve
with better sensors and task models
The article addresses the technical principles of a new high-performance haptic device, called HapticMaster, and gives an overview of its haptic performance. The HapticMaster utilizes the admittance control paradigm, which facilitates high stiffness, large forces, and a high force sensitivity. On top of that the HapticMaster has a large workspace, and a huge haptic resolution. Typical applications for the HapticMaster are therefore found in virtual reality, haptics research, and rehabilitation.
The capability to routinely perform autonomous docking is a key enabling technology for future space exploration, as well as assembly and servicing missions for spacecraft and commercial satellites. Particularly, in more challenging situations where the target spacecraft or satellite is tumbling, algorithms and strategies must be implemented to ensure the safety of both docking entities in the event of anomalies. However, difficulties encountered in past docking missions conducted with expensive satellites on orbit have indicated a lack of maturity in the technologies required for such operations. Therefore, more experimentation must be performed to improve the current autonomous docking capabilities. The main objectives of the research presented in this thesis are to develop a guidance, navigation and control (GN&C) architecture that enables the safe and fuel-efficient docking with a free tumbling target in the presence of obstacles and anomalies, and to develop the software tools and verification processes necessary in order to successfully demonstrate the GN&C architecture in a relevant environment. The GN&C architecture was developed by integrating a spectrum of GN&C algorithms including estimation, control, path planning, and failure detection, isolation and recovery algorithms.
Large spacecraft and satellites can suffer costly on-orbit failures. In many cases, it would be helpful to have a small inspection satellite that can detach from and visually inspect the larger host spacecraft. This type of small inspection satellite must be carefully designed to minimize both the requirements imposed on the host and the risk of collision. For this reason a relative navigation system must be highly reliable and accurate. This paper discusses the design, implementation and testing of a navigation system that utilizes single-camera computer vision based navigation to estimate the 12 Degree of Freedom relative state. This system uses a fiducial target that is designed to be as small as possible, in order to reduce the space requirement on the host spacecraft. The difficulties of using only the minimum point features are discussed and a nonlinear estimation approach is presented that can overcome these issues. These algorithms are implemented and experimentally tested on the SPHERES satellites, and an upper bound on the precision and accuracy is reported.
The deployment of space robots for servicing and maintenance operations that are teleoperated from the ground is a valuable addition to existing autonomous systems, because it will provide flexibility and robustness in mission operations. In this connection, not only robotic manipulators are of great use, but also free-flying inspector satellites supporting the operations through additional feedback to the ground operator. The manual control of such an inspector satellite at a remote location is challenging, because navigation in three-dimensional space is unfamiliar and large time delays can occur in the communication channel. This paper shows a series of robotic experiments, in which free flyers are controlled by astronauts aboard the International Space Station (ISS). The Synchronized Position Hold Engage Reorient Experimental Satellites (SPHERES) were utilized to study several aspects of a remotely controlled inspector satellite. The focus in this case study is investigating different approaches to human–spacecraft interaction with varying levels of autonomy under zero-gravity conditions. © 2012 Wiley Periodicals, Inc. © 2012 Wiley Periodicals, Inc. (This work was done while Dr. Stoll was a Postdoctoral Fellow at the MIT Space Systems Laboratory. His current affiliation is RapidEye AG, Brandenburg, Germany.)
Since the 1960s, NASA has performed numerous rendezvous and docking missions. The common element of all US rendezvous and docking is that the spacecraft has always been piloted by astronauts. Only the Russian Space Program has developed and demonstrated an autonomous capability. The Demonstration of Autonomous Rendezvous Technology (DART) project currently funded under NASA's SPace Launch Initiative (SLI) Cycle I , provides a key step in establishing an autonomous rendezvous capaibility for the United States. The Objective of the DART mission is to demonstrate, in space, the hardware and software necessary for autonomous rendezvous. Orbital Sciences Corporation intends to integrate an Advanced Video Guidance Sensor and Autonomous Rendezvous and Proximity Operations algorithms into a Pegasus upper stage in order to demonstrate the capability to autonomously rendezvous with a target currently in orbit. The DART mission will occur in April 2004. The launch site will be Vandenberg AFB and the launch vehicle will be a Pegasus XL equipped with a Hydrazine Auxiliary Propulsion System 4th Stage. All mission objectives will be completed within a 24 hour period. The paper provides a summary of mission objectives, mission overview and a discussion on the design features of the chase and target vehicles.
Air Force Research Laboratory"s space experiment XSS-10 was flown on the Air Force Global Positioning Satellite (GPS) mission IIR-8 launched on January 29, 2003. The mission objectives of XSS-10 were to demonstrate autonomous navigation, proximity operations, and inspection of a Resident Space Object (RSO). XSS-10 was a 28-kilogram micro-satellite was launched as a secondary mission on a Delta II expendable launch vehicle carrying a GPS satellite. XSS-10 was equipped with a visible camera, a star sensor, and mini SGLS system, all specially built for this program. In addition, a visible camera was attached to the second stage to observe the release of the micro-satellite and observe its maneuvers. Following the release of the GPS satellite, the Delta II initiated three depletion burns to reorient into an 800 KM circular orbit. The XSS-II was ejected from the Delta II second stage approximately 18 hours after launch. Operating autonomously on a preplanned course, XSS-10 performed its mission of navigating around the Delta II second stage at preplanned positions; the micro-satellite took images of the second stage and send them back to earth in real time. During these demonstrations the XSS-10 mission operations team accomplished responsive checkout of the micro-satellite and all of its subsystems, autonomous navigation on a preplanned course and a variety of algorithms and mission operations that pave the way for more ambitious missions in the future. This paper will discuss the results of the mission and post mission analysis of the XSS-10 space flight.
Most malfunctioning spacecraft require only a minor maintenance operation, but have to be retired due to the lack of so-called
On-Orbit Servicing (OOS) opportunities. There is no maintenance and repair infrastructure for space systems. Occasionally,
space shuttle based servicing missions are launched, but there are no routine procedures foreseen for the individual spacecraft.
The unmanned approach is to utilize the explorative possibilities of robots to dock a servicer spacecraft onto a malfunctioning
target spacecraft and execute complex OOS operations, controlled from ground. Most OOS demonstration missions aim at equipping
the servicing spacecraft with a high degree of autonomy. However, not all spacecraft can be serviced autonomously. Equipping
the human operator on ground with the possibility of instantaneous interaction with the servicer satellite is a very beneficial
capability that complements autonomous operations. This work focuses on such teleoperated space systems with a strong emphasis
on multimodal feedback, i.e. human spacecraft interaction is considered, which utilizes multiple human senses through which
the operator can receive output from a technical device. This work proposes a new concept for free flyer control and shows
the development of an according test environment.
Haptik is a component based library recently developed at the University of Siena. It allows easy but powerful low-level access to haptic devices, both in a uniform way, common to all devices, or in a more specialized one. Haptik addresses haptic device access. It is non-invasive and easily usable with existing applications. Its architecture guarantees a binary compatibility of applications with future versions of devices, library and plugins, still maintaining the maximum performance achiev- able directly with devices SDKs. The library is freely downloadable at http://sirslab.dii.unisi.it/haptic/haptik.htm
Remote control of underwater vehicles and other robotic systems has, up
until now, proved to be a challenging task for the human operator. With
technology advancements in computers and displays, computer interfaces
can be used to alleviate the workload on the operator. This research
introduces the concept of a commanded display, which is a graphical
simulation that shows the commands sent to the actual system in
real-time. The primary goal of this research was to show a commanded
display as an alternative to the traditional predictive display for
reducing the effects of time delay. Several experiments were used to
investigate how subjects compensated for time delay under a variety of
conditions while controlling a 7-degree of freedom robotic manipulator.
Results indicate that time delay increased completion time linearly;
this linear relationship occurred even at different manipulator speeds,
varying levels of error, and when using a commanded display. The
commanded display alleviated the majority of time delay effects, up to
91% reduction. The commanded display also facilitated more accurate
control, reducing the number of inadvertent impacts to the task
worksite, even when compared to no time delay. Even with a moderate
error between the commanded and actual displays, the commanded display
was still a useful tool for mitigating time delay. The way subjects
controlled the manipulator with the input device was tracked and their
control strategies were extracted. A correlation between the subjects'
use of the input device and their task completion time was determined.
The importance of stereo vision and head tracking was examined and shown
to improve a subject's depth perception within a virtual environment.
Reports of simulator sickness induced by display equipment, including a
head mounted display and LCD shutter glasses, were compared. The results
of the above testing were used to develop an effective virtual
environment control station to control a multi-arm robot.
An Inter-Satellite Link Antenna (LISA), developed for transmitting data via a geostationary relay satellites is attached to a three degree of freedom satellite attitude simulator in order to validate not only the pointing mechanism of the antenna but also the algorithms on-ground. While the device is simulating a satellite orbiting in LEO the antenna will compensate the rotational motions and maintain a link to the ESA relay satellite ARTEMIS. This paper gives an overview on the efforts that have be undertaken to use real satellite data for testing the link maintenance of the inter satellite link antenna on-ground. For reproducing satellite attitude by means of a simulator with 3 rotational degrees of freedom an inter-satellite link based coordinate frame is not only introduced at the orbiting satellite and but also at the satellite on the simulator on-ground. This coordinate frame and related Euler angle conversions are the basis for obtaining angular data which is essential for the actuators of the simulator.
In force-reflecting telepresence, communication delays can lead to instability. A common approach to passivate the system disturbed by constant delays is to apply the wave transformation. However, this leads to the effect of wave reflections that decrease performance. This paper provides a detailed description of wave reflections as arising in haptic telepresence systems. The influence on the perception of the remote environment is analyzed and validated experimentally.
In an ideal case telepresence achieves a state in which a human operator can no longer differentiate between an interaction with a real environment and a technical mediated one. This state is called transparent telepresence. The applicability of telepresence to on-orbit servicing (OOS), i.e., an unmanned servicing operation in space, teleoperated from ground in real time, is verified in this paper. For this purpose, a communication test environment was set up on the ground, which involved the Institute of Astronautics (LRT) ground station in Garching, Germany, and the European Space Agency (ESA) ground station in Redu, Belgium. Both were connected via the geostationary ESA data relay satellite ARTEMIS. Utilizing the data relay satellite, a teleoperation was accomplished in which the human operator as well as the (space) teleoperator was located on the ground. The feasibility of telepresent OOS was evaluated, using an OOS test bed at the Institute of Mechatronics and Robotics at the German Aerospace Center (DLR). The manipulation task was representative for OOS and supported real-time feedback from the haptic-visual workspace. The tests showed that complex manipulation tasks can be fulfilled by utilizing geostationary data relay satellites. For verifying the feasibility of telepresent OOS, different evaluation methods were used. The properties of the space link were measured and related to subjective perceptions of participants, who had to fulfill manipulation tasks. An evaluation of the transparency of the system, including the data relay satellite, was accomplished as well. © 2009 Wiley Periodicals, Inc.
The time domain passivity framework is attracting
interest as a method for granting stability in both telerobotics
and haptic contexts; this paper employs this approach in order
to introduce a novel concept, the Bilateral Energy Transfer
for haptic telepresence. Loosely speaking, the Bilateral Energy
Transfer is the straightforward transfer of energy between
the two opposite sides of a teleoperation network, the master
and slave robots. In an ideal telepresence scenario master
and slave robots behave as rigid connected masses [1], and
their power exchange is lossless; conversely, realistic scenarios
include sources of energy leaks, i.e. elements that modify the
power flows in the network. Moreover, if energy leaks have an
active nature, they become source of instability for the system.
This work isolates two sources of instability normally present
in a teleoperation system, i.e. the delayed communication
channel and robot velocity estimation based on digital position
acquisition. These energy leaks are counterbalanced by two
independent controllers, whose design is based on energetic
consideration, and whose employment allows to achieve the Bilateral
Energy Transfer. The presented arguments are sustained
by simulations and experiments.
The paper outlines the long-term space robotics projects as well as recent results in DLR's robotics laboratory. The driving force behind all the efforts made in hardware and software development is to design highly integrated robot systems which can be utilized in space, especially for extravehicular activities. Our envisaged field of application reaches from servicing satellites in low Earth and geostationary orbit to space stations as well as planetary exploration robots, all of them fully ground controlled from Earth. The ground control concept is based on the MARCO architecture, which was verified in a few space robotics projects over recent years. It includes taskoriented programming capabilities for autonomous robot control at the remote site as well as methods for direct telemanipulation by means of virtual reality and telepresence techniques, which allows a realistic feeling for the ground operator via visual and haptic feedback devices. In addition to the control techniques, a new generation of ultra-lightweight robot arms with articulated hands is required to give the space robot systems the necessary dexterity. A number of experiments will verify and consolidate the usage of space robots. First, the ROKVISS experiment aims at the verification of DLR's lightweight robotics components under realistic mission conditions. Second, the TECSAS experiment will show the feasibility of autonomous as well as telepresence methods for further satellite servicing tasks. Third, a strong cooperation with industry will create the first business case in on-orbit-servicing: by attaching a tugboat to a satellite, whose propellant is declining, the lifetime of valuable telecommunication satellites could be prolonged for several years.
In this paper, a teleoperating system for minimal invasive surgery is discussed. The focus lies on different control laws for the force feedback loop in telesurgery scenarios and the comparison of them. Suitable control schemes for position and force controlled minimal invasive medical robots combined with a force feedback input device without necessarily sensing the operators forces are presented. The control is extended with control parameter adaption in the force feedback control law with the estimation of the environment stiffness.
Upcoming space missions utilizing hyperspectral or other high-resolution sensors will generate a vast amount of data in orbit. The average communication duration between a spacecraft in low Earth orbit (LEO) to a dedicated ground station is short and in addition, due to the high amount of data to be transferred at link times, a high-performance communication system on board of the satellite is indispensable.A solution that provides longer acquisition times with the ground station is to employ a high data-rate inter-satellite link to a geostationary relay satellite, which requires a flat, compact, steerable, light-weight yet robust antenna. Such an antenna system (antenna module plus pointing module) was developed for S-Band at the Institute of Astronautics (Technische Universität München), in cooperation with German space companies, research institutes and the German Aerospace Center (DLR). Its successful operation via the geostationary relay satellite Artemis was demonstrated in cooperation with ESA in 2007.This paper describes the evaluation of an antenna system in the Ka-Band, as a successor to be developed in the next two years for high data rates and the various applications of such an antenna system.
The use of telerobots in remote locations allows humans to extend
their capabilities to distant and hazardous environments. Although safer
for the operator, this extension of capabilities comes at a price. Due
to communication across great distances, experiencing time delays of up
to several seconds is common. Any time delay in the human/robot
interaction can significantly degrade the effectiveness of operator
control. This paper will looks at two common instances of
human-in-the-loop command of robots: command of vehicle motion and
command of a manipulator to perform an assembly task. Results from three
studies are summarized to show the degradation in performance caused by
varying levels of time delay
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2007. Includes bibliographical references (p. 307-324). The capability to routinely perform autonomous docking is a key enabling technology for future space exploration, as well as assembly and servicing missions for spacecraft and commercial satellites. Particularly, in more challenging situations where the target spacecraft or satellite is tumbling, algorithms and strategies must be implemented to ensure the safety of both docking entities in the event of anomalies. However, difficulties encountered in past docking missions conducted with expensive satellites on orbit have indicated a lack of maturity in the technologies required for such operations. Therefore, more experimentation must be performed to improve the current autonomous docking capabilities. The main objectives of the research presented in this thesis are to develop a guidance, navigation and control (GN&C) architecture that enables the safe and fuel-efficient docking with a free tumbling target in the presence of obstacles and anomalies, and to develop the software tools and verification processes necessary in order to successfully demonstrate the GN&C architecture in a relevant environment. The GN&C architecture was developed by integrating a spectrum of GN&C algorithms including estimation, control, path planning, and failure detection, isolation and recovery algorithms. (cont.) The algorithms were implemented in GN&C software modules for real-time experimentation using the Synchronized Position Hold Engage and Reorient Experimental Satellite (SPHERES) facility that was created by the MIT Space Systems Laboratory. Operated inside the International Space Station (ISS), SPHERES allow the incremental maturation of formation flight and autonomous docking algorithms in a risk-tolerant, microgravity environment. Multiple autonomous docking operations have been performed in the ISS to validate the GN&C architecture. These experiments led to the first autonomous docking with a tumbling target ever achieved in microgravity. Furthermore, the author also demonstrated successful docking in spite of the presence of measurement errors that were detected and rejected by an online fault detection algorithm. The results of these experiments will be discussed in this thesis. Finally, based on experiments in a laboratory environment, the author establishes two processes for the verification of GN&C software prior to on-orbit testing on the SPHERES testbed. by Simon Nolet. Sc.D.
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1996. Includes bibliographical references (p. 195-198). by Günter Niemeyer. Ph.D.
The effect on the performance of both simple and complex tasks of inserting transmission delay between the master and slave elements of a remote manipulator was studied. Most operators spontaneously adopted an effective “move-and-wait” strategy to cope with delay. A modification of a method proposed earlier enabled task-completion time to be accurately predicted from data taken when there was no delay. With the move-and-wait strategy, completion time depends on the length of sequences of open-loop movements. The number of such moves for positioning in one dimension as a function of task difficulty was found to agree with that predicted by a simple statistical model.
The National Space Development Agency of Japan (NASDA) launched
the ETS-VII (Engineering Test Satellite No.7) on November 28, 1997 to
conduct rendezvous docking and space robot technology experiments.
ETS-VII is the world's first satellite that used a robot arm on a
satellite. The robot arm was 2 m long and was tele-operated from the
on-ground control station. The mission of ETS-VII lasted for two years
and brought may experiences and results. The paper summarizes
experiences and results of the ETS-VII robot satellite
A control law for teleoperators is presented which overcomes the instability caused by time delay. By using passivity and scattering theory, a criterion is developed which shows why existing bilateral control systems are unstable for certain environments, and why the proposed bilateral control law is stable for any environment and any time delay. The control law has been implemented on a single-axis force-reflecting hand controller, and preliminary results are shown. To keep the presentation clear, a single-degree-of-freedom (DOF) linear time-invariant (LTI) teleoperator system is discussed. Nevertheless, results can be extended, without loss of generality, to an n-DOF nonlinear teleoperation system
Xss-10 micro-satellite flight demonstration, in: Proceedings of Georgia Institute of Technology Space Systems Engineering Confer-ence, paper no. GT-SSEC.D.3 The haptik library: a component based architecture for uniform access to haptic devices
- T Davis
- M De Pascale
- D Prattichizzo
Davis, T. Xss-10 micro-satellite flight demonstration, in: Proceedings of Georgia Institute of Technology Space Systems Engineering Confer-ence, paper no. GT-SSEC.D.3, Nov. 2005. de Pascale, M., Prattichizzo, D. The haptik library: a component based architecture for uniform access to haptic devices. IEEE Robot. Automat. Mag. 14 (4), 64–75, 2007
Time Domain Passivity Control of Haptic Interfaces A compact, light-weight, high data-rate antenna system for remote-sensing orbiters and space exploration DLR's robotics technologies for on-orbit servicing
- B Hannaford
- J.-H Ryu
- J Harder
- E Stoll
- M Schiffner
- M Pfeiffer
- U Walter
Hannaford, B., Ryu, J.-H. Time Domain Passivity Control of Haptic Interfaces. IEEE Trans. Robot. Automat., 2000. Harder, J., Stoll, E., Schiffner, M., Pfeiffer, M., Walter, U. A compact, light-weight, high data-rate antenna system for remote-sensing orbiters and space exploration, in: Proc. of 59th International Astronautical Congress, Glasgow, Scotland, 2008. Hirzinger, G., Landzettel, K., Brunner, B., Fischer, M., Preusche, C., Reintsema, D., Albu-Schä, A., Schreiber, G., Steinmetz, M. DLR's robotics technologies for on-orbit servicing. Adv. Robot. – Spl. Issue Service Robots Space 18 (2), 139–174, 2004.
Multimodal Human Spacecraft Interaction in Remote Environments – A new concept for free flyer control, chapter 1 Relative computer vision based navigation for small inspection spacecraft The hapticmaster, a new high per-formance haptic interface
- E Stoll
- A Saenz-Otero
- B Tweddle
- B E Tweddle
Stoll, E., Saenz-Otero, A., Tweddle, B. Multimodal Human Spacecraft Interaction in Remote Environments – A new concept for free flyer control, chapter 1. Springer, 2010. Tweddle, B.E. Relative computer vision based navigation for small inspection spacecraft, in: Proc. of AIAA Guidance, Navigation and Control Conference, Portland, 2011. van der Linde, R.Q., Lammertse, P., Frederiksen, E., Ruiter, B. The hapticmaster, a new high per-formance haptic interface, in: Eurohap-tics, Edinburgh, UK, 2002.
Proceedings of ICRA '00 Human Factors Institute Pongrac, H. Kooperation i2 -m6 -m5: Untersuchung von zeitverzö gerung mittels satellitenlink Teleoperation concepts in minimal invasive surgery ROKVISS – Preliminary Results for Telepresence
- M Oda
Oda, M. Experiences and lessons learned from the ets-vii robot satellite, in: Proceedings of ICRA '00. IEEE International Conference on Robotics and Automation, vol. 1, pp. 914–919, 2000. Pongrac, H. Gestaltung und Evaluation von virtuellen und Teleprä-systemen an Hand von Aufgabenleistung und Prä. PhD thesis, Human Factors Institute, Universitä der Bundeswehr, 2008. Pongrac, H. Kooperation i2 -m6 -m5: Untersuchung von zeitverzö gerung mittels satellitenlink. Technical report, 2008. Preusche, C., Ortmaier, T., Hirzinger, G. Teleoperation concepts in minimal invasive surgery. Control Eng. Practice 10, 1245–1250, 2002. Preusche, C., Reintsema, D., Landzettel, K., Hirzinger, G. ROKVISS – Preliminary Results for Telepresence. In proc. of the International Conference on Intelligent Robots and Systems (IROS), Peking, China, 2006.
Paving the way for a european data relay satellite (edrs), operational mission: the challenge ahead
- M Wittig
- R Bierett
- P Mancini
- C Elia
Wittig, M., Bierett, R., Mancini, P., Elia, C. Paving the way for a european data relay satellite (edrs), operational mission: the challenge ahead, in: Proc. of 59th International Astronautical Congress, Glas-gow, Scotland, 2008.
Assessment of frequency bands for data transmission, rt-da - 2004-01, diploma thesis, institute of astronautics, technische universität münchen
- P Vrancken
Vrancken, P. Assessment of frequency bands for data transmission, rt-da -2004-01, diploma thesis, institute of astronautics, technische universi-tä mü nchen. Master's thesis, Diploma Thesis, Institute of Astronau-tics, Technische Universitä Mü nchen, 2004.
DARPA Davis, T. Xss-10 micro-satellite flight demonstration, in: Proceedings of Georgia Institute of Technology Space Systems Engineering Confer-ence, paper no The haptik library: a component based architecture for uniform access to haptic devices Artemis data relay payload data book
- M Prattichizzo
//www.spaceflightnow.com/news/n0901/ 14dsp23/>, 2009. DARPA. <http://www.darpa.mil/Our_Work/TTO/Programs/Phoe-nix.aspx>, 2012. Davis, T. Xss-10 micro-satellite flight demonstration, in: Proceedings of Georgia Institute of Technology Space Systems Engineering Confer-ence, paper no. GT-SSEC.D.3, Nov. 2005. de Pascale, M., Prattichizzo, D. The haptik library: a component based architecture for uniform access to haptic devices. IEEE Robot. Automat. Mag. 14 (4), 64–75, 2007. Dessoy, D. 2003. Artemis data relay payload data book. Technical Report DTOS-REDU-IOT-BR-3003-OR, European Space Agency, Station Redu. D.Waltz 1993. On-Orbit Servicing of Space Systems. Krieger Publishing. Co.
Communication-induced disturbances in haptic telepresence systems Lane, J.C. Human Factors Optimization of Virtual Environment Attri-butes for a Space Telerobotic Control Station Effects of time delay on telerobotic control of neutral buoyancy vehicles
- M Kuschel
- S Hirche
- M Buss
- J C Lane
- C R Carignan
- B R Sullivan
- D L Akin
- T Hunt
- R Cohen
Kuschel, M., Hirche, S., Buss, M. Communication-induced disturbances in haptic telepresence systems, in: Proceedings of the IFAC World Congress, 2005. Lane, J.C. Human Factors Optimization of Virtual Environment Attri-butes for a Space Telerobotic Control Station. PhD thesis, University of Maryland, 2000. Lane, J.C., Carignan, C.R., Sullivan, B.R., Akin, D.L., Hunt, T., Cohen, R. Effects of time delay on telerobotic control of neutral buoyancy vehicles, in: IEEE Int. Conf. Robot. Automat., Washington, USA, 2002.
Testbed for telepresent on-orbit satellite servicing Bilateral energy transfer in delayed teleoperation on the time domain
- J Artigas
- P Kremer
- C Preusche
- G Hirzinger
- J Artigas
- C Preusche
- G Hirzinger
- G Borghesan
- C Melchiorri
Artigas, J., Kremer, P., Preusche, C., and Hirzinger, G. Testbed for telepresent on-orbit satellite servicing, in: Proceedings of the Human-Centered Robotic Systems Conference (HCRS), Munich, Germany, 2006. Artigas, J., Preusche, C., Hirzinger, G., Borghesan, G., and Melchiorri, C. Bilateral energy transfer in delayed teleoperation on the time domain, in: Proceedings of IEEE/RSJ International Conference on Robotics and Automation (ICRA'08), Pasadena, CA, USA, 2008. Covault, C. Secret inspection satellites boost space intelligence ops. Spaceflight Now – <http:
Demonstration of autonomous rendezvous technology (dart) project summary Automation and Human Supervisory Control Space teleoperation through time delay: review prognosis
- T Rumford
Rumford, T. Demonstration of autonomous rendezvous technology (dart) project summary, in: Proc. of Space Systems Technology and Operations Conference, Orlando, USA, Apr. 2003. Sheridan, T. Automation and Human Supervisory Control. MIT Press, Cambridge, 1992. Sheridan, T. Space teleoperation through time delay: review prognosis. IEEE Trans. Robot. Automat. 9 (5), 1993.
Secret inspection satellites boost space intelligence ops
- C Covault
Covault, C. Secret inspection satellites boost space intelligence ops.
Spaceflight Now – <http://www.spaceflightnow.com/news/n0901/
14dsp23/>, 2009.
DARPA.
<http://www.darpa.mil/Our_Work/TTO/Programs/Phoenix.aspx>, 2012.
Artemis data relay payload data book
- D Dessoy
Dessoy, D. 2003. Artemis data relay payload data book. Technical Report
DTOS-REDU-IOT-BR-3003-OR, European Space Agency, Station
Redu.
Xss-11 micro satellite -fact sheet, air force research laboratory, space vehicles directorate, doc. no. afd-070404-108, apr
AFRL 2007. Xss-11 micro satellite -fact sheet, air force research
laboratory, space vehicles directorate, doc. no. afd-070404-108, apr.
2007. Technical report, Air Force Research Laboratory, Space
Vehicles Directorate, doc. no. AFD-070404-108, Apr. 2007.
Xss-10 micro-satellite flight demonstration
- T Davis
Davis, T. Xss-10 micro-satellite flight demonstration, in: Proceedings of
Georgia Institute of Technology Space Systems Engineering Conference, paper no. GT-SSEC.D.3, Nov. 2005.
Relative computer vision based navigation for small inspection spacecraft The hapticmaster, a new high per-formance haptic interface
- B E R Q Tweddle
- P Lammertse
- E Frederiksen
- B Ruiter
Tweddle, B.E. Relative computer vision based navigation for small
inspection spacecraft, in: Proc. of AIAA Guidance, Navigation and
Control Conference, Portland, 2011.
van der Linde, R.Q., Lammertse, P., Frederiksen, E., Ruiter, B. The
hapticmaster, a new high per-formance haptic interface, in: Eurohaptics, Edinburgh, UK, 2002.