Space Station Remote Manipulator Research Articles

Evaluation Criteria for Multi-Joint Arm Configuration in Space Robotics Operations

Providing adequate operational information to the International Space Station (ISS) robotics operators for overall arm configuration is critical for the operators' situational awareness in performing robotics tasks, especially when visual cues are limited. In this study, the Canadian Space Station Remote Manipulator System (SSRMS) is used as a demonstration model representing ISS robotics, and three evaluation indices for arm configuration in manual mode operation are proposed and examined in an example robotics operation. These indices will increase the operator's situational awareness in overall arm configuration, especially for monitoring the clearance of the arm with respect to the surrounding structures.

Canada and the International Space Station program: Overview and status

The twelve months since IAF 2000 have been perhaps the most exciting, challenging and rewarding months for Canada since the beginning of our participation in the International Space Station program in 1984. The highlight was the successful launch, on-orbit check out, and the first operational use of Canadarm2, the Space Station Remote Manipulator System, between April and July 2001. The anomalies encountered and the solutions found to achieve this success are described in the paper. The paper describes, also, the substantial progress that has been made, during the twelve months since IAF 2000, by Canada as it continues to complete work on all flight-elements of its contribution to the International Space Station and as we transition into real-time Space Station operations support and Canadian utilization. Canada's contribution to the International Space Station is the Mobile Servicing System (MSS), the external robotic system that is key to the successful assembly of the Space Station, the maintenance of its external systems, astronaut EVA support, and the servicing of external science payloads. The MSS ground segment that supports MSS operations, training, sustaining engineering, and logistics activities is reaching maturity. The MSS Engineering Support Center and the MSS Sustaining Engineering Facility are providing real-time support for on-orbit operations, and a Canadian Payloads Telescience Operations Center is now in place. Mission Controllers, astronauts and cosmonauts from all Space Station Partners continue to receive training at the Canadian Space Agency. The Remote Multi Purpose Room, one element of the MSS Operations Complex, will be ready to assume backroom support in 2002. Canada has completed work on identifying its Space Station utilization activities for the period 2000 through 2004. Also during the past twelve months the CSA drafted and is proceeding with the approval of a Canadian Space Station Commercialization Policy. Canadian astronauts have now participated in three ISS assembly missions - Julie Payette on STS-96, Marc Garneau on STS-97, and Chris Hadfield on STS-100 in April 2001 during which he performed Canada's first EVA and the successful installation of the Space Station Remote Manipulator System.

Neural network based dynamic modeling of flexible-link manipulators with application to the SSRMS

This paper presents an approach for dynamic modeling of flexible-link manipulators using artificial neural networks. A state-space representation is considered for a neural identifier. A recurrent network configuration is obtained by a combination of feedforward network architectures with dynamical elements in the form of stable filters. To guarantee the boundedness of the states, a joint PD control is introduced in the system. The method can be considered both as an online identifier that can be used as a basis for designing neural network controllers as well as an offline learning scheme to compute deflections due to link flexibility for evaluating forward dynamics. Unlike many other methods, the proposed approach does not assume knowledge of the nonlinearities of the system nor that the nonlinear system is linear in parameters. The performance of the proposed neural identifier is evaluated by identifying the dynamics of different flexible-link manipulators. To demonstrate the effectiveness of the algorithm, simulation results for a single-link manipulator, a two-link planar manipulator, and the Space Station Remote Manipulator System (SSRMS) are presented. ©2000 John Wiley & Sons, Inc.

Simulation of the SSRMS Dynamics for Payload Maneuvering and Berthing

The Mobile Servicing System (MSS) is a Canadian-built space robotics system that will play a major role in the assembly and maintenance of the International Space Station (ISS). The Space Station Remote Manipulator System (SSRMS), a major component of the MSS, is a robotic arm that will be used to relocate and install segments of the space station, logistics modules, and so on, in addition to providing a mobile support for EVA operations. This paper describes dynamic analyses and simulations that were performed by Spar Aerospace and the Canadian Space Agency using the Manipulator Development and Simulation Facility (MDSF) to verify feasibility and performance issues related to the maneuvering and berthing of the Science Power Platform (SPP) using the SSRMS. Several aspects of the operations are discussed including ability of the SSRMS to relocate itself on the Space Station, SPP hand-off from the Shuttle Remote Manipulator System (SRMS), and berthing of the SPP using the SSRMS Force Moment Accommodation (FMA) algorithm.

Canadian space robotic activities

The Canadian Space Agency has chosen space robotics as one of its key niche areas, and is currently preparing to deliver the first flight elements for the main robotic system of the international space station. The Mobile Servicing System (MSS) is the Canadian contribution to the international space station. It consists of three main elements. The Space Station Remote Manipulator System (SSRMS) is a 7-metre, 7-dof, robotic arm. The Special Purpose Dextrous Manipulator (SPDM), a smaller 2-metre, 7-dof, robotic arm can be used independently, or attached to the end of the SSRMS. The Mobile Base System (MBS) will be used as a support platform and will also provide power and data links for both the SSRMS and the SPDM. A Space Vision System (SVS) has been tested on Shuttle flights, and is being further developed to enhance the autonomous capabilities of the MSS. The CSA also has a Strategic Technologies in Automation and Robotics Program which is developing new technologies to fulfill future robotic space mission needs. This program is currently developing in industry technological capabilities in the areas of automation of operations, autonomous robotics, vision systems, trajectory planning and object avoidance, tactile and proximity sensors, and ground control of space robots. Within the CSA, a robotic testbed and several research programs are also advancing technologies such as haptic devices, control via head-mounted displays, predictive and preview displays, and the dynamic characterization of robotic arms. Canada is also now developing its next Long Term Space Plan. In this context, a planetary exploration program is being considered, which would utilize Canadian space robotic technologies in this new arena.

Effects of RCS Firing Constraints on the Remote Manipulator System of the Space Station

Two proposed approaches to reduce toads on the Space Station Remote Manipulator System induced by jet firings of the Reaction Control System are investigated. One approach is to extend the waiting period between successive jet firings; and the other is to adjust jet burn times so as to limit the anticipated linear and angular acceleration impulses at the manipulator base. Overall, superior results are obtained from impulse constraint approach and it can be augmented by the waiting period constraint if necessary.

237 Advanced control system features of the space station remote manipulator system

237 Advanced control system features of the space station remote manipulator system

Space robotics and manipulators — The past and the future

Abstract This paper presents the current state of the technology in space robotics. Some historical developments and the experience gained during those projects have been discussed. The challenge of space exploration and related danger requires even larger use of robotic devices. Many tasks and jobs are being automated. The exploration of the Moon and Mars requires autonomous, mobile robots to gather various information, measurements and data. The introduction of the Space Shuttle and related activities required an efficient robotic manipulator for in orbit operations. The Space Station Mir (in-orbit) and especially Space Station Freedom or Alpha (planned for the very near future) require advanced robots and manipulators. The Space Station Remote Manipulator System (SSRMS) and Special Purpose Dextrous Manipulator (SPDM) have been shown and briefly reviewed. Those and other robots for future missions are discussed in this paper.

Space Robotics and Manipulators: Lessons Learned From the Past and Future Missions and Systems

Abstract This paper presents the current state of the technology in space robotics. Some historical developments and the experience gained during those projects have been discussed. The challenge of space exploration and related danger requires even larger use of robotics devices. Many tasks and jobs are being automated. The exploration of the Moon and Mars requires the autonomous, mobile robots to gather various information, measurements and data. An introduction of Space Shuttle and related activities required an efficient robotic manipulator for in orbit operations. The Space Station Mir (in orbit) and especially Space Station Freedom (planned for nearest future) require advanced robots and manipulators. The Space Station Remote Manipulator System (SSRMS) and Special Purpose Dextrous Manipulator (SPDM) have been shown and briefly reviewed. Those and other robots for future missions are discussed in this paper.

Advanced Control System Features of the Space Station Remote Manipulator System

The Space Station Remote Manipulator System (SSRMS) is part of Canada's contribution to Space Station “Freedom“. This large manipulator will be used during the assembly and operation of the station to perform tasks such as the assembly of truss segments and pressurized modules, berthing the Shuttle Orbiter, and positioning EVA astronauts as well as the Special Purpose Dexterous Manipulator. This paper provides an overview of the role and configuration of the SSRMS and discusses the major SSRMS payload handling requirements. The SSRMS control systems and its operating modes are described, with focus on the Force/Moment Accommodation and the Artificial Vision systems. The utility of these advanced features is illustrated by simulation and test results

A kinematic analysis of the space station remote manipulator system (SSRMS)

AbstractAn efficient reverse analysis of three 6‐degree‐of‐freedom (dof) subchains of the 7‐dof SSRMS is presented. The first subchain is formed by locking the seventh joint. The second subchain is formed by locking the second joint, while the third subchain is formed by locking the first joint (the grounded joint is counted as the first joint in the chain). There are a maximum of eight different arm configurations in each of the three subchains, and these were determined by employing a computer‐efficient algorithm, which required the rooting of only at most quadratic polynomials. The algorithms were implemented, and the SSRMS was employed in an animated environment to perform and practice a number of useful tasks for space station servicing. The locking of the second joint has the advantage in that an operator could, at the outset, choose the orientation of the plane that contains the two longest links (the upper arm and forearm) so as to avoid collisions with obstacles. However, it has the disadvantage that when the second joint angle equals 0° or 180°, the manipulator is in a singularity configuration (a singularity analysis of the SSRMS is presented in a second article). It is interesting to note that this plane can also be oriented by specifying the first joint angle. This has the distinct advantage that the plane can be oriented arbitrarily and, in this way, the singularity is avoided.