The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We have succeeded in utilizing In–Ga–Zn–O (IGZO) thin-film devices as synapse elements in a neural network. The electrical conductance is regarded as the connection strength, and the continuous change by flowing electrical current is employed as the connection plasticity based on the modified Hebbian learning as a learning rule. We developed a cellular neural network using the IGZO thin-film devices...
We are developing cellular neural networks using thin-film transistors (TFTs). Although simplification of the circuits for the neurons and synapses is also needed for the cellular neural network, the detailed discussion is not sufficient for the cellular neural network. Particularly in this study, we tried simplification of synapse devices. We used discrete trimmer resistors and capacitors for the...
We are developing cellular neural networks using thin-film transistors (TFTs). Although simplification of the processing elements such as neurons and synapses is also needed for the cellular neural network, it is difficult and time-consuming to fabricate and evaluate actual devices. Therefore, we are studying the simplification of the processing elements in the neural networks by using circuit simulation...
This paper discusses the dynamics of a tether-based mobile robot in space. The tether-based mobile robot is constrained geometrically using several tethers and can move within an area bounded by the tethers' anchors by changing the tethers' lengths. This robot is equipped with an extendable and retractable arm that approaches the tethers' anchor and reposition it to another point for changing the...
This paper presents the impedance-based contact control of a free-flying space robot utilizing a compliant wrist for non-cooperative satellite capture operation. An open loop impedance control law based on contact dynamics model is introduced to realize a desired coefficient of restitution defined between a manipulator hand of a space robot and a contact point on a free-flying target. The coefficient...
This paper presents an impedance-based contact control of a free-flying space robot with respect to the coefficient of restitution. Since no object is constrained in space, the contact between two objects in orbit must be treated carefully so as to prevent the objects from inducing undesired contact force and post-contact relative motion. As a solution to this issue, the authors propose a contact...
This study addresses a time-optimal control of a free-floating space robot to stabilize a tumbling target satellite while paying attention to: 1) limitations on the grasping force and torque, 2) detumbling operation along an arbitrary arm motion, and 3) parameter uncertainty in the target satellite, by parameterizing the manipulator hand motion. The concept of detumbling speed, determines the optimal...
This study addresses a time-optimal control of a free-floating space robot to stabilize a tumbling target satellite while paying attention to: 1) limitations on the grasping force and torque, 2) detumbling operation along an arbitrary arm motion, and 3) parameter uncertainty in the target satellite, by parameterizing the manipulator hand motion. The consept of detumbling speed, determines the optimal...
On-ground experiment for space robotic system is essential to validate constructed robotic system prior to launch. This paper presents an integrated on-ground experimental environment for orbital robotic system. The experimental environment utilizes an air-floating testbed to realize two-dimensional micro-gravity environment on ground. As manipulation system, the constructed environment adopts a ground-based...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.