To investigate the parameters of the protein design problem that we are exploring in collaboration with biochemists, we have developed a tool that uses inverse kinematics to support moving small fragments of protein backbone, while respecting biochemists’ desires to “remain in favorable regions of the Ramachandran plot” and “preserve ideal geometry”. By presenting estimates of derivatives in re...

This paper presents the results of rubbertuator modeling for purposes of control applications. A pair of rubbertuators is constructed as a revolute joint. The rubbertuator arm is highly nonlinear and exhibits hysteresis. The frequency modeling method was implemented using software agents within the Intelligent Machine Architecture (IMA) framework. Several linear models were built, simulated, an...

Creating highly articulated miniature structures requires assembling a large number of small parts. This is a very challenging task and increases cost of mechanical assemblies. Insert molding presents the possibility of creating a highly articulated structure in a single molding step. This can be accomplished by placing multiple metallic bearings in the mold and injecting plastic on top of them...

In this paper a new example of a hopping robot is considered, consisting simply of two links (the end of one link acts as the foot) joined by an actuated, revolute joint. For the stance phase a nonlinear controller is derived that maintains the balance o f t h e robot and periodically accelerates the center of mass vertically. For large enough oscillations the robot can slide or take off. If fl...

This paper presents a simple procedure that can be used to determine the stiffness matrix of 6R serial manipulator in selected points of the work space with joint stiffness coefficients taking into account. Elastokinematical model for the robot manipulator FANUC S-420F was considered as spatial and serial kinematical chain composed of six rigid links, connected by ideal revolute joint (without ...

This paper proposes design strategies and a comparative study of two antagonistically actuated tensegrity joints: revolute (R) joint an anti-parallelogram (X) joint. Geometrically, the R-joint has fixed center rotation while X-joint moving rotation. Both joints are equipped with lateral springs by cables passing through these springs. Such can be interest for developing lightweight manipulators...

This paper suggests and employs a method for reducing vibrations at the tip of a robot. The vibrations, caused by structural flexibility, are detected using accelerometers. The robot control system consists of two complementary sub-systems: a nominal motion controller and a vibration compensator. The former one realizes joint motions in accordance with a prescribed tip trajectory. The latter on...

This study presents a comparison of different control laws for the trajectory control of a revolute-jointed manipulator. For this purpose, adaptive, robust and sliding mode control algorithms are applied to the model system so as to reduce tracking error at each joint. It is assumed that robot parameters are not known exactly and the system includes some uncertainties and disturbances. Computer...

This paper studies motion planning from one zero velocity state to another for a three-joint robot in a horizontal plane with a passive revolute third joint. Such a robot is small-time locallycontrollableon an open subset of its zero velocity section, allowing it to follow any path in this subset arbitrarily closely. However, some paths are “preferred” by the dynamics of the manipulator in that...

This paper discusses the identification of dynamic parameters of an industrial robot KUKA KR5 with all revolute joints and serial architecture. For this, the simplified model of the robot was taken into account by considering only those joints which normally operates orthogonal to the gravity vector. The first approach used for finding the dynamic parameters of this simplified model was by form...