A description is given of research efforts directed towards the development of an active exploration system performing acquisition, processing, and integration of sensory inputs from vision, point laser range, tactile...
详细信息
A description is given of research efforts directed towards the development of an active exploration system performing acquisition, processing, and integration of sensory inputs from vision, point laser range, tactile, and force/torque sensors. An attempt is made to bring out the rationale that robotic workcell exploration can benefit by utilizing noncontact (e.g., vision, range, and proximity) as well as contact (e.g., tactile and force/torque) sensors while accomplishing tasks such as object identification, object localization, object grasping and object manipulation. The experimental results presented indicate that the rationale utilized in the design of the multisensory robotic active exploration scheme can work successfully.< >
A reference force-tracking impedance control system is proposed, consisting of a conventional impedance controller in the inner-loop and a trajectory modifying controller in the outer-loop for force-tracking. The desi...
详细信息
A reference force-tracking impedance control system is proposed, consisting of a conventional impedance controller in the inner-loop and a trajectory modifying controller in the outer-loop for force-tracking. The design of the outer-loop is presented and the stability of the two-loop control system is analyzed. A computationally efficient control algorithm for the inner-loop is suggested. Simulation results are presented. The controller is able to achieve excellent position and force-tracking with unknown environment stiffness and the presence of a burr on the tracking surface.< >
A parallel-jaw type multiple-d.o.f. robot hand is designed and implemented to manipulate workpieces within the hand by rotation and translation. An efficient manipulator control algorithm and part mating application i...
详细信息
A parallel-jaw type multiple-d.o.f. robot hand is designed and implemented to manipulate workpieces within the hand by rotation and translation. An efficient manipulator control algorithm and part mating application is developed. A simulation result is also presented to show the changes of force during part insertion to verify the models developed.< >
Dynamic segmentation is a method for improving the performance of cooperating tasks executed on loosely coupled multiprocessors. Four different data transfer techniques that can be used for intersegment data transfers...
详细信息
Dynamic segmentation is a method for improving the performance of cooperating tasks executed on loosely coupled multiprocessors. Four different data transfer techniques that can be used for intersegment data transfers in dynamically segmented buses are analyzed. Preemptive data transfers are considered for uniform message latencies and results are provided for message latency comparisons using various locality factors. These results indicate dynamic segmentation improves performance considerably, at a fraction of the cost of more complex interconnection networks such as multiple buses.< >
A new approach to solving the collision detection problem for mobile robots in the presence of moving obstacles is proposed. Both the robot and obstacles in the two-dimensional space are assumed to be polygonal and ar...
详细信息
A new approach to solving the collision detection problem for mobile robots in the presence of moving obstacles is proposed. Both the robot and obstacles in the two-dimensional space are assumed to be polygonal and are composed of a set of convex polygons. The half-plane representation uses an algebraic method to describe the object motion including translation and rotation through time. Compared with previous methods, the proposed representation is more general in that obstacles are now allowed to move at nonconstant velocities. To detect collision between polygonal objects, a traversability vector method was developed. Traversability vectors are a simple mechanism used to analyze geometric constraints imposed by polygons. Using these vectors, a simple algorithm for predicting collision is derived. computer simulations were conducted to show the feasibility of the proposed method.< >
The authors investigate dexterity measures of a manipulator based on its Jacobian matrix. The goal is to derive dexterity measures which can be used for both design and control of a manipulator. Generally, a dexterity...
详细信息
The authors investigate dexterity measures of a manipulator based on its Jacobian matrix. The goal is to derive dexterity measures which can be used for both design and control of a manipulator. Generally, a dexterity measure must be independent of the scale of a manipulator for design, and must be expressed analytically so that it can be used for real-time control. Every dexterity measure must bear a physical meaning. The measure of manipulability has an analytical expression, but it depends on the scale of a manipulator. On the other hand, the condition number is independent of the scale, but cannot be expressed analytically. These two main problems (scale dependency and analytical expression) of previous dexterity measures derived from the Jacobian matrix are solved and applied in design and control of manipulators. In addition, a dexterity measure called the measure of isotropy is introduced.< >
The authors present experimental results from a strategy for stable hard-on-hard impacts of a robot manipulator, and show how this method fits into the framework of force control. Previously proposed methods of impact...
详细信息
The authors present experimental results from a strategy for stable hard-on-hard impacts of a robot manipulator, and show how this method fits into the framework of force control. Previously proposed methods of impact control are reviewed, and their inadequacies are revealed. A fourth-order model of an arm/sensor/environment system is reviewed. It is pointed out how proportional gain force control with feedforward and impedance control are equivalent when the environment is stiff. An analysis of the model and the controllers shows the gain selection that provides the best impact response. Extensive experimental results confirm the correctness of the model, the equivalence of the controllers, and the efficacy of this impact control strategy.< >
An efficient planning algorithm for the organization and formulation of complete plans applicable to both robotic assemblies and intelligent robotic systems is proposed. The constraint of task precedence and the conce...
详细信息
An efficient planning algorithm for the organization and formulation of complete plans applicable to both robotic assemblies and intelligent robotic systems is proposed. The constraint of task precedence and the concepts of the criticality of tasks-events and valid repetitive orderings are introduced to facilitate and optimize the formulation of every complete plan capable of executing a user-requested job. Two examples demonstrate the applicability of the proposed algorithm to both robotic assemblies and intelligent robotic systems.
Sensing is one of the most essential aspects of any robotic application, be it manufacturing or any automated process. Robotic sensors can be divided into two classes of " internal " and " external &quo...
详细信息
Sensing is one of the most essential aspects of any robotic application, be it manufacturing or any automated process. Robotic sensors can be divided into two classes of " internal " and " external ". Examples of the first group are position or velocity, while the second group includes proximity, touch, or vision to name a few. The other important problem in manufacturing is interfacing with the environment within a cell. The object of this tutorial paper is to survey the two issues of "sensing" and "interfacing" in robotics and manufacturing.
An approach to intelligent PID (proportional integral derivative) control of industrial systems which is based on the application of fuzzy logic is presented. This approach assumes that one has available nominal contr...
详细信息
An approach to intelligent PID (proportional integral derivative) control of industrial systems which is based on the application of fuzzy logic is presented. This approach assumes that one has available nominal controller parameter settings through some classical tuning technique (Ziegler-Nichols, Kalman, etc.). By using an appropriate fuzzy matrix (similar to Macvicar-Whelan matrix), it is possible to determine small changes on these values during the system operation, and these lead to improved performance of the transient and steady behavior of the closed-loop system. This is achieved at the expense of some small extra computational effort, which can be very easily undertaken by a microprocessor. Several experimental results illustrate the improvements achieved.< >
暂无评论