A family of reconfigurable parallel robots can change motion modes by passing through constraint singularities by locking and releasing some passive joints of the robot. This paper is about the kinematics, the workspace and singularity analysis of a 3-PRPiR parallel robot involving lockable Pi and R (revolute) joints. Here a Pi joint may act as a 1-DOF planar parallelogram if its lockable P (pr...

Compared with the serial mechanism, the parallel mechanism has many advantages. Using the parallel mechanism as the basic leg mechanism of a walking robot, not only the payload-weight ratio can be improved, but also the robot walking stability and security performance can be enhanced. By combining the kinematics features of 3-UPU parallel mechanism with the structural features of the quadruped ...

Concentrated solar power (CSP) plants are expansive facilities that require substantial inspection and maintenance. A fully automated inspection robot increases the efficiency of maintenance work, reduces operating and maintenance costs, and improves safety and work conditions for service technicians. This paper describes a climbing robot that is capable of performing inspection and maintenance...

Aircraft fuel tank leakage is a very common maintenance problem. A continuum robot is designed for troubleshooting of leaks for fuel tank which has strong constraints and is also explosive. The biomimetic robot with several flexible sections applies actuation redundancy through pulling its four independent driving cables to realize bending motion of two degrees of freedom (DOF). The forward kin...

This paper presents an elegant contact dynamics model in screw bondgraph form. It can model the contact between any two objects of finite curvature. It does so by defining a Gauss frame on the surfaces of both objects in the points that are closest to each other. Then it describes how the Gauss frames move as the objects move relative to each other. This is called the contact kinematics. The co...

This paper presents a novel compact design for a two degrees of freedom (DOF) joint mechanism. The joint is optimized for compactness, strength and range of motion which makes it ideal for constructing spatial or three-dimensional hyper redundant robots. We also identify and classify various prior joint designs that led to the development of this new concept. Finally, we present the joint forwa...

The parallel robots seem to be one of the promising ways to improve accuracy and speed. At their development some new problems appear. This paper deals with design of direct kinematics for real-time path control of planar redundant parallel robots. The main reason for its using is a fact that the direct kinematics gives possibility to use Cartesian coordinates as against joint ones and by this ...

After writing programs for a production robot, an operator must manually teach hundreds or thousands of poses. Teaching poses is extremely time consuming and, unfortunately, periodic reteaching is necessary. The need to reteach is commonly due to: wear, repair, slight movements of workpieces, or replacement of the robot and its tools. Our experience has shown that conventional methods of adjust...

This paper studies modeling of tangential compliance as two rigid bodies collide in the space. Stronge’s spring-based contact structure [13, pp. 95-96] is extended to three dimensions. Slip or stick is indicated by the tangential motion of a massless particle connected to the contact point (viewed as an infinitesimal region) on one body via three orthogonal springs. We show that the effect of t...

In this study, a new adaptive synchronized tracking control approach is developed for the operation of multiple robotic manipulators in the presence of uncertain kinematics and dynamics. In terms of the system synchronization and adaptive control, the proposed approach can stabilize position tracking of each robotic manipulator while coordinating its motion with the other robotic manipulators. ...