Singularity is a basic problem for parallel mechanism design because of its many negative influences on the mechanism performances. Traditionally, three kinds of singularities are suitable for analysis of the parallel mechanisms. By considering both the common and redundant actuation parallel mechanisms, general kinematic model is used to obtain input factor matrix and output factor matrix. Based on ranks of the two matrices, the singularity type becomes easy to judge. And the second kind of singularity can be reduced or eliminated by adding special redundant actuation sub-chains. A two-degree-of-freedom parallel mechanism is provided to illustrate the method about how to create the needed redundant actuation sub-chains.

No abstract

At present, most of the robots’ intelligent level is not as high as needed and they can’t accomplish some special tasks successfully under complicated circumstances. A kind of robot master-slave control system based on LabVIEW is designed, which allows operators control robots working in dangerous environment such as high radiation, ultrahigh temperature through outside input device. The device should connect with the master computer. This kind of operation mode can not only make full use of human intelligence, but also exploit the robots’ ability of being able to work in the abominable environments, making human and the robot fully complement each other's advantages. At the same time, the robot master-slave control system based on LabVIEW is easy to develop and maintain for its good portability and scalability.

Garbage cleaning robot will gather and process most of the garbage under certain circumstance for people. It can economize labor, enhance efficiency and improve the working environment. Unfortunately, most garbage-gathering devices of these mechanisms are singular and can be used for only one kind of environment as far as the land and water conditions are concerned. A kind of new amphibian garbage cleaning robot is brought forth and analyzed from three aspects, including mechanical structure, control system and programming method. And prototype of the robot is given. Analysis shows that this robot can directly move either from water to land or from land to water and above all, the robot has the advantage of low cost, long duration, better rigidity and convenient to operate.

The singular configurations of a type of redundantly actuated parallel manipulator are studied in view of manipulability. Considering the non-square characteristics of Jacobian matrix of redundant input parallel machine, Laplace Theorem and its correlative theorems in Matrices Theory are introduced to avoid the problem that there is no determinant for non-square matrix. Singularity configuration distribution characteristics of this redundant input parallel machine are also depicted for different surfaces and orientations. These results provide pivotal foundations for its valid workspace selection.