The Structure And Kinematics Design Of Lower-Mobility Parallel Teaching Robot

The parallel kinematics machine (PKM),a robot mechanism, has the characteristics of high structure rigidity, high speed, and high exactitude. Because of the structure complicated, difficult to be controled and a lot of key technology not to be settled, parallel mechanism of 6 freedom has not used widely in project reality. Short freedom parallel mechanism has already become a new focus on robot study at present in reasons of simple structure and fabrication cost. This text combine new centuries educate reform in education project "study and practice teaching synthesize mechanical basic theory teachings and practice" sub projects" parallel teaching robot the developments of device". We design a parallel mechanism of short freedom that satisfy the request of degree of freedom. And have studied on type synthesize method of parallel mechanism. We also analyse the relations of export freedom of working up platform and sub-chain of parallel mechanism.The relations of freedom of working up platform and sub-chain of parallel mechanism. We have analysed several kinds of sub-chain by Spiral theory. And on the basis of that, study the relations of the degree of freedom of chain of the sport of organization branch and relation of moving the degree of freedom of the platform of parallel mechanism. We have drawn some general conclusions.The mechanism design of parallel mechanism is to get the possible mechanism by virtue of the mechanism function. In order to get all possible structure type of arganization of satisfying design task request, all parallel mechanism comprised of basically pairs have be calculated according to the equation of the degree of freedom in parallel mechanism. The method to utilize vice substitution of sport, is substituted these by a pair of sport chain formed basically, in order that we obtain parallel mechanism structure type of application of the project. And according to the type of drive pair and its factors such as positions of sub-chain etc. of one, the structure type of parallel mechanism have been screened tentatively. As to parallel mechanism of degree of freedom 6, because the degree of freedom of its sub-chain will certainly be greater than equaling by 6, those sub-chain which satisfy this condition can be maked up in order to obtain needed structure type of parallel mechanism.Parallel mechanism of short degree of freedom hope that some unexpected export sport is constant. So we need use Spiral theory to analyse degree of freedom association type of parallel mechanism. In this paper, we introduce design method of short degree of freedom of parallel mechanism on single Open chain. And with subject need, we analyse degree of freedom association type which satisfy design task request. A kind of degrees of freedom 5 parallel mechanism which fulfill requirements has been designed on the basis of the method of pair substitutions.In this paper, as to parallel mechanism of degree of freedom 5, towards and inverse position problem have been studied and their model has been set up. And we have calculated inverse position problem of parallel mechanism. Preliminary research should connect the performance index of parallel mechanism. And we has analysed its singularity.