Based on the constrained equations of velocity of two arm robotic mechanisms,by using the principle of supersition and the recursive formulation,it is established that the constrained equations of acceleration for two arm robotic mechanisms in the process of coordinate motion.

A control strategy based on velocity constraints was introduced.

Based on velocity constraint and position constraint,two control strategies of the Cobot were respectively given out,which both have passive and constraint characteristics.

Based on the theory of coupling and constraint equation, the paper puts forward a Finite Element model (FEM) of metallic hose with the element of Shell93 and Beam189.

Then,the displacement relation between the nodes in one beam is made up by the constraint equation method.

The constraint equations were established at the common boundary section based on plane section premise.

The rationality of end constraint equations on buckling loads of a drillstring in an inclined wellbore is investigated.

In the new approach, the method of regula falsi is used to solve the constraint equations, instead of the conventional linear approximation.

The motion of the rolling disk was analysed to try to explain some unintegrable equations of constraint which is not definitely independent equation of nonholonomic constraint,and the concept of concealed coordinate was proposed.

The equations of constraint are concerted with ideal constraints.

This article analyses the motion of the rolling disk,trying to explain some unintegrable equations of constraint which is not definitely independent equation of nonholonomic constraint,and put forward the concept of concealed coordinate.