For planar hinge four-bar closed kinematic chain the following is done:①several exact mathematic and verbal expressions of revolving pair condition are enumerated;
The spectrums of degree,structural component and multiple hinges are defined according to the basic parameters of planar closed kinematic chain with multiple hinges.
Using the closed kinematic chain and open chain, which are known and in which the quantity of components is less, the closed kinematic chain and open chain can be combined by the connecting joints of open chain.
According to the research about the closed spatial motion links 6R, RRPPRRand RCCR with a plane of symetry, the following results are obtained: the condi-tions under which the mechanisms above become overconstrained constant velocitybicrank mechanisms are equivalent to the crank existing conditions of the over-constrained mechanisms RRRE, RRPE and RCE respecdively.
After that, topological symmetry between joints in planar open and closed chain is discussed, and the method for identifying topological symmetry, and its application to type synthesis is studied.
The steering control mechanism used in all helicopters, including the CL-327, is a complex closed kinematic chain often called the swashplate mechanism.
However, one major problem in controlling this kind of manipulator is that, due to its closed kinematic chain and parallel-link constrained structure, it is impossible to derive an explicit kinematic solution.
In this Paper the direction cosine matrices and conditions of geometrical identities are applied to derive the crank existing conditions and the translation conditions about the output link of the mechanism for the overconstrained mechanisms RRRE, RRPE and RCE, Furthermore, the method is also applied to the spatial crank mechanisms with a single degree of freedom such as RRRRE,RRPRE and RCRE, which are similar to the mechanisms mentioned above inmotion character. Thus, the significance of the crank existing...
Spatial motion of a rigid body can be seen as a screw motion of the body along a specific axis. In accordance with the above principle the screw theory is presented to analyse the relative motion of a robot here. The screw motion equation presented is also suitable for closed chains, i. e. spatial mechanisms.
For planar hinge four-bar closed kinematic chain the following is done:①several exact mathematic and verbal expressions of revolving pair condition are enumerated;②existence condition and location of revolving pair in the chain are studied. The conclusions can be used to determine the type of each hinge pair in the chain rapidly and accurately;③classification of the chain is made according to revolving Pair condition, From this classification,all types of planar hinge four-bar linkage are found out.