The active hydraulic mount with solenoid actuator (AHM-SNA) does not require permanent magnets, is of low cost, and has attracted wide attention. This paper focuses on each link of the secondary path in AHM-SNA, the transfer functions (TFs) were studied one by one, and a simple and efficient expression for the total secondary path is discussed. First, based on the mathematical model of the hydraulic mount with inertia track and decoupling membrane, the TF from actuator active force to output force at frame side was analyzed, the results show that the TF was constant in the mid-frequency band. Second, based on the geometric parameters and cone air gap of solenoid actuator, it was obtained that the TF from the square of current to actuator active force is also constant; based on the relationship that the active force frequency is twice of the harmonic current frequency, the full-wave-rectified current was introduced. Utilizing the fact that the second harmonic component of the current is the main component, it was concluded that the total TF of the secondary path from current to active force and then to output force at frame side was constant in the mid-frequency band. Finally, two sets of experiments with full-wave-rectified current as the excitation were carried out, and the analytical conclusion was verified that the TF of the secondary path was constant as a proportional link and was convenient for the active control algorithms.

Based on the units of single-opened-chain limb, some topological characteristics of rank-degenerate parallel robot mechanisms are revealed, and a systematic and effective new method for structure synthesis of 4-DOF (3-translation and 1-rotation) parallel robot mechanism is put forward in this paper. 50 new mechanisms are synthesized and classified. The method proposed in this paper is of universal significance and has been used for the structure synthesis of rank-degenerate parallel robot mechanisms with other kinematics output types.

Based on the units of single-opened-chain limb, some topological characteristics of rank-degenerate parallel robot mechanisms are revealed, and a systematic methodology for the structural synthesis of a class of five degree-of-freedom parallel robot mechanisms is put forward in this paper. 49 new mechanisms with three translational and two rotational degrees of freedom are synthesized and classified. The method proposed in this paper is of universal significance and has been used for the structure synthesis of rank-degenerate parallel robot mechanisms with other kinematics output types.

This paper presents a new viewpoint about structural composition of spatial kinematic chains; single-opened chains are regarded as basic structural units of mechanisms. The constraint characteristics (the constraint factors, Δj) of single-opened chains and the constraint characteristics (the coupled degree, κ and the κ-algorithm) of mechanical networks are presented. Thus a kinematic chain with ν independent loops is regarded to be composed of one basic link and ν single-opened chains in regular sequence. The above mentioned topological characteristics are used for setting up a new unified model for structural analysis and synthesis, kinematics and dynamics of spatial mechanisms.

Based on the single-opened chain constraints and the network topological characteristics of mechanisms, a powerful new method for structural synthesis of spatial kinematic chain with plane and nonplane linear graphs has been developed. This permits the development of a highly efficient and completely automatic program for the computer-generated enumeration of structural types of mechanisms. The method is illustrated by applying to the case of kinematic chains with up to six independent loops on a personal computer.