A novel spatial parallel manipulator designed to assemble diagnostic instruments in SG-III is introduced in this paper. Firstly, resorting to screw theory, mobility analysis is presented for this manipulator. Then, the inverse KINEMATICS problem is determined by the method of RPY transformation with the singularity analyzed. As a key issue in parallel manipulators, it is more di cult to solve the FORWARD KINEMATICS problem, since it is highly nonlinear and coupled. In this work, three di erent approaches are presented to deal with this issue, namely, the back propagation neural network, the simpli ed ant colony optimization, and the proposed improved Newton iterative method. Simulation of each approach is conducted, and their merits and demerits are compared in detail. It is concluded that the improved Newton iterative method, which can provide good initial iteration values, shows the best performance in estimation of the nonlinear FORWARD kinematic mapping of the considered parallel manipulator.

The FORWARD position KINEMATICS (FPK) of a parallel manipulator with new architecture supposed to be used as a moving mechanism in a flight simulator project is discussed in this paper. The closed form solution for the FPK problem of the manipulator is first determined. It has, then, been shown that there are at most 24 solutions for FPK problem. This result has been verified by using other techniques such as geometric approach and a numerical method known as polynomial continuation. Numerical examples are performed to display all possible solutions available for the devised manipulator.

Purpose: FORWARD Walking (FW) and Backward Walking (BW) on different gradients of the treadmill is a common exercise for lower extremity rehabilitation. However, limited studies are found about the three-dimensional analysis of lower extremity and status of the knee joint during FW and BW on different gradients. Therefore, this study aimed to investigate the lower extremity joints KINEMATICS during FW and BW on incline and decline surfaces.Methods: The current research has a quasi-experimental design. Sixteen healthy males with the mean (SD) age of 22.4 (2.5) years, volunteered to participate in this study. The subjects’ FW and BW with their preferred speed on a treadmill at four gradients (-7.5%, 0%, +5% and+10%), were analyzed by using motion capture system. All data were analyzed using paired sample t test (P<0.05).Results: Significant differences were seen between FW and BW in most angular variables in sagittal plane. However, there were no significant differences between FW and BW in most parameters of knee angle in frontal plane.Conclusion: Based on the results, with increase in FW inclination and decrease in BW inclination, the knee varus angle in frontal plane reduces. Therefore, FW on the upslope surfaces or BW on downslope surfaces, probably is a suitable solution to reduce the loads exerted on medial compartment of the knee.

In this paper, a novel spatial six-degree-of freedom parallel manipulator actuated by three base-mounted partial spherical actuators is studied. This new parallel manipulator consists of a base platform and a moving platform, which are connected by three legs. Each leg of the manipulator 'is composed of a spherical joint, prismatic joint and universal joint. The base-mounted partial spherical actuators can only specify the direction of their corresponding legs. In other' words, the spin of each leg is a passive degree-of-freedom. The inverse pose and FORWARD pose of the new mechanism are described. In the inverse pose pneumatics, active joint variables are calculated with no need for evaluation of the passive joint variables. To solve the FORWARD pose problem, a much simpler method compared to the traditional method is introduced. Closed form relations for the inverse and FORWARD and KINEMATICS are proposed. Finally, two sets of singular consignation of the newly introduced manipulator with different natures are obtained.