Search

According to the combination of lower limbs rehabilitative robot (LLRR), the effect of multi-point and single point driving form on muscle force and joint torque is explored, and the rehabilitation effect of the training mode of the active–passive rehabilitation training is studied. The musculoskeletal model of lower limbs is established based on the physiological structure of human lower limbs. And considering the position of the attachment points of each muscle, the mechanical properties of muscles and applied moment of joints can be obtained under different rehabilitative training strategies by inverse dynamic analysis. The rehabilitation training strategies of flexion–extension and abduction and adduction movements are put forward according to the movement of lower limbs. And using the wire-driven rehabilitation robot as the driving device of the rehabilitation training, the robot is used to simulate the motor function of patients’ lower limbs by modifying the parameters of muscle which can affect the resistance moment of joint motion, then the effects of driving form and the active–passive training mode are analyzed. The results show that single point driving form is better than multi-point on muscle strength and joint strength training; the rehabilitation training strategies of flexion–extension and abduction–adduction movements show different superiority.

The purpose of the research is to investigate into characteristics of deformation in thrust system which reduces the stiffness with the increase of displacement for piston in hydraulic cylinder. Firstly, based on the hyperstatic compatibility, the spatial deforming ellipse for the driving system has been discovered. Then the characteristics for the deforming ellipse of even and non-uniform arrangement systems have been analyzed in detail. Finally, applying deforming ellipse to the thrust systems of a shield machine in engineering applications, the characteristics of the deforming ellipse affected the behavior of the thrust system have been discussed. The result could provide a theoretical foundation and support for the design of thrust systems in shield tunneling machines.

In order to build an linear, high computational efficiency geometric error model for machine tools, a new error modeling method based on screw theory is presented. Geometrical error sources are expressed as error twists, and the integrated model is calculated as the sum of error twists. The method is demonstrated on a 2-DOF mechanism and a simulation error modeling procedure at 1000 random points for a 5-axis machine tool is conducted. The simulation results show that the computational efficiency increase by 5 times. The feasibility of the proposed method is also verified and the physical influences of the error sources are also analyzed. This modeling method has high computational efficiency and clear physical meanings. It is useful to guide the design of new machine tools.