The Specifics of Calculating the Efficiency of the Continuously Variable Mechanical Transmission with Oscillatory Movement of Internal Links and Force Function Control

The paper discusses the energy flow in the continuously variable mechanical transmission with oscillatory movement of internal links and force function control. It is proposed to treat the potential energy of the twisted torsion bars, which is transferred back to the drive shaft, as useful. The formula for calculating the transmission efficiency, taking into account the return of energy flow back to the motor, hysteresis losses, and energy dissipation in the mechanical rectifier while taking up the free play, is given. When calculating the efficiency of the continuously variable mechanical transmission, it is suggested to take into consideration the clearances in the rectifier and kinematic pairs using ‘kinematic efficiency’. The examples of measured and calculated transmission efficiency in the ‘stop’ mode are given.

A ZONOTOPE-BASED APPROACH FOR MANIPULABILITY STUDY OF REDUNDANT ROBOT LIMBS

Kinematic efficiency of robot limbs can be analyzed by means of the manipulability concept defined by Yoshikawa. However, when it is applied to redundant serial chains, that are the most common case in humanoid robotics, Yoshikawa's manipulability measure is not able to take into account the joint velocity range of each robot joint. In order to overcome this difficulty we propose to substitute in the place of the manipulability ellipsoid a manipulability zonotope resulting from the robot Jacobian transform of the joint velocities parallelotope. The proposed manipulability zonotope notion is similar to the well-known manipulability polytope notion, but its associated volume measure can take benefit of the so-called zonotope theory. By means of a famous and powerful theorem about the cubical dissection of any zonotope, an original formula of manipulability measure is proposed from which is also derived a mean manipulability estimate associated to a given joint space working. The proposed tools are applied to a kinematic analysis of a 4R-regional structure model of the upper limb.

Research of the Joint Workspaces and Kinematic Efficiency of Man-Machine Systems of Bicycles

Bicycle design largely contradicts human motion, necessitating consideration of both the bicycle structure and the kinematic efficiency in the dimensions of the rider’s limbs, as well as human factor engineering, i.e. comfortability. By focusing on the kinematic model of 5-bar linkage and joints workspace, this study examines the most appropriate bicycle design and the riding posture to ensure that muscles can produce the effective moment and increase driving efficiency of a crank necessary. For upright, racing and recumbent bicycle types, assumptions are made regarding mobility analysis and the system of man-machine systems of bicycles estimated as well. Simulation results can identify the major dimensions of bicycle designing for different riders efficiently by inputting physical measurements of the rider and the angle range of driving force, subsequently increasing the riding efficiency to decrease the load of lower limbs of riders and satisfying ergonomic requirements of bicycle riders.