Papers by Keyword: Harmonic Drive

Abstract: To suppress the abrupt and unexpected turning velocity fluctuation of the industrial robot under the condition of trajectory tracking, a flexible robotic joint experimental setup with the harmonic drive was established. The measured friction with Stribeck effect and velocity were modeled by a simple polynomial fit method. Two friction compensation control strategies of feedforward and feedback were designed. The friction compensation experiments were carried out on the dSPACE system, the good restraint effect of fluctuation on the turning velocity was verified and the control accuracy of feedback compensation control strategy proved better.

Abstract: The paper deals with the improvement of quality control system harmonic drive with servo applying the method of compensation torque oscillations. The method consists of applying the rejection block. Post documents the oscillatory nature of the system servo-harmonic transmission. Described the reduction block connected to this system suppresses the oscillation of torque, speed and position of the harmonic drive output shaft thereby improving the quality of the regulatory process.The papers solves the problem of torque oscillations of the system which consist of servomotor and harmonic drive. Described rejection filter connected to the input of the system damps oscillations and increases the quality of control.

Abstract: The author of the article applied the boundary element method (BEM) to determine stresses occurring in a toothed rim of a flexspline. The relevant numerical calculations were conducted using software developed at the Faculty of Transport of the Silesian University of Technology. The numerical analysis conducted for flexsplines entailed the impact exerted by parameters of an indented toothed flexspline rim (number of teeth, addendum modification coefficient) and of a gear tool (gear tool head curve radius, pressure angle) on values of the stresses occurring at the tooth space bottom. Results of the said calculations have been depicted as curves of dependences between stresses at the tooth space bottom in the function of the number of flexspline rim teeth on constant values of the addendum modification coefficient. The cumulative diagrams developed based on the results of the calculations conducted may provide guidelines as to the manner of designing flexsplines for harmonic drives.

Abstract: A methodology to calculate the meshing tooth of giant magnetostrictive harmonic motor is proposed in this paper. The deformation curve of the flex spline of the giant magnetostrictive harmonic motor was investigated with Fourier function. A kinematic model of harmonic drive was established when the involute profile is selected as the flexible gear tooth shape and the circular spline is obtained following the envelope theory, thereby generating the kinematic simulation as well as the trajectory of the circular spline teeth with respect to the flex spline. Finally, the relationship between the cone angle of flex spline and the engagement profile is discussed; together with an improvement strategy-equal width shrinkage of circular spline.

Abstract: The gear teeth have influence on the stresses in flexspline, through the influence coefficients of gear tooth of flexspline. For the purpose of theoretically clarifying this influence, the profile of the gear tooth of the flexspline is simplified as two simple shapes of rectangle and trapezoid. The gear tooth influence on the stresses in the flexspline has been studied and analyzed on this two cases, and the two simplified tooth profiles of rectangle and trapezoid have been compared with each other.

Abstract: This paper is focused on the micro harmonic drive with a planet type wave generator in which flexspline consists of internal and external gear rings. The mathematical relationship between the coordinates of the points on the tooth profile of the deformed flexspline and that of the undeformed flexspline is derived by carrying on the coordinates transformation. According to this mathematical relationship, the coordinates of the points on the both sides of the tooth profile of every gear tooth of the one forth of the internal and external gear rings of the deformed flexspline are solved with the use of the mathematical software, then the coordinates are imported into the software Pro/E, and connect in a correct order with spline curves, the two curves have been mirrored and extended to finish the 3D modeling of the deformed flespline. At last, the FEM analysis of the deformed flexspline has been carried out.

Abstract: On the basis of a transmission error-testing laboratory bench which is designed in advance, the research and design of a transmission error-testing system of harmonic drive are carried on. The structural composition and test principle of this testing system are introduced. Based on the software, LabView2009, the design of the transmission error-testing system of harmonic drive is finished. With the help of this testing system, the following purposes can be realized. The input and output angle data of the harmonic drive can be acquired, its transmission error is capable of being analyzed and the data will be able to be stored.

Abstract: To meet the demand of joint torque measurement for a modular reconfigurable robot, a harmonic drive built-in torque measuring method was proposed. The robot and its joint module and the torque measuring principle were introduced. Based on the two-order ripple model, strains on the flexspline were then analyzed. A new measuing method based on double compensations was proposed. This method cancels out the first order ripples by individual channels, and then cancels out the remain ripples by weighted stacking the signals. The relationship between output signal and torque was given, and a new gain-tuning method was presented. Finally, a simulation was conducted. The simulation proves that the proposed torque measuring method is correct and of high accuracy.

Abstract: The steering ratio of vehicle can be changed by attaching a angle, Changing the steering gear ratio can improve the safety in high-speed and comfort in low-speed and the vehicle steering stability. The paper introduces an active front steering system (AFS) based on harmonic drive, the composition and working principle of the system are analyzed, and the kinematic analysis of the system is researched, finally, the self-control mechanism and integrated control mechanism with other stability system are studied.

Abstract: In order to reduce the weight of harmonic drive (HD), the total volume of flexspline and circular spline was formulated and used as an objection function. Under the constraints including the condition on the strength of flexspline, the condition on averting the tooth top interference, the condition on the transmission ratio of HD and the geometrical constraint conditions of flexspline, a design optimization model with mixed discrete variables was established. For directly applying the optimal design solution of flexspline to manufacture, a manufacture-oriented method for dealing with mixed discrete design variables was used and the established model was solved by using an improved compound genetic algorithm. An optimal design example of flexspline was given and it shows that the proposed method is practical and effective.