This paper aims to discuss the requirements of safe and smooth trajectory planning of transporter mobile robots to perform non-prehensile object manipulation task. In non-prehensile approach, the robot and the object must keep their grasp-less contact during manipulation task. To this end, dynamic grasp concept is employed for a box manipulation task and corresponding conditions are obtained and are represented as a bound on robot acceleration. A trajectory optimization problem is defined for general motion where dynamic grasp conditions are regarded as constraint on acceleration. The optimal trajectory planning for linear, circular and curve motions are discussed. Optimization problems for linear and circular trajectories were analytically solved by previous studies and here we focused with curve trajectory where Genetic Algorithm is employed as a solver tool. Motion simulations showed that the resulted trajectories satisfy the acceleration constraint as well as velocity boundary condition that is needed to accomplish non-prehensile box manipulation task. تفاصيل المقالة

در این مقاله برای مدل‌سازی فضای حالت عمومی مبدل چند‌سطحی سری متصل به شبکه، روشی جامع پیشنهاد شده است. در اینورترهای چند‌سطحی به دلیل غیر‌خطی بودن رفتار آنها، برای تضمین پایداری سیستم در حوزه کاری وسیع استفاده از کنترل کننده غیر‌خطی اجتناب ناپذیر است. برای همین منظور مدل‌سازی فضای حالت جهت طراحی این نوع کنترل کننده ها لازم است. مدل پیشنهاد شده برای حالت کلی مبدل با تعداد n پل ارائه شده است. برای راستی آزمایی مدل فضای حالت به دست آمده، یک نمونه آزمایشگاهی از مبدل چند‌سطحی با دوپل طراحی و ساخته شده و نتایج مربوط به شبیه‌سازی مدل فضای حالت به دست آمده با نتایج شبیه‌سازی مبدل متصل به شبکه و نتایج عملی مقایسه شده است. مقایسه نتایج نشان‌دهنده درستی عملکرد مدل است. همچنین شبیه‌سازی های مربوطه توسط نرم افزار تخصصی EMTDC/PSCAD انجام یافته است. تفاصيل المقالة

Object manipulation techniques in robotics can be categorized in two major groups including manipulation with and without grasp. The aim of this paper is to develop an object manipulation method where in addition to being grasp-less, the manipulation task is done in a passive approach. In this method, linear and angular positions of the object are changed and its manipulation path is controlled. The manipulation path is a screwed track with constant radius and incline. As there is no actuator and active controller in the mechanism, the system requires a kind of mechanical intelligence to navigate the object from initial to goal configuration. This intelligence is achieved by geometry of the object and dynamical and kinematical characteristics if the object and the track. A general set up for the components of the system is considered to satisfy the required conditions. Then after kinematical analysis, detailed dimensions and geometry of the mechanism is obtained. M.SC-ADAMS is exploited to simulate the proposed mechanism تفاصيل المقالة