Closed-loop Control of a Nonprehensile Manipulation System Inspired by the Pizza-Peel Mechanism

A nonprehensile manipulation system consisting of a dexterous plate (e.g., a peel) which is intended to induce a rotating movement on a disk (e.g., a pizza) is studied. A dynamic model based on the Euler-Lagrange equations is first derived. Then, a controllability analysis of this model is carried out, which shows some intrinsic limitations of the proposed system. Later, a closed-loop control strategy is proposed to induce the desired rotating speed in the disk, while maintaining the position of both the disk and the plate as close to zero as possible. A stability analysis is performed to show the boundedness of all the states, the oscillatory response of all of them, and the maximum amplitude of these oscillations. A numerical simulation is employed to verify the proposed controller and the predicted behavior found in the stability analysis

Novi mehanizam za pasivno-dinamičnu manipulaciju objektom duž zakrivljenog puta

Object manipulation is a basic task in robotics and automation. Active manipulation by grasp is conventional approach in object manipulation. However, in many cases, grasp-less manipulation can be beneficial in terms of cost, minimalism and extension of workspace. On the other hand passive mechanisms are advantageous from the energy saving viewpoint. In this paper we combine these ideas to develop a dynamic passive object manipulation mechanism to achieve manipulation in more than one dimension and simultaneously change position and orientation of the object. In developed mechanism the manipulation platform is a simple inclined surface. The object is composed of two wheels with different radiuses and an axle connecting the wheels to each other. The object moves passively along a circular path on the platform. Kinematic equations of the motion are devised, dynamic analyses are performed and no-slippage conditions are extracted. Modelling in CATIA and simulations in MSC.ADAMS are performed and experimental set up is built to verify the analysis.Manipulacija objektom je osnovni zadatak u robotici i automatici.Aktivna manipulacija hvatom predstavlja konvencionalan prostup manipulaciji objektom. Ipak, u mnogim slučajevima, manipulacija objektom bez hvata može biti korisna u smislu troškova, minimalizma i proširenja radnom prostora.S druge strane, pasivni mehanizmi posjeduju prednosti iz perspektive uštede energije. U ovom radu mi kombiniramo ove ideje kako bismo razvili dinamično-pasivni mehanizam za manipulaciju objektom u svrhu postizanja manipulacije u više od jedne dimenzije i simultano mijenjali poziciju i orijentaciju objekta. U razvijenom mehanizmu platforma za manipulaciju sastoji se od jednostavne nagnute plohe. Objekt se sastoji od dvaju kotača različitih radijusa i jedne osi koja spaja kotače. Objekt se kreće pasivno duž zakrivljenog puta na platformi.Postaljene su jednadžbe kinematike gibanja, te je analizirana dinamika, dok je klizanje zanemareno. U svrhu verifikacije analize izrađen je model eksperimentalnog postava u CATIA-i te su provedene simulacije korištenjem MSC.ADAMS alata