František Novotný

New Generation of Mobile Platform of Service Robot for Motion along Vertical Walls

The paper sums up results achieved during in the last few years of the development and research of service robots aiming their use for service applications on vertically oriented walls with predominantly smooth contact surfaces having minimal altitude unevenesses within the range ± 5 mm. Two robot generations are described step by step, and both of them use the same mechanical principle of the patented system of motion. The system uses the intermittent motion when positions of the robot legs and body alternate cyclically, and the appropriate gripping force of a holding-down system is realized by vacuum. As compared with the first version, the current one allows legs to move independent in part. In that way it is possible to compensate better variations of parallelism between a contact plane of the robot holding-down system and a vertical wall. Moreover, the robot is provided with a rotary unit making possible a rotation on the axis going through the robot center and being perpendicular to the contact plane, which guarantees a change in the robot orientation in the plane. As for drives, very compact rotary actuating mechanisms (servo drives) are used, having a high ratio of power parameters in relation to weight and dimensions, combined with a control based on an industrial PC.

Service Robot for Motion on the Vertical Oriented Walls

The paper submitted presents a new-generation mobile platform specially designed for the service robot destined for motion on vertical oriented walls, e.g. on glass façade systems of tower buildings. The platform has been developed goal-directly as a motive system allowing special technological extensions to be installed with a view to inspecting, assembling or washing. It uses a stepping principle alternating step by step the motion of legs and body. A holding system was created based on the vacuum principle with greater number of parallel suction cups associated with the smart vacuum technique. Component rotational motive units are fitted with servo-actuators with electro motors being controlled on the level of modular systems based on an embedded PC.

Chemical Reactions in a Soda-Lime Silicate Batch

Primary chemical reactions among the raw materials composing the batch give rise to various transitory intermediate products. Their physical properties influence the character of the glass melting process. The reaction pathway can be controlled by selecting the conditions, e.g. the grainsize composition of raw materials or the heating rate, which will influence the efficacy of the subsequent fining process. The present contribution describes practical technological properties of a couple of principal reaction pathways. A relationship between the practical monitoring of the actual glass melting process and the occurrence of peculiar chemical specimens is also mentioned.

Parallel Cooperation of Robots during Handling with Jumbo Glass Sheets

In the study, the mechanical behaviour of the robot, end effector – object – end effector, robot system is analyzed in terms of external forces affecting robots and their grippers as well as deformation forces influencing on the glass sheet through grippers provided that the robot kinematical structure and vacuum gripping head form an absolutely rigid system. The solution results are stress fields in the glass sheet, requirements for the robot path accuracy, and recommendations for solving special vacuum grippers for this type of robotic handling.

Special Gripping Elements for Handling with Flat Objects

The paper analyses possibilities to use new materials having a high degree of adhesion for designing vacuum gripping elements with a view to increase the radial capacity and at the same time to preserve the compressed air consumption or the vacuum level. Structural modification of the suction cup is presented with a bearing supporting plate having a material with an adhesion layer on the contact boundary and allowing the down-pressure to be regulated depending on mechanical properties of the object kept. In conclusion the results achieved are summarized illustrating a marked increase of the radial load capacity with regard to the defined vacuum level and the degree of shifting in the contact profile compared with the standard suction cups with a similar geometrical diameter in relation to the contact surface.

Problems of Loading Capacity of Suction Cups in the Radial Direction

The paper submits a computer analysis of a vacuum gripping element, a suction cup with the rigid supporting plate, loaded radially. Results of the computer simulation are used when designing new vacuum gripping elements which have a function of a controlled modification of the friction behaviour and adhesive properties of the element contact surface with a view to increase a carrying capacity in the radial direction keeping the vacuum levels used standardly. The designed vacuum elements will be used for technologically demanding processes during flat glass working having only limited energetic connection with their vicinity, and also for robotized handling objects of the plate design. A next field of application will include an induction of hold-down forces in climbing of service robots on glass facades of high-rise buildings [1, 2].

Aspects of a Safety Operation of Service Robots on Glass Walls

The paper focuses on problems of the safety operation of service robots on glass facades of high-rise buildings exposed to a local additional load during the robot motion and any subsequent service operation (e.g. cleaning, diagnostics, mounting). Owing to afraid of a possible glass cracking and a subsequent destruction, the authors pay attention to an analysis of the strength of façade glass sheets being in contact with the robot holding-down vacuum system as well as with the supporting steel construction. With a view of appraising a state of stress, a computer model was build up respecting the real composition of façade glass, material properties and contact edge conditions. The paper presents achieved results by means of graphic outputs, and in conclusion, it discusses them with aim to supply owners of service robots from a sphere of the building administration a number of details.

Adhesive Gripping Elements in a Construction of Gripping Heads

The paper describes possibilities to use industrially adhesive gripping elements in automatized handling processes especially for flat objects but also for objects slightly dissected according to height (e.g. sheets of glass, plastics, metals, plastic products etc.) which have dry, relatively clean, and smooth contact surfaces. It begins by analyzing results obtained in the field of designing combined vacuum-adhesive gripping elements, and the exclusively adhesive (passive) ones being suitable for technologically difficult handling conditions, e.g. in vacuum, as well. Furthermore, problems of the maximum carrying capacity of individual gripping elements being arranged parallel on a frame of a multi-element gripping head. A new concept of a compensation module of the gripping element position is presented as well, namely in relation to the head frame and to the handling object contact surface dissected according to height.

Materials Having a High Degree of Adhesion for Gripping Elements Designing

The paper analyses one of possibilities to use new materials based on polyurethane, polypropylene or silicone having highly adhesive contact surfaces for gripping elements designing. In concrete terms, it is a case of an alternative approach to the solution of designing standard multi-elements vacuum gripping heads with an active control system (vacuum level control) controlling gripping forces in processes of automatic handling flat objects of the plate type. The aim of this new design solution is to replace individual gripping elements (suction cups) by elements, the surfaces of which coming to the contact with the object handled are provided with adhesion materials. The system minimizing energy demands stemmed from this solution, namely in the way that it decreases or even eliminates the pressure air consumption when combined vacuum-adhesive or only adhesive gripping elements are used. Moreover, it is possible to use the adhesive gripping principle profitably in technological processes susceptible to the environment contamination with airflow when manufacturing new products with many functional layers. Besides a general analysis of problems, the paper presents outputs of laboratory tests. Also a computer model of the contact respecting rheological behaviour of the adhesive material basic matrix is given.