Maciej Zawidzki, Ph.D., Eng.

Department of Intelligent Technologies (ZTI)
Division of Intelligent Systems (ZeSI)
position: assistant professor
telephone: (+48) 22 826 12 81 ext.: 221
room: 449
e-mail: mzawidzk
personal site: http://www.zawidzki.com/

Doctoral thesis
2010-09Application of computational intelligence to engineering design problems in architecture -firmitatis, utilitatis, venustatis-  (RUKJ)
supervisor -- Tateyama Kazuyoshi, RUKJ
1332 
Recent publications
1.Zawidzki M., Deployable Pipe-Z, Acta Astronautica, ISSN: 0094-5765, DOI: 10.1016/j.actaastro.2016.05.023, Vol.127, pp.20-30, 2016
Abstract:

This paper presents a concept of deployable Pipe-Z (dPZ): a modular structural system which takes advantage of the robustness of rigid-panel mechanism and allows to create free-form links which are also reconfigurable and deployable. The concept presented can be applied for building habitats and infrastructures for human exploration of oceans and outer space. dPZ structures can adapt to changing requirements e.g. mission objectives, crew condition and technological developments. Furthermore, such lightweight and adaptable structural concept can assist in sustainable exploration development. After brief introduction, the concept of Pipe-Z (PZ) is presented. Next, the reconfigurability of PZ is explained and illustrated with continuous and collision-free transition from a PZ forming a Trefoil knot to a Figure-eight knot. The following sections introduce, explain and illustrate the folding mechanism of a single foldable Pipe-Z module (fPZM) and entire dPZ structure. The latter is illustrated with asynchronous (delayed) unfolding of a relatively complex Unknot. Several applications of PZ are suggested, namely for underwater and deep-space and surface habitats, for permanent, but in particular, temporary or emergency passages. As an example, a scenario of a failure of one of the modules of the International Space Station is presented where a rigid structure of 40 fPZMs bypasses the “dead link”. A low-fidelity prototype of a 6-module octagonal dPZ is presented; several folding schemes including concentric toric rings are demonstrated. Practical issues of pressurization and packing are briefly discussed.

Keywords:

Ocean and space outpost; Banana-split; Deployable structure; Rigid-panel folding; Free-form

Affiliations:
Zawidzki M.-other affiliation
2.Zawidzki M., Optimization of Multi-branch Truss-Z based on Evolution Strategy, Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2016.07.015, Vol.100, pp.113-125, 2016
Abstract:

This paper concerns multi-branch Truss-Z networks (MTZ). A possible scenario for creating a “multi-branch bridge” linking 6 terminals of pedestrian and cycling communication is presented. This process is formulated as a constrained minimization problem. New, biology-inspired nomenclature for MTZ and encoding for MTZ are introduced. Several operations for MTZs are introduced and illustrated. The functionality of these operations is illustrated with transformation from a random MTZ to a “proper” 6-branch MTZ network. A population-based heuristic experiment is presented to demonstrate that the introduced operators allow us to create any desirable MTZ. A cost function for the considered scenario is introduced. The genetic operations are interpreted and visualized. A number of feasible MTZ layouts produced by an evolution strategy-based algorithm are presented. One of these layouts is used for creation of the spatial 6-terminal MTZ, which is also visualized.

Keywords:

Extremely modular system, Modular ramp system, Multi-branch network, Modular structure encoding, Evolution strategy, Discrete layout optimization

Affiliations:
Zawidzki M.-other affiliation
3.Zawidzki M., Automated geometrical evaluation of a plaza (town square), Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2016.01.018, Vol.96, pp.58-69, 2016
Abstract:

This paper presents a method for an automated geometrical evaluation (AGE) intended as a design support tool for urban design of a plaza (P). AGE is based on three normalized properties derived from a plan of P, namely: smallness, enclosure, and regularity. 19 worldwide plazas have been evaluated by 20 respondents in, what is called here, human subjective evaluation (HSE). A brief analysis of HSE including the identification of redundant categories is presented. Two P evaluation methods based on all four (S,C,E,R) and selected three (S,E,R) properties are discussed. Good agreement of AGE based on S,E, and R (NPSER) with HSE is shown. P quality rating (excellent, good, fair) based on NPSER is introduced. Exceptional cases are briefly discussed

Keywords:

Urban composition; Public square; Plaza; Layout evaluation; Design support tool; Normalized accumulated quality

Affiliations:
Zawidzki M.-other affiliation
4.Zawidzki M., Dynamic shading of a building envelope based on rotating polarized film system controlled by one-dimensional cellular automata in regular tessellations (triangular, square and hexagonal), Advanced Engineering Informatics, ISSN: 1474-0346, DOI: 10.1016/j.aei.2014.09.008, Vol.29, No.1, pp.87-100, 2015
Abstract:

The original prototype of the cellular automaton (CA) shading system (CASS) for building facades was based on rectangular array of cells and used liquid crystal technology. This paper introduces polarized film shading system (PFSS) – an alternative approach based on opto-mechanical modules whose opacity is a function of the rotation of polarized film elements. PFSS in regular tessellations: triangular, square and hexagonal are discussed. Simulations for each type of tessellation are presented and visualized. Visual attractiveness of emergent CA patterns manifested by ‘‘particles’’ and ‘‘solitons’’ is discussed.

Keywords:

Adaptive architecture, Organic architecture, Building envelope, CA shading

Affiliations:
Zawidzki M.-other affiliation
5.Zawidzki M., Retrofitting of pedestrian overpass by Truss-Z modular systems using graph-theory approach, Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2014.11.004, Vol.81, pp.41-49, 2015
Abstract:

Installing pedestrian ramps is a common improvement towards a barrier-free environment. This paper introduces a graph-theoretical method of retrofitting of a single-branch Truss-Z (TZ) ramp in a constrained environment. The results produced by this exhaustive search method are usually ideal and better than those produced previously with meta-heuristic methods. A large case study of linking two sections of the Hongo Campus of Tokyo University using an overpass in an extremely constrained environment is presented. TZ modules with 1:12 (8.3%) slope are used, which is allowable in most countries for ramps for self-powered wheelchairs. The results presented here are highly satisfactory both in terms of structural optimization and aesthetics. Visualizations of the TZ ramp system, composed of 124 units, are presented.

Keywords:

Truss-Z, Modular lightweight system, Organic design, Discrete structural optimization, Retrofitting, Pedestrian ramp, Breadth-first search, Wavefront algorithm, Unknown graph exploration

Affiliations:
Zawidzki M.-other affiliation
6.Zawidzki M., Chraibi M., Nishinari K., Crowd-Z: The user-friendly framework for crowd simulation on an architectural floor plan, Pattern Recognition Letters, ISSN: 0167-8655, DOI: 10.1016/j.patrec.2013.10.025, Vol.44, pp.88-97, 2014
Abstract:

This paper introduces Crowd-Z (CZ): a framework that provides a user-friendly platform where architects can perform simple crowd simulations on floor plans. A simple but robust and flexible agent-based system is used for modeling of the crowd dynamics. Such simulations can be performed at any stage of design – from rough sketches to the final blueprints. CZ allows acquiring the layouts for the simulations in a number of ways: freehand sketches, importing already prepared images and appropriating preprocessed images from commercially available Computer Aided Design programs. These three methods are illustrated with practical examples, followed by a number of simulations compared with the literature or other commercially available programs.

Keywords:

Pedestrian dynamics; Agent based modeling; Design support; Digitized floor plan

Affiliations:
Zawidzki M.-other affiliation
Chraibi M.-Jülich Supercomputing Centre (DE)
Nishinari K.-The University of Tokyo (JP)
7.Zawidzki M., Nishinari K., Application of evolutionary algorithms for optimum layout of Truss-Z linkage in an environment with obstacle, Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2013.04.022, Vol.65, pp.43-59, 2013
Abstract:

Truss-Z (TZ) is a concept of a modular system for creating free-form links and ramp networks. It is intended as a universal transportation system for cyclists and pedestrians, especially ones with strollers or carts, and in particular – by persons on wheelchairs, the elders, etc. In other words, TZ is for people who have difficulties using regular stairs or escalators. With only two types of modules, TZ can be designed for nearly any situation and therefore is particularity suited for retrofitting to improve the mobility, comfort and safety of the users. This paper presents an application of evolution strategy (ES) and genetic algorithm (GA) for optimization of the planar layout of a TZ linkage connecting two terminals in a given environment. The elements of the environment, called obstacles, constrain the possible locations of the TZ modules. Criteria of this multi-objective optimization are: the number of modules to be the smallest, which can be regarded as quantitative economical optimization, and the condition that none of the modules collides with any other objects, which can be regarded as qualitative satisfaction of the geometrical constraints. Since TZ is modular, the optimization of its layout is discrete and therefore has combinatorial characteristic. Encoding of a planar TZ path, selection method, objective (cost) function and genetic operations are introduced. A number of trials have been performed; the results generated by ES and GA are compared and evaluated against backtracking-based algorithm and random search. The convergence of solutions is discussed and interpreted. A visualization of a realistic implementation of the best solution is presented. Further evaluation of the method on three other representative layouts is presented and the results are briefly discussed.

Keywords:

Truss-Z, Modular skeletal system, Organic design, Meta-heuristic discrete optimization, Retrofitting, Pedestrian ramp

Affiliations:
Zawidzki M.-other affiliation
Nishinari K.-The University of Tokyo (JP)
8.Zawidzki M., Bator M., Application of Evolutionary Algorithm for Optimization of the Sequence of Initial Conditions for the Cellular Automaton-Based Shading, Journal of Cellular Automata, ISSN: 1557-5969, Vol.7, pp.363-384, 2013
Abstract:

This paper presents an application of evolutionary algorithm (EA) for multi-objective optimization of the sequence of initial conditions (SIC) for a cellular automaton (CA) used for a potential implementation in the field of architecture. In the proposed application, a modular shading system for building facade is driven by a two color, one dimensional, range 2 CA rule {3818817080,2,2}. The SIC optimization criteria are: visual attractiveness, gradual and intuitive transition from one density level to another and even distribution of the pattern over the entire array. The ideal solutions for 10 square arrays of 7×7, 8×8,..., 16×16 cells are found by an exhaustive search method – the backtracking. The encoding of SICs using the order-based representation is introduced. A cost function evaluating both monotonicity of the average density transition, and the distribution of shading pattern is introduced. For a 100×100 cell array EA is implemented with three setups: without crossover but with intensive mutation, with crossover and without mutation, and with both crossover and mutation. Two types of crossover operations are used: uniform (UX) and one-point (OPX). A number of experiments with various combinations of parameters were performed. The results are compared and the recommended strategy is briefly discussed. The best result was produced by EA with OPX and mutation rate 0.4.

Keywords:

Modular shading system, initial conditions, multi-objective optimization, discrete optimization, backtracking, order-based representation, evolutionary algorithm

Affiliations:
Zawidzki M.-other affiliation
Bator M.-Warsaw University of Life Sciences (PL)
9.Zawidzki M., Nishinari K., Shading for Building Facade with Two-Color One-Dimension Range-Two Cellular Automata on A Square Grid, Journal of Cellular Automata, ISSN: 1557-5969, Vol.8, pp.147-163, 2013
Abstract:

A practical application of cellular automata (CA) in the field of Architecture is presented, where one-dimensional CA on a square grid drives a modular shading system of a building facade. Examples of three classes: general, semi-totalistic and totalistic of two-color one-dimension range-two automata are analyzed for potential practical use. The problem of desired change in the opacity of the shading array as a function of the sequence of initial conditions (SIC) is discussed. The ideal SlCs for selected CAs on 12 x 12 cell arrays found by backtracking algorithm are presented. The influenee of the type of boundary conditions (BC) is discussed and a special type of a fixed BC is introduced. The robustness of the system under two types of permanent failure is analyzed - the single cell failure, and deactivation of a single column of cells.

Keywords:

Adaptive architecture, modular shading system, fixed boundary conditions, Robustness, failure

Affiliations:
Zawidzki M.-other affiliation
Nishinari K.-The University of Tokyo (JP)
10.Zawidzki M., Nishinari K., Modular Truss-Z system for self-supporting skeletal free-form pedestrian networks, Advances in Engineering Software, ISSN: 0965-9978, DOI: 10.1016/j.advengsoft.2011.12.012, Vol.47, No.1, pp.147-159, 2012
Abstract:

This paper presents the concept of Truss-Z (TZ) – a skeletal system for pedestrian traffic which is composed of only two modules and allows the creation of complex three-dimensional self-supporting networks connecting any number of terminals in a given environment. TZ is intended as a universal, feasible and practical system for newly designed situations and most importantly, for retrofitting, especially where the use of heavy equipment is impossible or uneconomic.
TZ allows automated creation of optimal spatial links where the only required inputs are the coordinates of the terminals and the geometry of the obstacles. As an example a six-terminal network created with a backtracking based algorithm is shown. An alternative method of aligning consecutive modules to a given 3D path is also presented.
A preliminary static analysis of the TZ module is carried out – the topological qualities of rigidity and independence are demonstrated.

Keywords:

Truss-Z, Modular skeletal system, Self-supporting structure, Organic design, Discrete structural optimization, Retrofit pedestrian link, Pathfinding with backtracking

Affiliations:
Zawidzki M.-other affiliation
Nishinari K.-The University of Tokyo (JP)
11.Zawidzki M., Tateyama K., Nishikawa I., The constraints satisfaction problem approach in the design of an architectural functional layout, ENGINEERING OPTIMIZATION, ISSN: 0305-215X, DOI: 10.1080/0305215X.2010.527005, pp.1-24, 2011
Abstract:

A design support system with a new strategy for finding the optimal functional configurations of rooms for architectural layouts is presented. A set of configurations satisfying given constraints is generated and ranked according to multiple objectives. The method can be applied to problems in architectural practice, urban or graphic design—wherever allocation of related geometrical elements of known shape is optimized. Although the methodology is shown using simplified examples—a single story residential building with two apartments each having two rooms—the results resemble realistic functional layouts. One example of a practical size problem of a layout of three apartments with a total of 20 rooms is demonstrated, where the generated solution can be used as a base for a realistic architectural blueprint. The discretization of design space is discussed, followed by application of a backtrack search algorithm used for generating a set of potentially ‘good’ room configurations. Next the solutions are classified by a machine learning method (FFN) as ‘proper’ or ‘improper’ according to the internal communication criteria. Examples of interactive ranking of the ‘proper’ configurations according to multiple criteria and choosing ‘the best’ ones are presented. The proposed framework is general and universal—the criteria, parameters and weights can be individually defined by a user and the search algorithm can be adjusted to a specific problem.

Keywords:

Architecture, design support, architectural layout optimization, multi-objective, discrete Optimization, CSP

Affiliations:
Zawidzki M.-other affiliation
Tateyama K.-Ritsumeikan University (JP)
Nishikawa I.-Ritsumeikan University (JP)

Conference papers
1.Zawidzki M., Jankowski Ł., Szklarski J., Structural optimization of a five-unit single-branch Truss-Z modular structure, SMART 2017, 8th Conference on Smart Structures and Materials, 2017-06-05/06-08, Madrid (ES), pp.525-535, 2017
Abstract:

Truss-Z (TZ) is an Extremely Modular System (EMS). Such systems allow for creation of structurally sound free-form structures, are comprised of as few types of modules as possible, and are not constrained by a regular tessellation of space. Their objective is to create spatial structures in given environments connecting given terminals without self-intersections and obstacle-intersections. In an EMS, the assembly, reconfiguration and deployment difficulty is moved towards the module, which is relatively complex and whose assembly is not intuitive. As a result, an EMS requires intensive computation for assembling its desired free-form geometrical configuration, while its advantage is the economization of construction and reconfiguration by extreme modularization and mass prefabrication. TZ is a skeletal modular system for creating free-form pedestrian ramps and ramp networks among any number of terminals in space. TZ structures are composed of four variations of a single basic module (Truss-Z module, TZM) subjected to affine transformations (mirror reflection and rotation). The previous research on TZ focused on global discrete optimization of the spatial configuration of modules. This contribution reports on the first attempts at structural optimization of the TZM for a single-branch TZ. Namely, the internal topology of a TZM and sizing of its elements are subject to optimization. An important challenge is due the fact that TZM is to be universal, i.e., it must be designed for the worst case scenario. There are four variations of each module, and due to symmetries there are thus 4^4 = 256 unique 5-unit configurations. The structural performance of all of them needs to be evaluated in terms of a typical structural criterion (the maximum von Mises effective stress), and used for structural optimization at the level of a single TZM.

Keywords:

Extremely Modular System, Truss-Z, Structural optimization, Effective stress

Affiliations:
Zawidzki M.-IPPT PAN
Jankowski Ł.-IPPT PAN
Szklarski J.-IPPT PAN
2.Zawidzki M., Jankowski Ł., Multicriterial optimization of geometrical and structural properties of the basic module of a single-branch Truss-Z structure, WCSMO12, 12th World Congress of Structural and Multidisciplinary Optimisation, 2017-06-05/06-09, Braunschweig (DE), pp.1-9, 2017
Abstract:

Truss-Z (TZ) is an Extremely Modular System (EMS). Such systems allow for creation of structurally sound free-form structures, are comprised of as few types of modules as possible, and are not constrained by a regular tessellation of space. Their objective is to create spatial structures in given environments connecting given terminals without self-intersections and obstacle-intersections. In an EMS, the assembly, reconfiguration and deployment difficulty is moved towards the module, which is relatively complex and whose assembly is not intuitive. As a result, an EMS requires intensive computation for assembling its desired free-form geometrical configuration, while its advantage is the economization of construction and reconfiguration by extreme modularization and mass prefabrication.
TZ is a skeletal modular system for creating free-form pedestrian ramps and ramp networks among any number of terminals in space. TZ structures are composed of four variations of a single basic module (Truss-Z module, TZM) subjected to affine transformations (mirror reflection and rotation). The previous research on TZ focused on global discrete optimization of the spatial configuration of modules. This contribution is the first attempt at structural optimization of the TZM for a single-branch TZ. The result is a multicriterial optimization, where the Pareto front provides the means to strike the optimal balance between geometric and structural assessment criteria.

Keywords:

multicriterial optimization, Truss-Z, effective stress, modular systems

Affiliations:
Zawidzki M.-IPPT PAN
Jankowski Ł.-IPPT PAN