LEGO-type Structural Design and Binocular Visual Interface

乐高是一种起源于北欧的玩具积木。乐高积木游戏与实际结构设计有一些相似之处。由于工业标准和经济/建筑效率的原因，这种结构由有限集合的元素组成。我们称它们为“乐高式结构”。脚手架结构是乐高式结构的典型，超大空间结构也可以是乐高式结构。我们将乐高式结构设计分为三种模式：系统设计、连接设计和元素设计。本研究考虑的是乐高型桁架结构的连接设计模式。采用同种乐高积木，加载条件假定给定。组装这些块，我们试图找到最优的配置。表示结构构型的设计变量是离散的；因此，设计优化是一个离散优化问题。神经网络由相互连接的神经元组成。一些离散优化问题可以在最小化自身能量的人工神经网络上进行编程和求解。离散变量用神经元数值表示。神经元状态的二进制值为1或0。为了摆脱局部最小值，我们引入了玻尔兹曼机，它是一种结合模拟退火算法的概率神经网络模型。数值算例验证了所提方法的适用性。为了使最优结构可视化，我们引入了一个使用头戴式显示器的虚拟现实系统。尽管具有双目立体视觉，但复杂桁架结构的构型识别并不容易。

LEGO is a toy block of North Europe origin. LEGO blocks play has some analogy with practical structure designs. Such structures are composed of the elements from finite sets on account of the industrial standard and for reasons of economical/building efficiencies. We call them by the name of 'LEGO-type structures.' Scaffolding structures are typical examples of the LEGO-type structure, and very large space structures may be also.We classify LEGO-type structural designs into three modes : system design, connection design, and elements design. Considered in this study is the connection design mode for LEGO-type truss structures. LEGO-type blocks of the same kind are used, and the loading conditions are assumed to be given. Assembling the blocks we try to find the optimal configuration. The design variables to represent the structural configuration are discrete ; so that the design optimization is a discrete optimization problem.Neural networks consist of mutually interconnected neurons. Some discrete optimization problems can be programmed and solved on artificial neural networks that minimize their own energy. The discrete variables are represented numerically by neurons. The neuron state takes binary values of one or zero. To escape from the local minimum we introduce the Boltzmann machine, which is a probabilistic neural networks model combined with the simulated annealing algorithm.Numerical examples are provided to verify the applicability of the proposed method. In order to visualize the optimal structure, we introduce a virtual reality system using a head mounted display. Despite binocular stereopsis, it is not easy to recognize the configuration of a complicated truss structure.