ChiKit Au

Investigation of serpentine gait of a snake robot with a wireless camera

In this article, the serpentine gait of a snake robot with a camera at its head is simulated and the stability of the camera view is investigated. It is found that the camera view stability is low due to the large swinging amplitude of the snake robot head during locomotion. In order to improve the view stability, an optimization approach is proposed to modify the relative angle between the snake robot head and its body. Finally, a snake robot with wireless camera is implemented to verify the effectiveness of the proposed approach.

Investigation of electroless nickel plating on rapid prototyping material of acrylic resin

Purpose – This paper aims to investigate the layer of material deposited on a sample of acrylic resin by electroless nickel plating process. Acrylic resin is a popular material in rapid prototyping (RP) which uses the additive manufacturing technique to build prototypes for visual inspection, assembly, etc. Metallization of the RP materials can extend application envelop of RP techniques, as they can be used in decorative or functional applications. Design/methodology/approach – Unlike electroless nickel plating on a metal substrate, the plating process for an acrylic resin substrate is different, as there is no metal ion for the auto-catalytic electroless reaction. Pre-treatment processes are performed on an acrylic resin sample to initiate electroless nickel plating. The morphology, chemical composition and structure of the layer deposited on the sample are examined using scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. Findings – The investigation shows that a nickel ...

Space time of crowd evacuation from a room with two exits

This article discusses how the spatial structure is linked to the social behaviour by considering the crowd evacuation from a room with two exits. The individuals are represented by a group of particles. By considering the space time of the room, a room is partitioned into regions associated with the exits. The particles select their exits to leave the room based on their positions in these partitions and follow the path of least time. The change of environment such as the crowd size around the selected exit will be reflected on the partition and the particle may change its mind accordingly. Before a particle reaches an exit, it joins the crowd accumulated at that exit. This shows how the crowd accumulated around the exit influence the particle decision during the evacuation and their decisions affect the congestions around the exits.

Simulation of herding behaviour in panic evacuation from a room with two exits

Herding behaviour is typically shown in most panic crowd evacuation and it always causes disastrous outcomes due to the slow evacuation. Simulations of panic crowd evacuation from a room with two exits by using a crowd of particles are presented in this article. A panic crowd is characterised by higher moving speed and smaller inter-particle distance and the congestion at the exit is mainly caused by these factors. The particles move with an even high speed because of the congestion. This is a positive feedback mechanism and the herding behaviour arises at the exit with heavy congestion. Eventually, all the particles select the highly congested exit. This article also discusses how the space time of a particle is affected by the congestion and the herding behaviour is initiated.

Computation of the Shortest Path in a Bounded Domain With Free Form Boundary by Domain Partitioning

The shortest path computation is important in industrial automation, especially for robot and autonomous vehicle navigation. However, most of the computations concentrate on computing the shortest path between two points within a polygon. The common approach for handling a bounded domain with free form boundary is to convert the domain into a polygon by boundary approximation so that the conventional computing algorithms can be used. Such an approximation affects the accuracy of the path. This article presents an approach to compute the shortest path between two given points in a free form boundary domain without any boundary approximation. This is addressed geometrically by imaginably placing a source at one of the points which radiates the shortest paths to various points of the domain. Some shortest paths are deflected by the geometry of the boundary so that they are no longer straight lines. Based on the deflections of the shortest paths, the bounded domain is partitioned into a set of subdomains. A tree is then constructed to show the relationships among these subdomains. The shortest path between two points is obtained from this tree.

Computation of Offset Curves Using a Distance Function: Addressing a Key Challenge in Cutting Tool Path Generation

Tool path generation plays an important role in manufacturing. Tool paths should provide the cutter machine with the required geometry safely, efficiently, and economically, and ensure that the specified surface finish is achieved.

Patterns and pathways of packing circles into a square

Seeking an improbable, but globally optimum, state is useful in many scientific and engineering endeavours. To handle a larger data size, computational techniques are often employed. Yet, they are bound by the inherent combinatorial complexity. This paper employs the examples of packing a set of circles into a square to verify the existence of the pathways between the global optimisations based on the hypothesis that hopping from one known optimum to an unknown optimum in a global landscape is feasible. Twenty seven proven optimal circle packing configurations are investigated and eleven pathways are identified. These pathways lead to other optimal configurations which conform to the best known results. These pathways are beneficial to obtaining the optimum since it does not require going through the combinatorial many intermediate configuration before reaching the optimum.