Hybrid extendable linear actuators: design and applications

There are many types of different actuators in the field of robotics. For applications where a linear displacement is required, a linear extendable actuator would be the method of choice. The hybrid class of extendable actuators possesses unique features making it suitable for many applications where the soft and rigid types fall short. However, there has not been a clear designation and classification of extendable linear hybrid actuators in the literature. This paper addresses this matter and provides the first overview of the hybrid class of extendable actuators. The paper performs a categorization and characterization of this class of extendable linear actuators based on their method of operation as well as the inherent unique features separating them from the rest. The paper contains five sections, and three sub-sections pertaining to the different categories of Hybrid actuators, and their applications. New research in this field continues to add features to this class of actuators through improvements and added capabilities

Face-recognition based security robot incorporating omnidirectional vision

Security robots are gathering an increasing interest as a supplement to current security systems due to their advantages of continuous effective surveillance and low cost of operation. Current security robots, however, have their own limitations which is preventing them from being used on a large scale in real world environment. The main objective of this research is to develop a security robot that can efficiently be used in real-world environments by overcoming the limitations of most security robots, to guard properties and humans from intruders that may compromise the safety of the premises or its inhabitants. The robot developed in this research uses motion detection by image subtraction. When motion is perceived a face detection programme using the Viola Jones method coupled with skin-color-content detection is used to find out whether the motion was caused by a person or otherwise. If a face of a person or more is found, then the face recognition stage is utilized to verify the familiarity of the person(s) detected by using three different face recognition algorithms (Fisher faces, Eigen faces and LBPH (Local Binary Pattern Histogram)) to ensure maximum identification under different pose, facial expression and lighting conditions. If the person(s) is determined to be a stranger, the robot would raise an alarm and navigate towards the subject to authenticate him/her through a password entry check

Design and analysis of a vertically suspended soft manipulator

Soft robotic manipulators have many traits and are increasing being used in many different fields. The design and stress analysis of a manipulator is a starting point for its fabrication and subsequent use in the corresponding fields of application. In this paper, the design of a continuum manipulator and stress analysis of its critical parts are presented. The illustration is divided into three levels to facilitate the conception of the full assembly. The design illustrates the constituent parts and their associations, and the stress analysis indicates the areas bearing the most stress as well as the maximum expected displacement in the part’s body. This study provides a guideline for researchers to implement their design concepts, towards achieving the full outcome of their research

Design, fabrication, and performance analysis of a vertically suspended soft manipulator

Soft continuum manipulators are comprised of flexible materials in a serpentine shape. Such manipulators can be controlled mechanically through tendons or pneumatic muscles. Continuum manipulators utilizing tendons are traditionally formed in a thick cross section, which presents limitations in achieving a high bending range as well as difficulties for storage and transportation. This study introduces a continuum manipulator comprised of two thin plastic bands and driven by a tendon to provide a bending action. The manipulator’s thin body form enables it to be rolled up for storage and transportation. Experimental results on different section lengths show the possibility of achieving a horizontal displacement of up to 34% of the bending-segment’s length, and a full closed-loop curvature for most segments. However, the results also indicated an elongation of the tip paths owing to gravity. These results, in addition to the manipulator’s flexibility and light weight features, confirm its suitability for applications in space and underwater environments

Characteristics of a tendon driven soft gate for canal flow regulation

Surface irrigation in farming is controlled by canal gates that regulate the flow of water. Canal gates have traditionally been fabricated from rigid material and require construction work to implement them. This results in a relatively high cost, and the inability to easily relocate them if necessary. In this work a soft gate is proposed that uses flexible material to regulate the flow of water through the canal. The utilization of a flexible arm reduces the cost of the gate, facilitates its installation and relocation as well as being less vulnerable to blockage due to its flexible nature. The results of the experiments indicate the possibility of regulating the flow of water through canals widths of up to 55% of the flexible arm's length