This paper presents the Vega robot, which is a small, low cost, potentially disposable ground robot designed for nuclear decommissioning. Vega has been developed specifically to support characterization and inspection operations, such as 2D and 3D mapping, radiation scans and sample retrieval. The design and construction methodology that was followed to develop the robot is described and its capabilities detailed. Vega was designed to provide flexibility, both in software and hardware, is controlled via tele‐operation, although it can be extended to semi and full autonomy, and can be used in either tethered or untethered configurations. A version of the tethered robot was designed for extreme radiation tolerance, utilizing relay electronics and removing active electronic systems. Vega can be outfitted with a multitude of sensors and actuators, including gamma spectrometers, alpha/beta radiation sensors, LiDARs and robotic arms. To demonstrate its flexibility, a 5 degree‐of‐freedom manipulator has been successfully integrated onto Vega, facilitating deployments where handling is required. To assess the tolerance of Vega to the levels of ionizing radiation that may be found in decommissioning environments, its individual components were irradiated, allowing estimates to be made of the length of time Vega would be able to continue to operate in nuclear environments. Vega has been successfully deployed in an active environment at the Dounreay nuclear site in the UK, deployed in nonactive environments at the Atomic Weapons Establishment, and demonstrated to many other organizations in the UK nuclear industry including Sellafield Ltd, with the goal of moving to active deployments in the future.

Ground robotic vehicles are often deployed to inspect areas where radioactive floor contamination is a prominent risk. However, the accuracy of detection could be adversely affected by enhanced radiation signal through self-contamination of the robot occurring over the course of the inspection. In this work, it was hypothesised that a six-legged robot could offer advantages over the more conventional ground robotic devices such as wheeled and tracked rovers. To investigate this, experimental contamination testing and computational Monte Carlo simulation techniques (GEANT4) were employed to understand how radioactive contamination pick-up on three different robotic vehicles would affect their detection accuracy. Two robotic vehicles were selected for comparison with the hexapod robot based on their type of locomotion; a wheeled rover and a tracked rover. With the aid of a non-toxic fluorescent tracer dust, the contamination received by the all three vehicles when traversing a contaminated area was initially compared through physical inspection using high definition cameras. The parametric results from these tests where used in the computational study carried out in GEANT4. A cadmium zinc telluride detector was simulated at heights ranging from 10 to 50 cm above each contaminated vehicle, as if it were mounted on a plinth. Assuming a uniform activity of 60 Bq cm(-2) on all contaminated surfaces, the results suggested that due to the hexapod's small ground-contacting surface area and geometry, radiation detection rates using an uncollimated detector are likely to be overestimated by between only 0.07%-0.12%, compared with 3.95%-8.43% and 1.75%-14.53% for the wheeled and tracked robot alternatives, respectively.

In this paper we propose and demonstrate a novel void characterisation algorithm which is able to distinguish between internal and external voids that are present in point clouds of both manifold and non-manifold objects and 3D scenes. We demonstrate the capabilities of our algorithm using several point clouds representing both scenes and objects. Our algorithm is shown in both a descriptive overview format as well as pseudocode. We also compare a variety of different void detection algorithms and then present a novel refinement to the best performing of these algorithms. Our refinement allows for voids in point clouds to be detected more efficiently, with fewer false positives and with over an order of magnitude improvement in terms of run time. We show our run time performance and compare it to results obtained using alternative algorithms, when tested using popular single board computers. This comparison is important as our work is intended for online robotics applications, where hardware is typically of low computational power. The target application for this work is 3D scene reconstruction to aid in the decommissioning of nuclear facilities.

Nuclear facilities often require continuous monitoring to ensure there is no contamination of radioactive materials that might lead to safety or environmental issues. The current approach to radiological monitoring is to use human operators, which is both time consuming and cost inefficient. As with many repetitive, routine tasks, there are considerable opportunities for the process to be improved using autonomous robotic systems.

Mobile robots are playing a significant role in Higher Education science and engineering teaching, as they offer a flexible platform to explore and teach a wide-range of topics such as mechanics, electronics and software. Unfortunately the widespread adoption is limited by their high cost and the complexity of user interfaces and programming tools. To overcome these issues, a new affordable, adaptable and easy-to-use robotic platform is proposed. Mona is a low-cost, open-source and open-hardware mobile robot, which has been developed to be compatible with a number of standard programming environments. The robot has been successfully used for both education and research at The University of Manchester, UK.

Mobile robots are playing a significant role in multi and swarm robotic research studies. The high cost of commercial mobile robots is a significant challenge that limits the number of swarm based research studies that implement real robotic platforms. On the other hand, the observed results from simulated robots using simulation software are not representative of results that would be obtained using real robots. There are therefore considerable benefits in the development of an affordable open-source and flexible platform that allows students and researchers to implement experiments using real robot systems. Mona is an open-source and open-hardware mobile robot that has been developed at the University of Manchester for this purpose. Mona provides a robotic solution that can be programmed and operated using a user-friendly interface, Arduino, with relative ease. The low cost of the platform means that it is feasible for a large number of these robots to be used in swarm robotic scenarios. This work was supported by EPSRC (Project No. EP/P01366X/1 and EP/P018505/1). Introduction Swarm robotics is a relatively new concept in multi-robotic collective behaviour research studies that has emerged from studies using robots with limited abilities that are assigned to following simple tasks [1]. Swarm robotic scenarios are mostly inspired form social behaviour of insects and other animals and there have been many successful implementations of swarm behaviours which have been directly inspired from nature (e.g. honeybees [2], cockroaches [3], ants [4], and birds [5]). As highlighted in [6], one of the main criteria of swarm robotics is operating experiments with a “large number of robots”, typically at least 10 20. Recently, the number of robots used in swarm robotics has increased dramatically with swarm sizes of up to 1000 robots being reported [7]. To implement such large sizes of swarms with commercial robots can therefore be very costly. To tackle this issue, affordable open-source and open-hardware robotic platforms are playing an important role in research and education. Several mobile robots have been developed and successfully deployed in swarm robotic research studies, such as Khepera [8], Alice [9], Jasmine [10], E-puck [11], Colias [12], SwarmBot [13], Kilobot [14], and S-bot [15]. In these studies bio-inspired collective behaviour has been imitated, however, despite this work only a limited number of low-cost, open-source, and open-hardware mobile robots are available for use in swarm robotic research studies. For example, ’Colias’ is an open-source, low-cost mobile robot that was developed for application to swarm scenarios. A large group of Colias robots played the role of young honeybees role to mimic BEECLUST aggregation [16]. Colias has also been utilised to study bio-inspired vision mechanism [17] and artificial pheromone communication system [18]. Recently, Mona has been developed as a low-cost mobile robot for research and education purposes. The first version of Mona was utilised in a study on the feasibility of creating a Perpetual Robot Swarm system, where the robot was able to recharge itself whilst in motion [19]. The Mona robot has been developed, in collaboration with a commercial partner, as a low-cost platform (£100) for robotic education and swarm/collaborative research. It has been successfully used for teaching on an undergraduate unit and MSc projects in University of Manchester. The rest of this paper provides briefly on its design and capabilities. Mona Robot Mona (Fig. 1) uses a circular PCB board with the diameter of 8 cm accommodates its modules including main processor, motors and drivers, infra-red proximity sensors, power management, Figure 1: (a) Mona robot, (b) ROS module (breakout board for Teensy 3.2 and WiFi), and (c) an expansion board for the off-the-shelf modules: Raspberry Pi Zero, RF transceiver, and XBee. and 3.7 V Li-Po battery. Mona is a modular robot hence any module that uses the serial communication standards (i.e. RS232, I2C, and SPI) can be easily attached to the robot. Due to open-source criterion of the Mona, Arduino [20] that is one of the most successful opensource platforms was used to program the Mona. The important reasons to use Arduino were: i) it is relatively easy platform in comparison to other open-source platforms, ii) the rich set of online forums and available libraries with free access, and iii) variety of Arduino compatible programming environments especially for young age students. An AVR 8-bit microcontroller (Atmega-328, with 32 KB in-system self-programmable flash memory and 2 KB internal SRAM) was utilised as the main processor. The main clock source is an external 16 MHz crystal oscillator. Two micro DC gearhead motors (with a high gear ratio of 280:1) and two wheels with diameter of 28 mm move Mona with a maximum speed of 10 cm/s. The rotational speed for each motor is controlled individually using a pulse-width modulation (PWM) technique. Each motor is controlled separately with a macroscopic model of the utilized motors [21]. In addition, the utilised motors have magnetic encoders attached to the back side of the motors. Each encoder generates two pulses per rev (before gear), which provides enough precision in terms of wheels’ displacement. The output of the encoders can be used as an input to a proportional-integral-derivative (PID) controller for closed-loop motion control. The main sensory system which is used in Mona is the short-range infra-red (IR) proximity sensors. Five sensors in front half of the robot, which were located in 35◦ angular distance estimate the distance of an obstacle by translating the received reflected IR to an analogue voltage [22]. Mona also monitors its battery level using an ADC (analog-to-digital converter) channel of the main processor by sampling its battery level by a voltage divider including two resistors. To study on possibility of controlling Mona using ROS (Robot Operating System), a breakout board has been made that supports a Teensy 3.2 module and a WiFi module, as shown in Fig. 1(b). The board was attached on top of Mona and communicates via UART (universal asynchronous receiver-transmitter). In this configuration, an ID was assigned to each Mona and the base-station (ROS server) receives sensory readings from each Mona and also sends commands to Mona’s motors and LEDs via WiFi module. In addition, a breakout board as shown in Fig. 1(c) has been developed which supports: i) Raspberry Pi Zero, ii) XBee module, and iii) NRF24L01 RF transceiver. The board is mounted on top of the main platform and is able to communicate with the main platform using RS232 serial port. Mona has been developed based on an AVR RISC micro-controller (ATMega328P). The architecture of the robot allows connecting the robot to Arduino-based platforms via a USB cable. However, it is possible to use any programming language which was developed for AVR micro-controllers including C, C++, Java, Pascal, Basic, and Assembly. Mona’s design library and codes are available at [23].