Purpose: The purpose of this paper is to propose a new propeller-type climbing robot called EJBot for climbing various types of structures that include significant obstacles, besides inspection of industrial vessels made of various materials, including non-ferromagnetic material. The inspection includes capturing images for important spots and measuring the wall thickness. Design/methodology/approach: The design mainly consists of two coaxial upturned propellers mounted on a mobile robot with four standard wheels. A new hybrid actuation system that consists of propeller thrust forces and standard wheel torques is considered as the adhesion system for this climbing robot. This system generates the required adhesion force to support the robot on the climbed surfaces. Dynamic simulation using ADAMS is performed and ensures the success of this idea. Findings: Experimental tests to check the EJBot’s capabilities of climbing different surfaces, such as smooth, rough, flat and cylindrical surfaces like the real vessel, are successfully carried out. In addition, the robot stops accurately on the climbed surface at any desired location for inspection purposes, and it overcomes significant obstacles up to 40 mm. Practical implications: This proposed climbing robot is needed for petrochemical and liquid gas vessels, where a regular inspection of the welds and the wall thickness is required. The interaction between the human and these vessels is dangerous and not healthy due to the harmful environment inside these vessels. Originality/value: This robot utilizes propeller thrusts and wheel torques simultaneously to generate adhesion and traction forces. Therefore, a versatile robot able to climb different kinds of structures is obtained.

This paper presents a new kind of climbing robots called EJBot, which has not been restricted to climb certain surface materials or terrains. EJBot is inspired by propeller-based aviation systems, however, its adhesion principle is opposite to flight concept. Thanks to the hybrid actuation system embedded in this robot which gives a good and stable adhesion. This hybrid system consists of propeller thrust forces and wheel torques actuated simultaneously to generate the proper adhesion force. It is similar to a car climbing a ramp, it needs both weight of the car and the wheels' torques. Without these torques, the car will roll down. Consequently, the thrust forces of the propellers increase the traction force capacity, then the wheels' role arises to generate the convenient torques for stopping the robot or navigating it on the structures. The feasibility of this adhesion concept is verified by the first and second modules of EJBot as presented in the simulation and practical results.

The dual-reciprocating drill (DRD) is a low-mass alternative to traditional drilling techniques biologically inspired by the wood wasp ovipositor, which is used to drill into wood in order to lay its eggs. The DRD reciprocates two halves lined with backwards-facing teeth, enabling it to generate traction forces that reduce the required overhead penetration force. While previous research has focused on experimental testing of the drill’s operational and design parameters, numerical simulation techniques are being developed to allow the rapid testing of multiple designs, complementing and informing experimental testing campaigns. The latest DRD design iteration integrated a novel internal actuation mechanism and demonstrated the benefits of adding controlled lateral movements. This paper presents an exploration of how bit morphology affects drilling performance and a preliminary study of discrete element method (DEM) simulations for modelling DRD interactions in regolith. These have shown how regolith grain size and microscopic behaviour significantly affects the performance of different drill designs, and demonstrated how customisable drills can exploit the properties of various substrates. Two system prototypes are also being developed for the DRD’s third generation, each utilising novel actuation and sampling mechanisms. A final drill design will then be deployed from a planetary rover and perform the first DRD drilling and sampling operation.

Most robotic applications demand lightweight and high-speed manipulators for considerably reducing the consumed power and achieving high production rates. The two ways for seeking such high-speed arms are; applying advanced control algorithms and/or performing an extensive optimization of the arm structure itself. Therefore, the topology optimization technique is proposed here for obtaining an optimal robot arm design from both structure and control viewpoints. Results of some researches, that have been previously accomplished by size and shape optimization, were encouraging enough to extend and propose this optimization approach. The method of moving asymptotes (MMA) as an optimization algorithm, the finite element analysis (FEA) by ANSYS, and the time-optimal control method are integrated to gain an optimum design capable of attaining the minimum traveling time. The proposed methodology focuses on performing different comparisons between the proposed optimum topological designs and their initial designs for different robot arms’ sizes and materials. It also distinguishes between the proposed optimum design and the previously achieved one by size optimization under the same operational conditions. Therefore, the significance of the proposed technique is emphasized. It shows that the traveling time is reduced by 44.8%, while the previous work only achieved 23.5%. In addition, the mass is reduced to nearly half of its initial value, taking into account the air damping as the real case in all terrestrial applications. Communicated by John McPhee.

This paper is proposing and designing a novel propeller-type climbing robot for exploring the interiors of industrial vessels and enables a human outside it to implement required regular inspection tasks efficiently. There are two main adhesion systems in the literature: magnetic and air suction systems. The magnetic system climbs surfaces made of ferromagnetic materials only, while air suction system can handle neither irregular surfaces due to possible seal damage nor cylindrical surfaces. Opposite to previous climbing robots, the proposed robot here can climb and navigate vessels made from different materials besides handling possible irregular or cylindrical surfaces. Its main task is visual inspection of welds and any critical spots inside these vessels. The novelty of this robot comes from utilizing a hybrid actuation system consists of upturned propellers fixed on mobile robot with motorized wheels. The pressure generated from the upturned propellers increases the friction force between the wheels of the mobile robot and the wall. The wheels' motors generate the required torque either to fix the robot at any position or to move it to any place. Since the motion of the robot comes mainly from the motorized wheel, the stability of the system during navigation is guaranteed. Simulation and control results of the designed robot using ADAMS and Matlab softwares prove the success and feasibility of the robot concept.