Spherical Robots for Special Purposes: A Review on Current Possibilities

Abstract

The review discusses the possibilities of different driving mechanisms and sensors of spherical robots, and a special kind of mobile robots is introduced and discussed. The sensors discussed can expand robots’ sensing capabilities which are typically very limited. Most spherical robots have holonomic characteristics and protect the inner environment using a shell. Today, there are a diversity of driving mechanisms. Therefore, this article provides a review of all of them and identifies their basic properties. Accordingly, many spherical robots have only inner sensors for moving, balancing, driving, etc. However, a few of them are also equipped with sensors that can measure environmental properties. Therefore, in this paper, we propose the possibility of using such sensors as cameras, LiDARs, thermocouples, and gas sensors, which can be used for special purposes underground, for example, in mines, underground tunnels, or road tunnels. After combining all components are combined, it is possible to design a special type of spherical robot designed for underground exploration, such as accidents in mines or road tunnels.

Tiny Spherical Robot with a Magnetic Field-Based Interference Detection and Prevention Framework

“…e difference field due to a ferromagnet will point near the object's position when the sensor is situated at the precise middle point between the two magnets, according to equation (9). Although the above derivations are based on the premise that the item is indefinitely huge and has infinite permeability, the result holds for finite objects.…”

“…However, after conducting practical tests with the infrared sensor, the scientists discovered that the performance had deteriorated owing to scratching between the shell and the ground, which produces signal diffraction and refraction. e transmission of electromagnetic-based sensing is unaffected by the plastic shell, making it more promising [9]. One of the most important aspects of autonomous navigation for mobile robots is real-time obstacle detection and avoidance.…”

Special spherical mobile robot for planetary surface exploration: A review

“…In 2021, Bahar et al 7 reviewed the research progress of amphibious spherical robots since 2015, and divided their driving modes into three categories: leg drive, combined drive, and linear drive. In 2022, Bujnák et al 8 divided the driving principle of spherical robots into three categories: direct drive, gravity drive, and angular momentum drive, summarized the corresponding dynamic empirical formula, and proposed a spherical robot concept that can be used for underground gas exploration. In contrast, this article attempts to review all relevant published reports in the field of spherical robots related to extraterrestrial exploration, which can be used as examples of robot design, modeling, planning, control and application in extreme service environments.…”

A tripodal wheeled mobile robot driven by a liquid metal motor

“…At present, this simple wheel-driving form has been applied to single-wheeled robots. 2 Gallium-based liquid metal (LM) is a kind of liquid alloy material that is similar to mercury but has extremely low toxicity. Via adjustment of the applied external physical field, this controllable liquid metal droplet (LMD) provides new solutions and opportunities for many disciplines and research directions, [3][4][5] especially in the fields of flexible electronics, [6][7][8] microfluidics, [9][10][11][12] soft sensors, 13-15 actuators, [16][17][18][19] micro-robotics, [20][21][22][23][24] and biomaterials.…”