A Compact Magnetic Field-Based Obstacle Detection and Avoidance System for Miniature Spherical Robots

Abstract

Due to their efficient locomotion and natural tolerance to hazardous environments, spherical robots have wide applications in security surveillance, exploration of unknown territory and emergency response. Numerous studies have been conducted on the driving mechanism, motion planning and trajectory tracking methods of spherical robots, yet very limited studies have been conducted regarding the obstacle avoidance capability of spherical robots. Most of the existing spherical robots rely on the “hit and run” technique, which has been argued to be a reasonable strategy because spherical robots have an inherent ability to recover from collisions. Without protruding components, they will not become stuck and can simply roll back after running into bstacles. However, for small scale spherical robots that contain sensitive surveillance sensors and cannot afford to utilize heavy protective shells, the absence of obstacle avoidance solutions would leave the robot at the mercy of potentially dangerous obstacles. In this paper, a compact magnetic field-based obstacle detection and avoidance system has been developed for miniature spherical robots. It utilizes a passive magnetic field so that the system is both compact and power efficient. The proposed system can detect not only the presence, but also the approaching direction of a ferromagnetic obstacle, therefore, an intelligent avoidance behavior can be generated by adapting the trajectory tracking method with the detection information. Design optimization is conducted to enhance the obstacle detection performance and detailed avoidance strategies are devised. Experimental results are also presented for validation purposes.

The Kinematics and Dynamics Motion Analysis of a Spherical Robot

“…The difference is that in a spherical robot, the steering of angular velocity affects the angular velocity of the robot's side roll. Most of spherical robots adopt the pendulum or inverted pendulum mechanism, and from this design kinematics and dynamics are derived [4] Path planning and trajectory tracking control are derived from dynamics into velocity control [9], sliding mode controller [22] [23], position control [2] [27], motion control [28], and trajectory tracking control [31] [32] [33] [35]. The path planning design of a spherical robot on current research are Norsahperi et al 2015 [4] investigated the possibility of bouncing mechanism in a sphere robot by using Particle Swarm Optimization (PSO) technique.…”

“…Wu et al 2017, [32] introduced a passive magnetic field to detect obstacle during spherical robot deployment. The obstacle detection is used by avoidance behavior to generate the trajectory tracking method.…”

Engineering Knowledge Graph for Keyword Discovery in Patent Search

“…In this section, we demonstrate the proposed method via a case study of the patent search for spherical rolling robots (SRRs) from the USPTO patent database. SRRs are spherical shape robots that can propel themselves to roll around on the ground (Bicchi et al, 1997;Kim et al, 2016), and have been developed for defence and surveillance applications (Wu et al, 2017) and as toys and other consumer applications. An of example SRR is presented in Figure 4.…”

Smartphones Magnetic Sensors within Physics Lab

“…The sensors of magnetic field based on the Hall effect are the most used magnetic sensors and allow us to know the linear position, angular position, speed, rotation, current [56][57][58][59] and the three components of the field magnetic [60][61][62][63][64].…”