Fractional-Order Adaptive Integral Hierarchical Sliding Mode Control Method for High-Speed Linear Motion of Spherical Robot

Abstract

The development of the spherical robot to meet the requirements of high-speed and high-precision tasks is of great importance. In this study, a fractional-order adaptive integral hierarchical sliding mode controller (F-AIHSMC) is proposed. F-AIHSMC enables the spherical robot to have better controlled performance when facing unknown disturbances and system chattering, which can seriously affect the high-speed and high-precision motion of the spherical robot. We establish the standard dynamic model of the spherical robot for high-speed linear motion first, and then use the feedforward compensation method to compensate the controllable influencing factors in the motion process. According to the standard dynamic model, the integral term and fractional calculus methods are integrated into the hierarchical sliding mode controller, and the adaptive method is used to evaluate and compensate unknown disturbances in the high-speed motion process. In order to verify the efficiency of the proposed F-AIHSMC, we test its control effect using the BYQ-GS spherical robot. The experimental results demonstrate that, compared with the classical hierarchical sliding mode controller and the adaptive hierarchical sliding mode controller, the F-AIHSMC has obvious advantages in response speed, convergence speed, stability and robustness when being applied to the control of high-speed linear motion of spherical robot. Moreover, the advantages of its control performance are more highlighted with the increase of the speed of the spherical robot. INDEX TERMS Adaptive control, fractional calculus, hierarchical sliding mode control, high-speed motion control, spherical robot.

Research on self-reconfiguration strategy of modular spherical robot

“…It combines the design concept of spherical robot and modular robot to solve the problem of poor motion ability of traditional modular robot. As shown in Figure 1, it is an evolutionary version of the robot designed in Ma et al, 34 there are six retractable and rotatable connectors distributed on the spherical module. Three of them are active connectors (connector 1, 3, 5) and other three connectors are passive connectors (connector 2, 4, 6), and connector 1 and connector 2 can swing up and down.…”

Direction and Trajectory Tracking Control for Nonholonomic Spherical Robot by Combining Sliding Mode Controller and Model Prediction Controller

“…The long axis motor is employed to control the velocity while and the short axis motor is employed to control the direction [1]. As a result, the spherical robot may perform omnidirectional motion on a plane by adjusting the output torque of the two motors [4].…”

“…The spherical robot is a novel kind of mobile robot which can be used in a range of fields such as environmental detection, search and rescue, security patrols and entertainment. Compared with other mobile robots like wheeled robots and legged robots, spherical robots have several advantages [1]- [4]. For example, because of its spherical rolling mechanism, the spherical robot can have flexible omnidirectional mobility and minimal frictional energy consumption.…”

“…Over the last few years, a series of works have been made on the control of the spherical robot. The majority of study concentrates on the spherical robot's velocity control [1], [2], [4], [9]- [12].Several studies, for instance, develop a velocity controller based on feedback control, such as a PI-type fuzzy logic controller [10]. Linear quadratic regulator (LQR) and sliding mode controller (SMC) are also utilized in the design of velocity controllers [1], [12].…”

“…Linear quadratic regulator (LQR) and sliding mode controller (SMC) are also utilized in the design of velocity controllers [1], [12]. Some studies develop a velocity controller by combining integral approach, adaptive law, and SMC [4]. Adaptive velocity controllers for spherical robots are also available by predicting the uncertainty [2], [8], [9].…”