Swing control for a three-link brachiation robot based on sliding-mode control on irregularly distributed bars

Abstract

Abstract. The bionic-gibbon robot is a popular bionic robot. The bionic-gibbon robot can imitate a gibbon in completing brachiation motion between branches. With nonlinear and underactuated properties, the robot has important research value. This paper designs a type of bionic-gibbon robot with three links and two grippers. To simplify the controller, a plane control model is proposed, and its dynamic model is established. The control strategy in this paper divides the brachiation motion into several processes: adjust posture, open the gripper, the swing process and close the gripper. Based on sliding-mode control (SMC), the control method for the swing process is designed. The target position of the brachiation motion is set as the origin of the sliding-mode surface. In a finite time, the robot will reach the target position along the approach rate we adopt. In this way, the robot can complete the desired brachiation motion only by setting the position parameters of the target bar. We perform some simulations in ROS-Gazebo. The simulation results show that the bionic-gibbon robot can complete continuous brachiation motion on irregularly distributed bars. The sliding-mode control and the three-link structure significantly improve the robustness and swing efficiency of the bionic-gibbon robot.

Design of Transverse Brachiation Robot and Motion Control System for Locomotion between Ledges at Different Elevations

“…In this phase, the robot maintains the posture achieved in the previous phase while swinging the tail link repeatedly until the swing amplitude is sufficient to initiate brachiation. Note that a swing-up phase is commonly used in underactuated mechanical systems, such as brachiation robots [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ] or acrobots [ 28 , 29 , 30 ]. Among the numerous control methods proposed for robot swing motion control [ 31 , 32 , 33 , 34 , 35 ], we adopted the energy-based method proposed by Spong [ 32 ] to generate the torque by which to drive the actuated link (tail), such that the direction of the torque vector is the same as the direction of the underactuated link (body and arms).…”

“…In the current study, we developed a robot that performs transverse overhand brachiation tasks in navigating routes that include multiple ledges at different elevations. The movements of existing transverse brachiation robots with an anterior orientation perpendicular to the direction of movement can be categorized as follows: (1) Grasped object orientation perpendicular to the direction of movement and parallel to the ground [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ]; (2) Grasped object orientation perpendicular to the direction of movement and perpendicular to the ground [ 23 ]; (3) Grasped object orientation parallel to the direction of movement and parallel to the ground [ 1 , 13 , 24 , 25 , 26 ].…”

“…Most existing brachiation robots designed for horizontal locomotion use the aforementioned assumptions on underactuated joints for the sake of simplicity. Very few studies have applied brachiation to the problem of moving from one ledge at a given elevation to another ledge at a different elevation, despite the fact that such actions are common in most practical situations [ 22 , 27 ]. Brachiation performance depends largely on the complexity of contact dynamics between the gripper and ledge.…”

Multi-Locomotion Design and Implementation of Transverse Ledge Brachiation Robot Inspired by Sport Climbing

“…Humans and apes are both primates, so brachiation robots modeled on humans and apes are similar [ 14 ]. However, the target handholds of ape-inspired robots are round ladder rungs [ 15 , 16 ] or cables [ 17 , 18 ], whereas TLB robots move transversely at 90° to ledges [ 2 ]. Conventional brachiation robots mostly focus on efficiently accumulating energy during the swinging process and planning joint trajectories to facilitate continuous brachiation between spaced rungs [ 19 , 20 , 21 ].…”

Jumping Motion Based on Momentum Optimization Control and Differential Dynamic Programming for a Multilocomotion Robot

“…[ 1 ] MLR is a novel, biologically inspired primate‐like robot. Previously, several forms of locomotion, such as ladder climbing, [ 2 ] biped walking, [ 3 ] and brachiation [ 4 ] have been developed. In addition to these, jumping motion is an essential motion mode for the robot.…”