2 research outputs found
A snake robot with mixed gaits capability
Snake robots are mostly designed based on single
mode of locomotion. However, single mode gait most of the
time fails to work effectively when they are required to work in
different cluttered environment with different measures of
complexity. As a solution, mixed mode locomotion is proposed
in this paper by synchronizing serpentine gait for
unconstricted workspace and wriggler gait for narrow space
environment through development of a simple gait transition
algorithm. This study includes the investigation on kinematics
analysis followed by dynamics analysis while considering
related structural constraints for both gaits. This approach
utilized speed of the serpentine gait for open area operation
and exploits narrow space access capability of the wriggler
gait. Hence, this approach in such a way increases motion
flexibility in view of the fact that the snake robot is capable of
changing its mode of locomotion according to the working
environment
Control of snake robots with switching constraints: trajectory tracking with moving obstacle
We propose control of a snake robot that can switch lifting parts dynamically according to kinematics. Snakes lift parts of their body and dynamically switch lifting parts during locomotion: e.g. sinus-lifting and sidewinding motions. These characteristic types of snake locomotion are used for rapid and efficient movement across a sandy surface. However, optimal motion of a robot would not necessarily be the same as that of a real snake as the features of a robot’s body are different from those of a real snake. We derived a mathematical model and designed a controller for the three-dimensional motion of a snake robot on a two-dimensional plane. Our aim was to accomplish effective locomotion by selecting parts of the body to be lifted and parts to remain in contact with the ground. We derived the kinematic model with switching constraints by introducing a discrete mode number. Next, we proposed a control strategy for trajectory tracking with switching constraints to decrease cost function, and to satisfy the conditions of static stability. In this paper, we introduced a cost function related to avoidance of the singularity and the moving obstacle. Simulations and experiments demonstrated the effectiveness of the proposed controller and switching constraints