  Snakes and their bio-inspired robot counterparts have demonstrated locomotion
on a wide range of terrains. However, dynamic vertical climbing is one
locomotion strategy that has received little attention in the existing snake
robotics literature. We demonstrate a new scansorial gait and robot inspired by
the locomotion of the Pacific Lamprey. This new gait allows a robot to steer
while climbing on flat, near-vertical surfaces. A reduced-order model is
developed and used to explore the relationship between body actuation and
vertical and lateral motions of the robot. Trident, the new wall climbing
lamprey-inspired robot, demonstrates dynamic climbing on flat vertical surfaces
with a peak net vertical stride displacement of 4.1 cm per step. Actuating at
1.3 Hz, Trident attains a vertical climbing speed of 4.8 cm/s (0.09 Bl/s) at
specific resistance of 8.3. Trident can also traverse laterally at 9 cm/s (0.17
Bl/s). Moreover, Trident is able to make 14\% longer strides than the Pacific
Lamprey when climbing vertically. The computational and experimental results
demonstrate that a lamprey-inspired climbing gait coupled with appropriate
attachment is a useful climbing strategy for snake robots climbing near
vertical surfaces with limited push points.
