Slalom: A Gecko-Inspired Robot with Lateral Body Undulation

Introduction: A World of Agile Locomotion

Drawing inspiration from nature’s creatures has long been a large part of robotics design and development. Some of these inspirations come from the agile locomotion of sprawling animals such as salamanders and geckos. These inspirations led to the development of walking, climbing, and swimming robots with climbing robots receiving the most attention in investigation of such animals.

What makes sprawling animals special is that they posses a remarkable feature: they have a flexible spine that enables them to bend and twist their bodies while utilizing their limbs for movement. Hence, this feature is the key to their agile locomotion, enabling them to navigate various terrains with ease.

The Two Streams of Robot Development for Sprawling Posture Robots

There are two main approaches when it comes to developing sprawling posture robots: one inspired by salamanders and the other by geckos.

For the robots inspired by the salamanders, the aim is to derive inspiration from the bendable segmented spine of salamanders which enables them to make smooth transitions between walking, swimming, and climbing.

As for the robots inspired by geckos, the aim is to derive inspiration from the foot structure and adhesion mechanism. These robots are particularly useful for climbing smooth surfaces. Research in this area mainly focuses on the foot structure and the adhesion material and not so much on the crucial role of lateral body undulation – the side-to-side motion utilized by animals such as geckos for enhanced stability, energy efficiency, and propulsion during climbing or crawling.

Slalom Robot to Bridge the Gap Utilizing Lateral Body Undulation

The importance of lateral body undulation (the side-to-side motion) for gecko-inspired robots has been largely overlooked by researchers. Thus, the Slalom robot proposes an optimal bendable body design to achieve the benefits outlined above; i.e., stability and energy-efficiency during climbing. Unlike previous gecko-inspired robots with fixed bodies, Slalom utilizes bendable body with three degrees of freedom (DOFs), closely mimicking the lateral movements of geckos.

The Science Behind Slalom

In-depth observations of gecko locomotion were conducted using high-speed camera recordings and motion tracking analysis to inform the design and development of Slalom. These observations enabled the careful study of gecko movements and in turn the creation of the bendable body for Slalom with just the right number of joints to represent the gecko’s agility.

Slalom consists of four limbs, each with four joints, and a bendable body with three joints. A central pattern generator (CPG)-based neural control system is used for coordination between these joints, and hence, precise control over Slalom’s movements during locomotion.

The efficiency of Slalom in terms of body movement were validated through real robot experiments on various inclined surfaces. It was shown that, when compared to robots with fixed bodies, Slalom achieves a significantly reduced energy consumption due to its lateral body undulation. Therefore, by leveraging the dynamics of its bendable body and coordinated movements, Slalom achieved impressive climbing performance while conserving energy.

Agility in Sprawling Posture Robots Paving the Way for Future Climbing Robotics

Slalom demonstrated significant energy efficiency due to its body design, and this marks a significant advancement in sprawling posture robot development. Combining the best features of both salamander and gecko-inspired designs has led to new possibilities for energy-efficient locomotion on inclined surfaces. But the journey does not stop here – with further refinements, these robots could be practically deployed in various industries ranging from search and rescue to exploration and beyond.