The robot inspired by nature

Louise Davis

Commonly recognised for its bulging eyes and triangular head, the praying mantis is often portrayed as a motionless predatory insect. Here, Graham Mackrell, managing director of  gear manufacturer Harmonic Drive UK, explains how the insect is inspiring design engineers when creating the next generation of robots.
The Robotics Innovation Centre at the German Research Centre for artificial intelligence (DFKI) and the University of Bremen have collaborated on a project that amplifies some of the well-known qualities associated with the praying mantis. The Mantis is a multi-legged robot, designed with six extremities that offer high mobility and flexibility, making it agile — just like its real-life counterpart.
In recent years, the rising demand for robots to carry out more complex tasks also increased the intelligence requirements of these systems. The scope of environments and sectors that robots are now being used in is wide ranging and the Mantis has been created with this in mind.
Designed as an autonomous system that can adjust quickly and operate effectively in extreme conditions and against rough terrain, the Mantis can be used on earth or in space. In fact, the robot’s creators made it so that it complied with the learning intelligent motions for kinematically complex legged robots for exploration in space (LIMES) framework. In the future, the device will be deployed to take soil samples and assemble infrastructure in space.
When picturing the praying mantis, many of us imagine its trademark upright posture, enlarged forelegs and crossed forearms as if in prayer. The Mantis has been created, however, with two dominating postures. The first is a manipulation posture, which reflects the traditional mantis stance and is used to grip objects. The other is a locomotion posture.
The locomotion posture requires each of the robot’s extremities to allow the device to move. To drive the locomotion unit, the robot has been equipped with our Harmonic Drive CPL Component Sets. Comprising of three components, a Circular Spline, Flexspline and Wave Generator, design engineers have maximum freedom to integrate these components into their application.
The reason Harmonic Drive’s offering was used for this particular project, was because of its components’ compact and low weight design. The large shaft can be used to feed through supply cables, shafts and cables for other drive systems in the device.
These features are important for the operation of the Mantis as the virtual system of the robot can use various criteria, such as energy consumption and speed, to generate and optimise different locomotion behaviours. Providing the behaviours offer stable and high-quality operation, the robot will store the behaviour in its library and activate it when appropriate.
The Mantis is an innovative example of how nature is inspiring the answers to our modern-day engineering problems. While many of us would never think to consider the insects, we share our planet with as having the answer, it’ll be interesting to see how many more robot developments take a similar approach.