Bosch Rexroth gives some legs to Mantis walking robot

Posted on 25 Jun 2013 by Tim Brown
The “Mantis” hexapod robot is aimed at applications both in the film industry and other sectors, such as unmanned subsea exploration

Mantis, the world’s biggest operational all terrain hexapod robot, which was unveiled earlier this year, has been kitted with 18 Rexroth valves and a pump to allow its legs to move.

The nine foot (2.7 metres) tall robot, which resembles a giant insect and can be driven remotely or piloted from the machine’s cockpit, took four years to develop.

Rexroth 4WREE6 valves provide the integral function of controlling the hydraulic cylinders that operate the Mantis’ six legs. Each leg features three independent closed loop axes, one at the knee and two at the hip, with feedback provided by sensors installed on the outside of the leg.

Mantis is the brainchild of chief designer Matt Denton, managing director of Micromagic Systems, who first decided upon the concept and created the computer controls that give the machine its high functionality. These include the ability to move omnidirectionally (forwards/backwards, crab left/right, turn left/right), climb over uneven ground and raise and lower on command.

Speaking about the machine’s development Matt said: “I’d been making smaller hexapod robots for a number of years for use in the film and TV industries as well as for private collectors. I felt that if I could scale up the machine to the point where it could carry a person that, as well as demonstrating what is possible with current technologies and British engineering, there could be further applications both in the film industry and other sectors, such as unmanned subsea exploration, and work in environments that are sensitive to terrain damage.

“I was aware of Rexroth valves from their use in special effects on films I’d worked on in the past. Having contacted Bosch Rexroth I was put in touch with Nigel Hart who, as well as specifying the Rexroth 4WREE6 valves, provided assistance and advice on the hydraulic design of circuits, safety considerations, reducing the reservoir size and cooling. What impressed me most about the Bosch Rexroth valves, and proved essential to the functionality of the machine, was the smooth and accurate control they provide.”

In addition to the 18 Rexroth 4WREE6 valves, Rexroth provided an A10VO63DFR pump. Typically used in mobile machinery the A10VO63DFR supplies the robot’s hydraulic power. Fitted with load sensing the pump ensures that only the right flow and pressure is delivered reducing power consumption.

Nigel Hart, sector manager for Marine and Offshore at Bosch Rexroth UK said: “Mantis is a fantastic demonstration of what can be achieved with today’s technology. It is also indicative of the significant changes that have happened throughout the industry over the past ten to fifteen years. Now even the most simple of components come with intelligence that allows it to perform a variety of functions and adapt to a number of applications.”