Mobility Solutions for Robot Inspection Arm

Award winning product designer, Industrial Design Consultancy (IDC) has achieved a new level of machine mobility and casing design; bringing multi-axis manoeuvrability to a robot CMM (Coordinate Measuring Machine). This latest industrial project required the development of mobility casing solutions for the Metris Robot CMM Arm (RCA); an innovative new measurement system designed for 3D laser scanning inspections on the production line.

Metrology company Metris wanted a design which would enhance their Robot CMM Arm, whilst maintaining maximum manoeuvrability with small housings for difficult measurement locations. In achieving this, IDC was challenged to pack nearly 3500 parts into a housing with a system that provided 7 degrees of freedom. With so many parts moving in different directions, IDC’s engineers had to work closely with the Metris design engineers to develop mechanical and casing solutions which were of minimal size. The main difficulty to overcome when reducing the size and weight was in providing sufficient clearance for all the moving parts, while avoiding friction problems. Metris also introduced new safety features that had to be incorporated in the design.

IDC’s MD Stephen Knowles explains, “The RCA is a highly technical piece of equipment. To develop a fully functional cover system within the short timescale available required us to work hand-in-hand with the Metris engineers. The result was that our integrated design and engineering team became an extension of Metris’ project group creating a machine with visual appeal and allowing the development to proceed much faster with fewer design iterations.”

IDC successfully achieved the size and manoeuvrability that Metris was looking for and the resulting RCA is now capable of accessing inner cavity locations of products, such as vehicle body shells. Such unlimited accessibility is a major leap forward compared to traditional CMMs that have difficulty reaching enclosed part surfaces.

The RCA system itself combines a highly accurate internal 7‑axis articulated arm with an external skeleton driven by electric motors. This unique process creates a measuring robot that drives a Metris MMD laser scanner along the programmed motion path. With Metris’ premium encoder technology and stiff carbon fibre axes, RCA intrinsically provides absolute measurement accuracy within an inspection volume of 4.2 metre diameter.