A new hybrid machine design for a 6 DOF industrial robot arm

Industrial robot arms are an essential part of automated manufacturing and are used due to the facts that they are highly repeatable; can be calibrated to be sufficiently accurate and they eliminate human error. They automate tasks such as component assembly; welding; light machining; spray painting; etc. The industrial serial robot arm architecture is by far the most ubiquitous in modern day manufacturing, as their technology is highly refined in its current state; the machine architecture provides extreme dexterity and it has a large useful workspace. This architecture however does have some problems, first the machine mass distribution is not efficient as that mass is spread throughout the arm, and the arm itself contains significant inertia. The primary reason for this lies in the location of the motors and gearboxes. A secondary effect of this mass distribution is that it leads to inaccuracy and dynamic vibration problems. This journal paper focuses on the design of a novel robotic arm design having a hybrid nature. It is labelled as hybrid due to the fact that its architecture departs from both the classic definitions of Serial Kinematics Machines (SKMs) and Parallel Kinematics Machines (PKMs). The primary goal of its design was to merge the advantages of the 2 architectures, i.e. a large workspace to footprint ratio which is found in serial robots, and the low inertia of a parallel robot resulting in increased speed. Serial and parallel robots are complementary, and as such, these design goals cannot coexist in a single robot architecture. To realise the objectives mentioned, 2 unique mechanisms had to be created so that a full complement of 6 DOF (degrees of freedom), could be attained. Comparatively, once the design goals are met, this hybrid mechanism would be better than any industrial robot used in industry.