Continuum Delta Robot: a Novel Translational Parallel Robot with Continuum Joints

Researches on continuum robots thrive due to many advantages such as design compactness and motion dexterity. Among the recent advances, it is well noted the proposal of Parallel Continuum Robot (PCR) whose legs are made from elastic rods. The legs undergo deformations along their entire lengths and sophisticated mechanics is used to describe their shapes and the kinematics. Following a different approach, this paper proposes to design parallel robots with continuum joints. The continuum joints would assume constant curvature bending and hence produce relatively simple kinematics. With the bending ranges achievable beyond 90°, a parallel robot with continuum joints, instead of universal or spherical joints, can realize larger workspace. As a particular demonstrative example, a Continuum Delta Robot (CDR) is proposed. Each of the CDR's legs consists of two coupled continuum joints which inherently realize translational movements of the end effector. The design concept, kinematics, system description and experimental characterizations are presented. From the presented Continuum Delta Robot, more parallel robots with continuum joints can be proposed and new design methodology can be developed.