Flexure coupling mechanisms for high performance robotics and automated processes

The Centre for Power Transmission and Motion Control (PTMC) has an exciting PhD opportunity to join its multidisciplinary team.

Many automated processes depend upon fast, repeatable and precisely controlled motion of a multibody mechanism. Conventional multibody systems, which are used in robotics and automated machinery, have joints which contain components that collide, roll and slide against each other. The associated interaction forces have an effect on the small-scale motion that limits achievable precision when the motion is controlled automatically using motors or other forms of actuation. This in turn impacts negatively on the quality and efficiency of various industrial processes, including the assembly and inspection of manufactured products.

The interaction forces within the joint can be eliminated by replacing traditional bearing with flexure couplings, which are compact deformable structures acting as pseudo-joints. This makes the small-scale motion behaviour more precise and predicable. Additional advantages are that a flexure coupling has no parts that rub together, are not subject to wear nor require lubrication. However, the flexure coupling behaviour has a complex nonlinear deflection response, introducing additional ways in which a mechanism can move and vibrate. These motions must be regulated through suitable actuation and control schemes to enable precise positioning.

Research is needed in order to allow an automated mechanism containing a flexure coupling to have precise, repeatable and fast motion. This will include how best to design a flexure coupling to enable a mechanism to have complete movement in three dimensions. An important consideration is how to apply actuation forces to a mechanism to achieve accurate control of motion, not only for precise positioning but also during rapid large-scale configuration changes, without causing unwanted oscillations or instabilities. Mathematical models will need to be developed for two purposes, the first to aid the design of the flexure coupling and mechanism for an optimized balance of speed, precision and range of motion, and secondly to develop algorithms and formulate control methodologies to regulate the actuation forces and thereby achieve precise control of motion.

The research for this PhD programme will engage in mathematical modelling, nonlinear dynamic analysis, control methodologies together with designing and building of a prototype joint/mechanism and testing. Theoretical concepts and design solutions will be taken through to practical implementation and experimental evaluation.

The PhD will be supervised by Dr Nicola Bailey ([Email Address Removed]) with support from Prof Patrick Keogh within the Centre of Power Transmission and Motion Control.