This project explored how an autonomous robot cart can support professional painters by reducing physical strain while remaining intuitive and predictable to use. Through user-centred research, field studies, prototyping, and iterative testing, I designed a shared-control interaction system that prioritised simple tactile controls and transparent robot behaviour over complex autonomy. The final prototype featured multiple behavioural modes, haptic feedback, and wearable controls, enabling painters to interact without interrupting their work. User evaluations showed reduced physical effort and demonstrated that familiarity with the system lowered cognitive workload, highlighting the importance of predictable behaviour and clear communication in human-robot collaboration.